matrIKULASI

MATRIKULASI

DASAR DASAR EPIDEMIOLOGIOLEH

DADI S ARGADIREDJA,dr. DTM&H, MPH

DEFINITIONS

• HEALTH : - WHO 1948 Health is a state of complete physical,

mental and social well-being and not merely the absence of disease or infirmity.

- ACT no 23 ,1992 ( UU Kesehatan ) Keadaan sejahtera dari badan jiwa an sosial yang

memungkinkan setiap orang hidup produktif secara sosial dan ekonomis

- LAST, 1987 A state of equilibrium between humans,

and the physical , biologic, and social environment compatible with full functional activity

• KESEHATAN: - WHO 1948 Kesehatan adalah keadaan sempurna fisik, mental dan kesejahteraan sosial dan bukan hanya ketiadaan penyakit atau kelemahan.

- Tidak ACT 23, 1992 (UU Kesehatan) Keadaan Hidup sejahtera USING jiwanya suatu badan terkait masih berlangsung Orang Yang sosial memungkinkan produktif secara ekonomis Dan sosial - LAST, 1987 Sebuah keadaan keseimbangan antara manusia, dan fisik, biologis, dan lingkungan sosial yang kompatibel dengan aktivitas fungsional penuh

Definitions................cont• PUBLIC HEALTH: WINSLOW 1920 the state and the art of 1) of

preventing disease 2) prolonging life and 3) promoting physical health and efficiency through organized community effort for: a)the sanitation of the environment b) control of community infections. c)the educations of the individuals in personal hygiene d) the organization of medical and nursing service for the early diagnosis and preventive treatment and e) development of social machinery which will ensure to individuals in the community a standard of living with adequate for the maintenance of health.

to organizing these benefits as to enable every citizen to realize his birthright of health and longivity.

• KESEHATAN PUBLIK: Winslow 1920 negara dan seni 1) mencegah penyakit 2) memperpanjang hidup dan 3) meningkatkan kesehatan fisik dan efisiensi melalui usaha masyarakat yang diselenggarakan untuk: a) sanitasi lingkungan b) pengendalian infeksi komunitas. c) pendidikan dari individu-individu dalam kebersihan pribadi d) organisasi pelayanan medis dan perawatan untuk diagnosis dini dan pengobatan dan pencegahan e) pengembangan mesin sosial yang akan menjamin kepada individu dalam komunitas standar hidup yang memadai untuk pemeliharaan kesehatan. untuk mengatur manfaat ini untuk memungkinkan setiap warga negara untuk menyadari itu hak kelahiran kesehatan dan longivity.

Definitions...................cont

• LAST 1988 ;effort organized by society to prevent, promote, and restore the people’s health. It is the combination of science,

skills and beliefs that is directed to the maintenance and improvement of the health of all people through collective or social actions.

• IOM 1988 what we as a society do collectively to assure the conditions for people to be

healthy.

• LAST 1988; upaya yang diselenggarakan oleh masyarakat untuk mencegah, mempromosikan, dan memulihkan kesehatan masyarakat. Ini adalah kombinasi dari ilmu pengetahuan, keterampilan dan keyakinan yang diarahkan pada pemeliharaan dan peningkatan kesehatan semua orang melalui tindakan kolektif atau sosial.IOM 1988 apa yang kita lakukan sebagai masyarakat kolektif untuk memastikan kondisi bagi orang-orang yang akan sehat.

Definitions.....................cont

• EPIDEMOLOGY:

Mausner & Bahn 1974 ;

the study of the distribution and determinats of diseases and injuries in human populations

LAST 1995,WHO 1993.

The study of distribution and determinants of health-related states or events in the specified populations and the applications of the study to control of health problems.

• EPIDEMOLOGY: Bahn Mausner & 1974; studi distribusi dan determinats penyakit dan cedera dalam populasi manusia LAST 1995, WHO 1993. Studi tentang distribusi dan faktor-faktor penentu kesehatan yang berhubungan dengan negara atau peristiwa di populasi tertentu dan aplikasi studi untuk mengendalikan masalah kesehatan.

definitions.................cont

HARFIAH:

Epi = di,pada Demos = masyarakat dan

Logos = ilmu

Epidemi = wabah, outbreak ,Logos= ilmu

HISTORY

• 2000 years ago : Hypocrates environment influence the occurance of disease.

• 1848 John Snow cholera related with contaminated water.

• 1906 Sinclairrelationship b/w occupational environment and disease/injuries.

• 1959 Doll & Hill relationship b/w cigarette smoking and lung cancer.

• Now communicable disease epidemiology remain of vital importance in developing and developed countries. Noncommunicable disease epidemiology is also important in the future.

• 2000 tahun yang lalu: pengaruh lingkungan Hypocrates terjadinya penyakit.1848 John Snow kolera terkait dengan air tercemar.1906 b Sinclair hubungan / lingkungan kerja w dan penyakit / cedera.1959 Doll & Hill hubungan b / w rokok merokok dan kanker paru-paru.Sekarang epidemiologi penyakit menular tetap sangat penting dalam mengembangkan dan negara-negara maju. epidemiologi penyakit menular juga penting di masa depan.

DEVELOPMENT OF EPIDEMIOLOGY AS A SCIENCE

• Before 1950 acute onset epiemiology.• In 1950 Doll & Hill tobacco smoking and lung

cancer landmark finding of modern epidemiology

• In 1960s -1970s developed quicklycodification of methodologies specific to the study of chronic , emerging,

reemerging disease• In 1990s specialities in epidemiology eg

nutritional epidemiology,environmental epidemiology, occupational epidemiology etc.

PENGEMBANGAN SEBAGAI ILMU Epidemiologi A

• Sebelum 1950 epiemiology onset akut.Pada tahun 1950 Doll & Hill tembakau merokok dan kanker paru-paru menemukan tengara epidemiologi modernPada tahun 1970-an 1960-an berkembang cepat kodifikasi metodologi tertentu untuk studi kronis, muncul, reemerging penyakitPada 1990-an spesialisasi dalam epidemiologi epidemiologi misalnya gizi, epidemiologi lingkungan, pekerjaan dll epidemiologi

Development................cont

• More recently epidemiology has focused not only on the study of chronic disease but also on the emerging and re-emerging

diseases such as : HIV-AIDS, Ebola, Tuberculosis, Dengue hemorrhagic fever, West nile, Mad-cow, Severe acute respiratory syndrome (SARS).

• Epidemiologist have been called upon to participate in a wide variety of activities related to homeland security,disease surveillance. Food and water supply protection ,bioterorism

• epidemiologi Baru-baru ini tidak hanya difokuskan pada studi tentang penyakit kronis tetapi juga pada muncul dan muncul kembali penyakit seperti: HIV-AIDS, Ebola, Tuberkulosis, Dengue Demam Berdarah, nila Barat, Mad-sapi, berat sindrom pernafasan akut (SARS).Epidemiologi telah dipanggil untuk berpartisipasi dalam berbagai kegiatan yang berkaitan dengan keamanan dalam negeri, pengawasan penyakit. Makanan dan perlindungan air bersih, bioterorism

Development.............cont

• Beside understand biology,medicine,and pathology ,epidemiologist should know foundation in a number of other field.What did each of the following fields contribute to the development of epidemiology?

Statistics:

epidemiology is population based,study group of people rather than individual the data collected need statistical analyses.

• Selain memahami biologi, kedokteran, dan patologi, epidemiologi harus mengetahui dasar di sejumlah field.What lain melakukan masing-masing bidang berikut memberikan kontribusi terhadap pengembangan epidemiologi? Statistik: epidemiologi adalah penduduk berdasarkan, penelitian sekelompok orang bukan individu data yang dikumpulkan perlu analisis statistik

Development.......................cont

Social sciences(sociology. Psychology, anthropology) are foundational field for epidemiology because the vast majority of epidemiologic studies are observational.

Epidemiologist must understand process and forces in community.

Computer technology: Some time epidemiologist study large group of

people and collect numerous data over time for each person. need software capable of storing,managing and analyzing large amount of data.

• ilmu-ilmu Sosial (sociology. Psikologi, antropologi) adalah bidang dasar untuk epidemiologi karena sebagian besar studi epidemiologi adalah observasional. Epidemiologi harus memahami proses dan kekuatan dalam masyarakat. Teknologi komputer: Beberapa studi epidemiologi waktu besar kelompok orang dan mengumpulkan banyak data dari waktu ke waktu untuk setiap orang. perangkat lunak harus mampu menyimpan, mengelola dan menganalisis sejumlah besar data.

Development..............cont

Managerial science:

-epidemiologist study volunteersmust manage “volunteer process” .The right of human subjects should be potected.

-Study consist of many teams so epidemiologist should have managerial skill .

• Manajerial ilmu: Penelitian epidemiologi relawan- harus mengelola "relawan proses" Hak subyek manusia harus potected..-Studi terdiri dari banyak tim sehingga epidemiologi harus memiliki keterampilan manajerial.

• THE SCOPE OF EPIDEMIOLOGY:-for many yearsrestricted to infectious disease.-After infectious disease was satisfactory

controled disease of later life (vascular,arthritides,malignancy)

-centuries ago non infectious- Mid 18 th century lead poisoning,scurvy- Now all diseases ,conditions, and health related

events mental illnes, suicide, drug addiction,and injury.

• RUANG LINGKUP Epidemiologi:-Selama bertahun-tahun terbatas pada penyakit menular.Penyakit menular Setelah cukup memuaskan penyakit terkendali kemudian hidup (vaskular, arthritides, keganasan)-Abad yang lalu non menularPertengahan abad 18 mengakibatkan keracunan, penyakit kudis- Sekarang semua penyakit, kondisi, dan peristiwa kesehatan terkait illnes mental, bunuh diri, kecanduan narkoba, dan cedera.

NATURAL HISTORY OF DISEASE

• It is important to understand natural history of disease in order to understand different approaches to prevention and control. Each disease has its own life history.

1.Stage of susceptibility: In this stage disease has not developed, but the

groundwork has been laid of factors which favors to its occurance (fatigue.alcoholism. High serum cholesterol etc) Factor is called Risk factor.

NATURAL HISTORY OF DISEASE

• Sangat penting untuk memahami sejarah alam penyakit untuk memahami pendekatan yang berbeda untuk pencegahan dan pengendalian. Setiap penyakit memiliki sejarah hidup sendiri.1.Stage suseptibilitas: Pada tahap ini penyakit belum berkembang, tapi dasar telah diletakkan faktor yang menguntungkan dengan kejadian tersebut (fatigue.alcoholism Tinggi serum. Dll kolesterol) Faktor ini disebut faktor risiko.

Natural....................cont

2.Stage of presymptomatic disease In this stage no manifest disease, but usually

pathogenic changes have started to occur. The changes are below clinical horizon Example of thisi presymptomatic disease are atheroscerotic changes in coronary vesels before any sign and symptoms of illnes.

3. Stage of clinical disease In this stage sufficient anatomic and functional

changes have occurred, so that there are recognizable signs and symptoms.

2.Stage penyakit presymptomatic Pada tahap ini tidak ada penyakit yang nyata, tetapi biasanya perubahan patogen sudah mulai terjadi. Perubahan tersebut di bawah ini Contoh cakrawala klinis penyakit presymptomatic thisi adalah perubahan atheroscerotic di vesels koroner sebelum tanda-tanda dan gejala illnes. 3. Tahap penyakit klinis Pada tahap ini perubahan anatomi dan fungsional yang cukup telah terjadi, sehingga terdapat tanda-tanda dan gejala dikenali.

Natural .....................cont

4.Stage of disability

- some diseases run their course and then resolve completely, either spontaneously or under the influence of therapy.

- give rise to a residual defect of shot or long duration.

- disease with self-limited chronic disability.

-disability = limitation of a person’s activities

4.Stage kecacatan - Beberapa penyakit menjalankan program mereka dan kemudian menyelesaikan sepenuhnya, baik secara spontan atau di bawah pengaruh terapi. - Menimbulkan cacat sisa tembakan atau memakan waktu lama. - Penyakit dengan diri-terbatas cacat kronis. -Cacat = pembatasan kegiatan seseorang

LEVEL OF PREVENTION

• Primary prevention;

prevention of the occurance of disease consist of two major measures :

- General health promotion like healthy living (good nutrition, adequate clothing, shelter, rest and recreation),

- Specific protective measures like immunization, sanitations, protection against accidents and occupational hazards

LEVELS..................CONT.

• Secondary prevention -with early detection and prompt treatment of

disease, it is sometimes posible to either cure disease at the earliest stage possible or slow its progression, prevent complication.

- on a community basis, early treatment of person with infectious disease may protect others from acquiring infection and thus provides at once secondary protection for the infected individuals and primary prevention for their potential contacts.

Levels.....................cont

• Tertiary prevention

-This consists of limitation of diasability and rehabilitation. So in this stage we prevent disability and dependency

Variations in severity of disease

• Inapparent infection frequent: tbc • Clinical disease common measles• Infection usually fatal rabies

Inapparent mild mod sv ftl

In mild moderate sv ftl

Sv fatal

USES OF EPIDEMIOLOGY

• Causation : genetic factor

good health --------ill-health

environment

factor (including

behavior)

• Natural history death

good health - subclinical -clinical----

recovery

Uses of.....................cont

• Description of status of populations.

proportion with ill health change over time ,change with age etc.

• Evaluation of intervention: treatment/med care

good health ill health

heath promotion

promotive measures

PH services

DETERMINANTS OF HEALTH

DADI S ARGADIREDJA,dr,DTM&H, MPH Program Studi Ilmu kesehatan Masyarakat

Fakultas Kedokteran UNPAD

DETERMINANTS OF HEALTH

• ENVIRONMENT DETERMINANTS”-Prior to industrial revolution sanitary measurement had limited impact on the incidence of desease in society. society were susceptible to waterborne, foodborne. But caused by limitted size of town and cities no epidemic

-during industrial revolution housing for worker were bad (dwelling) class difference,

- Prior 18 th century class difference in mortality < . - 1970 -1985 in developed countries categorical

pollutants removed from the air (lead.CO, SO etc) housing were also improved.

Determinans..............cont

• Environmental factors that affect health include - Life support food,water, Air. - Physical factors Mechanical, Accoustical, Electrical, Thermal, Ionizing Radiation. -Biologic factors Microorganism,toxin. biologic wastes, Biologic antagonist, animals Plant, Allergen. - Psychosocial crowding, demands,physical time. - Chemical factors Inorganic, organic, products complexes

Product complexes such as :

. Combustion products’

. Macromolecular products

. Industrial wastes

. Agricultural wastes including fertilizer

, pestisides. And herbicides

The environmental field is full of hazard .Their complexity is increasing as technology provides us with new products and processes

Determinants...............cont

• LIFE-STYLE - smoking- lung ca, peptic ulcers - substance / drug abuse . addiction - Exercise /physical activity heart disease diabetes, osteoporoses. - Diet coronary heart disease. Stroke, colon cancer. - Unprotected sex STD, HIV-AIDS, Hepatitis, Unwanted pregnancies, Cervical Ca

Determinants...........cont

• BIOLOGY -in earlier centuries biologic phenomenons were the dominant determinants of health -Biology as determinants of health not just a matter of pathogenic

microorganism .Interactions of microorganism with environment and lifestyle had decreased infectious disease but in other side produce new disease eg : HIV-AIDS, Legionnair’s disease,Lyme disease, Toxic shock syndrome

- Genetic.

-arthritic histocompatibility locus of chromosome

-alzheimer caused by protected genes

“turned off”

-Now reseacher can examine the chromosomal structure of cell from the amniotic fluid genetic marker. At the present time it is not possible to alter genetic structure in human.

Gender ; Female : breast ca ,ca colon, Man : hemophilia, motorcycle accident

• SOCIO-ECONOMIC- Race Black White, Hispanic- Poverty In every determinants low income people always at

disadvantages Government conduct program ‘Safety-net’

-social ;

children live in family with social stress greater risk of illnes and injuries

people live socially isolateddeath rates

2 -4 X higher

- income disparity

HEALTH RISK

DADI S ARGADIREDJA,dr,DTM&H,MPH

Program Studi Ilmu Kesehatan Masyarakat

Fakultas Kedokteran

UNPAD

HEALTH RISK• Risk means - A probability - A factor that raises the probability of an adverse outcome. - A consequences. - A potential adversity of threat.• Focus on risk to health> -is key to preventing disease and injury -many health risk are result of deliberate decision by

individuals consciously trying to make the best choices for themselves

- to make decision wisely

Health risk...............cont

- health risk is the key for research priorities

- prioritization for health policy and research

-public perception of risk plays a role in risk analyses

-Risk assesment,communication, risk management. Cost effectiveness and policy development form focus of the report.

• RISK ASSESMENT - Definition :is the systematic scientific characterization of potential adverse

health effects resulting from human exposures to hazardous agents and situation.

hazard = intrinsic toxic properties

• RISK MANAGEMENT: Refer to the process by which policy actions are chosen to deal with

hazards identified in the risk assesment/ risk characterization

RISK COMMUNICATION Is the challenging process of making risk assesment and risk

management information comprehensible to community group,lawyer,politician, judges,business-man, labour and environmentalis

Risk assessment

• Root of risk assessment Environment sector

• Analog with assessing population attributable risk in epidemiology.

• Four elements of risk assessment: 1 .Hazard identification chemical X cause liver damage

2 Dose response assessmenthealth affect depend on amount of exposure. 3 Exposure assessment.distribution and concentration of pollution

in the env combine w/behavior and physiology estimate amount of polutant in which humans are exposed.

4 Risk characterization combines risk exposure and dose responsecalculate the estimated health risk.

Risk perception..........cont

• Risk had different meaning different group of people,

• Be influenced by larger social and cultural context.

• Often lead to intense public controversy.

• These differences have to be understand and resolve

• Risk perception are being influenced by 3 factors: -power/influence of special interest group

-increasing influence of global mass-media -globalisation increase risk in middle and low income

countries

Risk communications

• Have 6 main components 1) the aims and objectives, 2) framing the contents and messages.3)population and target audience.4)sources and presentation of information. 5) the distribution and flow of information, 6) mechanism of dialog and conflict resolutions.

• Designed for a health program to be implemented by an expert regulatory body.

• More successful if better dialogue b/w parties.• Influence by powerful interest group outside the

government.

DISTRIBUTIONS

• TIME: -Hour distribution incubation period very short, toxic substance. - Daily - Weekly for surveillance epidemiology. - Monthly - Seasonal summer,Rainy season. - Yearly - Cyclic changes annual or other periodicity eg measles epidemic every 3 years. - Secular trends long periods, years or decades

Distributions..............cont

• PLACE :- Natural boundariescharacterized by particular

environment and climate (Temp, humidity, rainfall,water supply, mineral in soil etc)

- Physical boundaries - Political subdivision National, provinces,

District,municipals, sub district, villages etc- Mapping of environmental factor.- Rural-urban differences.

Distributions...............cont - tnternational comparison. - study on migrants

PERSON :- Age :measles,chickenpox,mumps occur mainly in children (disease w/

life-long immunity)- Sex death rate M>F but morbidity rate F>M. Mammae ca F>M, Depression F>M.- Etnic group and color Black have higher death rate than Hispanic and

white.- Social-class white collar, blue collar- Occupation asbestosis, lung fibrosis,injury.- Marital status- Other family variables family size, birth order, maternal age, parental

deprivation

EPIDEMIOLOGIC MODELS

• The Epidemiologic triangle.

host

agent environment

• The Web of causation

Epid...................cont

• The Wheel

environment

host

Genetic core

• Ecologic model - inter-relation of factors

• Ecologic models

MULTIPLE CAUSATION AGENT : - Biologic microorganism virus, bacteria, ricketzia, protozoa, fungi, metazoa -Physical Lead, asbes, CO etc

-Social Maternal deprivation.

Multiple .............cont

• HOST (Intrinsic factors) -genetic factors -immunity -personality• ENVIRONMENT (extrinsic factors) -Biological environment Agents of disease, reservoir, vectors, plants and animal(source of food) -Social environment. eating habits, the way of cooking - Economic environment low income, health service payment,

Multiple...............cont

-ideology and politics

social conflict, war death ,injuries

-physical environment :

heat, light, air, water radiation,gravity

atmoshpheric pressure, chemical

MEASURES OF DISEASE FREQUENCY

• Poplation at risk: the part of population which is susceptible to a

disease;( Ca cervix)

Total Population all woman pop at risk woman age 25-69

womanMan woman

• Prevalence & Incidence

Prevalence rate :E existing cases/tot pop

Incidence rate : E new cases/ pop at risk

P = I x d d =duration

P .> I Diabetes P < I Influensa

• Factors influencing prevalence rate Increased by : -longer duration of disease. -prolongation of life of patient w/o cure - increase of new cases - in migration case - out migration of healthy people - in migration of susceptible(beresiko) people - improved diagnostic

• Decreased by:

-shorter duration of disease.

-High case fatality rate

-Decrease of new cases

-In migration healthy people

-Out migration of cases

-Improve cure rate.

• Prevalence rates are influenced by so many factors ,

- unrelated to disease causation - don’t usually provide strong evidence of causality. - helpful in assesing the need for health care and planning of health services. - often used to measure the occurance of conditions for which the onset of disease maybe gradual( ex maturity onset of DM)

• Incidence rate. number of new cases/ population at risk

Last (1995) most accurate way to calculate

incidence person-time incidence rate no of people who get a disease in spesified period / sum of

the length of time during which person in the populatioh is

at rik

Cumulative incidence rate or Risk

is the simpler measure of occurance of a disease or

health status

CI= number of people who get disease during a specified

period / number of people free of the disease in the population at riask at the beginning of the period.

CI used : -often cases /1000 population. -probibility/risk of individual in the popula tion getting the disease during specified period. -period can be of any length but usually years or a whole life time

• Case Fatality

number of death from a disease in specified period / numbr of

diagnosed casesof thedisease at the same period

- in percent(%)

- a measure of the severity of a disease.

- strictly speaking ; fatality/case ratio but is often

called case fatality rate.• Interrelasionship

Pr rate = Inc rate x averageduration of

disease

• Calculation of disease occurance : 1.----------------------------------------- 7.yrs 2.----------------------------------------- 7 yrs 3---------xxxxxxxxxxxx D 2 yrs 4------------------------------------------ 7 yrs 5-----------------??????????????? 3 yrs 6---------xxxxxxxxxxxxxxxxxxxxxxx 2 yrs 7----------------------------- xxxxxxxxx 5 yrs .1........2.......3......4......5.....6... .7 years ob

• Notes ---------- healthy period

xxxxxxx disease period

?????? Lost of follow up

D death

Calculation :

• I ncidence rate = 3 / 33 9.1cases /

100 person-years

• Cumulative incidence rate = 3 / 7 43 cases pe 100 persons during 7 yrs• Average duration of disease = 10 / 3 3.3 years.• Prevalence rate at 4th year = 2 / 6 33 cases per 100 persons. Prevalence rate = 9,1 x 3.3 30 cases per 100 population

• Mortality: - crude death/mortality rate = number of of death in specified period / Ave rage of population during that pe riod

- Age and sex death rate = number of death occuring in a specific age and sex group of population in a defined area during specified period / Estimated total popu

lation of the same age and sex group of the population in the same area during the same period’ - Infant mortality rate = number of death children < 1 year / number of live birth in the same year. Countries can be devided into : High income countries ,Medium income ; Low income countries Notes : China and Sri Lanka (low income countries have low infant mortality rate. (38, 19 /1997

-Maternal mortality rate = maternal pregnancy related death in one year / Total birth in the same year. - Life expectancy = the average number of years an individual of a given age is ex pected to live if current mortality rates continue. life expectancy at birth (E o ) life expectanct at 60 ( E 60 )

- QALY’s = quality adjusted life years\

- DALY’s = disability adjusted life years

for esimate cost effectiveness of various

procedure

Standardized rates

Age standardized death rates = age adjusted

rate

Standariation direct

indirect disease rates in

standard population

- applied in population being compared. Indirect> direct’ can compare for mortality or morbidity. MORBIDITY Death rate is useful for investigating disease with high

case fatality rate. In low CFR morbidity is more useful The source of data - Notifiable disease report - Hospital admission rate - Cause routin data not accurate collecting new data need screening and questionair.

DISABILITY : WHO definition Impairment= any loss or abnormality of

psychological,physiological or anatomical structure or function. disability = any restriction or lack of ability to perform an activity in the maner or within the range

considered normal for a human being. handicap = a disadvanted for agiven individual resulting from impairment or a disability that prevent the fulfilment of a role that is normal for that individual, COMPAIRING DISEASE OCCURANCE :

a. Absolute comparison - Risk difference = Exess risk = Absolut risk a difference in rates of occurance b/w exposed and non exposed groups - Atributable fraction (exposed) = Etiological fraction

risk diference / rate of occurance among the exposed population. Atributable fraction is useful for asses ing priorities for P.H action - Population attributable risk (PAR) = insidence of a disease in population that iassociated with (attributable to) an exposure to risk factor(Last 1995

useful for determining the relative

importance of exposure for entire po\

pulation would be reduced if exposure

were eliminated PAR = Ip-Iu / Ip Ip = incidence rate of the

disease in total population

Iu= incidence rate of the

disease among unexpose

group

Relative comparison.= risk ratio is the ratio of the occurance of a disease among exposed people to that among the unexposed. Risk ratio is better indica tor of an assciation than risk difference. is used in assesing the likelihood that an association represents a causal relation ship. The standardized mortality ratio is the special type of risk ratio

Types of study• ----------------------------------------------------------------------------------------- Type of study alterative name unit of study ----------------------------------------------------------------------------------------------------------------- OBSERVATIONAL - Descriptive - Analytic . Ecological correlational populations . Cross sectional prevalence individuals ‘ Case control case referece individual . Cohort follow up individual

EXPERIMENTAL INTERVENTION STUDY ‘Randomized ctrl Clinical trial patients Field trials - healthy people community trial Comm intervntion communities study------------------------------------------------------------------------------------------------------------------ .

Observational studies :

- descriptive studies + based on routinely available data or data obtain

in special survey.

+ in many countries undertaken by center of

health statistic.

+ no attempt to analyse the links b/w exposure

and effect.

+ usually based on death statistics and may exa

mine pattern of death by age,sex,and ethnicity

during soecified time periods or in various countries

Ecological studies: + initiate epidemiological process + unit analyes is population or group. + Socioeconomic confounding is potential problems in this study. + Simple, attractive, but difficult to inter prate. + individual link b/w exposure and effect cannot be made, + An ecological fallacy or bias results if inappropriate conclusions are drawn on the basis of ecological data.

• Cross sectional studies. + measure prevalence of disease. + often called as prevalence study. + It is not easy to assess the reason for assosiation in this study. +key question whether the exposure preceeds or follow the effect.If E before any effect analysis like cohort. + easy and economic. + investigating E that are fixed characteristic

+ several countries conduct regular

cros section study.

+ helpful in assesing health care need

+ attention must be given to the

purpose of survey, questionaire must

be well design and sample chosen

must be appropriate.

Case control studies. +relative simple and economical +used to investigatecauses of disease especialy rare disease. + include people with disease and people unaffected by disease. + called retrospective study. + the dificult task is to select control + Ideally Case should be new cases + Can be prospective.

• Association b/w E and disease calculate Odd ratio Exposure + - + a b ADisease - c d B C D E

OR : ad/bc

OR ; risk ratio

Cohort studies

+ called follow up studies / incidence std

+ begin with people free of disease,

devide into Exposed and non Exposed

+ Follow whether disease develop or not

+ called prospective study

+ provide best information about caution of

disease and the most direct measure

ment of the risk of developing disease.

+ simple but need long time

+use to investigate late/ chronic effect.

+ difficulty meassuring exposure

+ cost can be reduced using hystorical cohort. + At start using healthy people posible to examine a range of outcome (example Framingham study investigate risk factor not only for cardio vascular but also for respiratory and musculoskelet al.

Application of different observational study design ----------------------------------------------------------------------- Eco CS CC Co Investigation of rare disease ++++ - ++++ - Investigation of rare cause ++ - - ++++ Testing multiple effect of cause + ++ - ++++ Study of multiple E or determinant ++ ++ ++++ ++++ Meassurement of time relationship ++ - +* ++++ Direct incidence of incidens - - +* ++++ Investigation of long latent period - - +++ -

+ = suitable - = not suitable * if prospecyive/ population base

Advantage and disadvantage----------------------------------------------------------------------------------------------

- Eco CS CC CoProbibility of : selection bias NA med high low Recall bias NA high high low loss to follow up NA NA low high confounding high med med lowTime acquired low med med highCost low med med high

NA = not applicable

Experimental epidemiology

1. Randomized controlled trial: - = randomized clinical trial - is an epidemiological experiment to study a new preventive or therapeutic regimen. - Subjects in population are randomly allocated to treatment & control group. - result are assessed by comparing the outcome of two or more groups

example : - early discharge (3 dys) of patient w/ myocard infarction. -glucose-based of Oral rehydration solu tion can be raplace by rice-based. 2, Field trials -contrast to clinical trial. -involve people who are disease free but pre sume to be a risk.

the purpose is to prevent the occurance of disease that may occure w/ relatively low frequency. - Need majo logistic and budget. - Example : trial of Salk vaccine toprevent polio field trial of vaccine against New World cutaneus leishmaniasis

3. Community trials - the treatment group not individual but communities. - appropiate for disease that have their origins in social conditions which in turn can most easily be influence by inter vention directed at group behavior as well as individual

Potential error in epidemiological studies

1. Random error =divergence due to chance aloneof an ob servation on a sample from the true population value, leading to lack of per cission in the measurement of an asso ciation - Three major source of random error (individual bio;ogical variation, campling error and measurement error)

Potensi kesalahan dalam studi epidemiologi

1. Kesalahan acak karena kebetulan aloneof ob sebuah = perbedaan konservasi pada sampel dari benar nilai populasi, menyebabkan kurangnya per cission dalam pengukuran suatu asosiasi ciation - Tiga sumber utama kesalahan acak (Bio individu; variasi ogical, campling kesalahan dan pengukuran kesalahan)

2.Sample size calculations -the desireble size of proposed study can be assessedusing standard formula - before using formula information on following variables is inquired,(required level of statistical significance, accepta ble chance of missing a real effect, magnitude of the effect under investigation , amount of disease in the population and re lative size of the groups being compared.)

Terjemahan

2. Sample perhitungan ukuran -Ukuran desireble studi yang diusulkan dapat assessedusing formula standar - Sebelum menggunakan informasi formula pada variabel berikut ini tanya, (diperlukan tingkat signifikansi statistik, accepta bel kesempatan yang hilang efek yang nyata, besarnya efek yang diteliti , Jumlah penyakit dalam populasi dan kembali lative ukuran kelompok yang dibandingkan.)

- the percision of the study can also be improved by ensuring that the groups are of appropiate relative size. - Usually become an issue in case-control study (control size)

3 Systematic error - systematic error (or Bias) occur when there is a tendency to produce results that differ in a systematic manner from the true values.

- yang percision penelitian juga dapat diperbaiki dengan memastikan bahwa kelompok yang tepat ukuran relatif. - Biasanya menjadi isu dalam studi kasus-kontrol (Ukuran kontrol)

3 Sistematik kesalahan - Kesalahan sistematis (atau Bias) terjadi ketika ada kecenderungan untuk memproduksi hasil yang berbeda dalam cara sistematis dari nilai-nilai kebenaran.

- study with small systematic error = high accuracy. Accuracy is not affected by sample size - There are more than 30 specific type of bias . - the principal biases are Selection bias and measurement / classification bias.

Selection bias - Occur when there is a systematic difference b/w characteristics of people selected for a study

and of those who are not

- Belajar dengan kesalahan sistematis kecil = tinggi accuracy. Akurasi tidak dipengaruhi oleh ukuran sampel - Ada lebih dari 30 jenis spesifik bias. - Bias-bias Seleksi utama adalah bias dan pengukuran / klasifikasi bias.

Seleksi bias - Terjadi ketika ada perbedaan sistematis b / w karakteristik orang yang dipilih untuk studi dan mereka yang tidak

example :

people who participate in study on the affect

of smoking differ in smoking habit with habit

in non responder.

- cohort of newborn follow up for 12 month

varied according to income level of parents

- study of efect of formaldehyde in feactory sick worker has gone out of the factory

• contoh: orang-orang yang berpartisipasi dalam penelitian mengenai pengaruh merokok berbeda dalam kebiasaan merokok dengan kebiasaan di non responden.

- Kohort bayi yang baru lahir sampai tindak selama 12 bulan bervariasi menurut tingkat pendapatan orang tua

- Studi tentang dampak yang diakibatkan formaldehida dalam feactory sakit pekerja yang keluar dari pabrik

Measurement bias, - occur when the individual measurement or classification of disease/exposure are inaccurate - example study using lab examination. Different lab different result. - A form of measurement bias of particular impor tance in retrospective case-control studies known as recall bias.

Pengukuran bias, - Terjadi ketika individu atau pengukuran klasifikasi penyakit / penayangan tidak akurat - Contoh studi menggunakan pemeriksaan laboratorium. Berbeda hasil laboratorium yang berbeda. - Suatu bentuk bias pengukuran impor tertentu tance dalam studi kasus-kontrol retrospektif dikenal sebagai bias mengingat.(recall bias)

- this occurs when there is a differential recall of

information by cases and control

Confounding: In the study of association b/w E to a cause/risk

factor and the occurance of disease, confounding can occur when another E exist to

the study population and is associated both with

the disease and the E being studied.

- Pengukuran bias, ini terjadi ketika ada ingat diferensial informasi dengan kasus dan kontrol

Pengganggu: Dalam studi asosiasi b / w E menyebabkan / risiko dan faktor terjadinya penyakit, pengganggu dapat terjadi jika lain E ada untuk populasi penelitian dan berhubungan baik dengan

penyakit dan E yang sedang dipelajari.

-confounding occurs when the effects of two E/

risk factor have not separated and it is there

fore incorrectly concluded that the effect is

due to one rather than to the other variable

- example study association of smoking w/ lung

cancer age become confounding factor.

- Age and social class are often confounder

confounding coffee drinking, cigarette smoking and coronary heart disease Exposure Disease (coffee drinking) (heart disease)

Confounding variable (cigarette smoking)

Control of confounding

- control confounding in study design :

by randomization, restriction and matching,

- control at analysis stage by stratification and

statistical modelling,

• VALIDITY

Is an expression of the degree to which a test

is capable of measuring what it is intended to

measure.;

Valid if its results correspond to the truth ; there

is no systematic error and random error should

be as small as possible

• Validity and reliability Validity high low -------------------------------------------------------- measured value measured value ! !!!!!!!! !!!!!!!!! high ^ ^ true value true valueReliability measured value measured value ! ! ! ! ! ! ! ! ! !!!!! low ^ ^ true value true value

• With low reliability but high validity the measured value are spread out but the mean of the measured value is close to the true value.

• A high reliability (repeatability) of the measurement doesnot ensure validity since they may all be far from the true value

• There are two type of validity (internal and external) - External validity=generalizebility the extent to which the results of the study apply to people not in it for example laboratory not involve in it. Need externel quality control of measurement and judgement about the degree to which the result of the study can be extrapolated.

- Internal validity is the degree to which the results

of an observation are correct for the particular group

of people being studied. Example :measurements of

Hb must distinguish accurately [articipants with

anemia as defined in the study. Analysis by other lab

may produce different result caused by systematic

error

UTS

Reliability - = Percision - test which give consistent results when the test is performed more than once on the same individual under the same condition - Influenced by inherent variation in the method and observer variation

Basic statistics

UAS• check Biostatistics

Causation in epidemiology

• A major goal of epidemiology is to assist in the prevention and control of disease and in the promotion of health by discovering

the cause of disease and the ways in which they can modified .

• Concept of cause -the concept of cause is not only for prevention but also for diagnosis and correact treatment -The concept of cause has different meaning in

Sebab epidemiologi

• Tujuan utama dari epidemiologi adalah membantudalam pencegahan dan pengendalian penyakit dan di promosi kesehatan dengan menemukan penyebab penyakit dan cara-cara di mana mereka dapat diubah.

• Konsep menyebabkan -Konsep penyebab tidak hanya untuk pencegahan tetapi juga untuk diagnosis dan correact pengobatan -Konsep menyebabkan memiliki makna yang berbeda dalam

different context and no definition is equaly apprropriate in all science

- A cause of a disease is an event, condition. Characteris

tic or a combination of those factor which play an important role producing the disease .

- A sufficient cause is not usually a single factor but often

comprises several components.In general it is not necessary to identified all the components of a sufficient cause before efective prevention can take place ,since the removal of one component may interfere with the action of the other and this prevent the disease.

• konteks yang berbeda dan tidak ada definisi equaly apprropriate dalam semua ilmu - Penyebab penyakit adalah sebuah peristiwa, kondisi. Characteris tic atau kombinasi dari faktor yang memainkan peran penting menghasilkan penyakit. - Penyebab yang memadai biasanya tidak menjadi faktor tunggal tetapi sering terdiri dari beberapa components.In umum tidak perlu untuk mengidentifikasi semua komponen penyebab cukup sebelum pencegahan efektif dapat terjadi, karena penghapusan salah satu komponen dapat mengganggu tindakan yang lain dan mencegah penyakit.

Each sufficient cause has a necessary cause as a component Example : In food-borne outbreak it maybe found that chicken salad and creamy dessert were both sufficient cause of salmonella diarrhoea. Adanya salmonella is a necessary cause of this disease. Simillarly many in tuberculosis there are different com ponents in causation of tuberculosis but tuber cle bacillus is a necessary cause.

• konteks yang berbeda dan tidak ada definisi equaly apprropriate dalam ilmu semua Setiap menyebabkan cukup memiliki sebab diperlukan sebagai komponen Contoh: Pada makanan-ditanggung out- istirahat itu mungkin menemukan bahwa ayam dan salad krim dessert berdua menyebabkan cukup salmonella diare. salmonella Adanya adalah diperlukan penyebab penyakit ini. Simillarly TB banyak terdapat com berbeda ponents dalam penyebab TB tetapi umbi basil cle merupakan penyebab diperlukan

• Cholera expposure to effect of cholera contaminated toxin on bowel genetic factor water wall cells

malnutrition crowding poverty increased ingestion cholera suscepti cholera bility vibrio o----------RISK FACTOR-------------------o-------mechanism for CH

•

genetic factor exposure to tissue

bacteria invasion

malnutrition

crowding Susc inf tuberculosis

host

poverty

o-----risk factor of tbc--------------o--------mechanisms of tbc--

• Single and multiple causes -Pasteur work on microorganism led to the formu lation, first by Henle and then by Koch the

following rules for determining whether a specific living organism causes particular disease:

-the organism must be present in every case of the disease. -the organism must be able to be isolated and grown up to pure culture

• Tunggal dan beberapa penyebab kerja-Pasteur pada mikroorganisme yang menyebabkan formulation, pertama oleh Henle dan kemudian oleh Koch berikut aturan untuk menentukan apakah suatu spesifik organisme hidup menyebabkan penyakit tertentu: -Organisme harus hadir dalam setiap kasus penyakit ini. -Organisme harus dapat terisolasi dan tumbuh kultur murni

- the organism must, when inoculated into a

susceptible animal cause the specific disease

- the organism must then be recovered from

the animal and identified

-First example for these rules was Anthrax

-For most diseases (infectious and non infectio-

us) Koch’s rules for determining causation are

inadequate.Many causes are usualy operating

and single factor(ex: sigaret smoking )

• organisme harus, ketika diinokulasi ke dalam hewan rentan menyebabkan penyakit tertentu

• Organisme kemudian harus pulih dari binatang dan diidentifikasi - contoh Pertama untuk aturan ini adalah Anthrax (bisa dipakai senjata biologis) - Untuk kebanyakan penyakit (menular dan non-infectio kita) Koch aturan untuk menentukan penyebab yang penyebab inadequate.Many biasanya beroperasi dan satu faktor (ex: merokok Sigaret)

but no causative organism appear.

- Koch’s rules are of value only when:

. The specific cause is an overpowering in

fectious agent.

. Uncommon situation suceptibility due to

other factor.

. Sufficient amount of the agent (infective

dose )

organisme harus, ketika diinokulasi ke dalam hewan rentan menyebabkan penyakit tertentu namun tidak ada organisme kausatif muncul. - Peraturan Koch adalah nilai hanya jika: . Penyebab khusus adalah sangat kuat dalam fectious agen. . Jarang suceptibility situasi karena faktor lainnya. . Cukup jumlah agen (infektif dosis)

• Factors in causation; Four type of factor play a part in causationof disease. All

maybe necessary but they are rarely sufficient to cause a particular disease or state: - Predisposing factors such as age, sex and previous illness may create a stae of susceptibility to disease agent. - Enabling factors such as low income,poor nutrition, bad housing and inadequate medical care may favour development of disease

• Faktor penyebab; Empat jenis faktor memainkan peran dalam penyakit causationof. Semua mungkin diperlukan tapi mereka jarang cukup untuk menyebabkan penyakit tertentu atau negara: - Faktor predisposisi seperti umur, jenis kelamin dan sebelumnya penyakit bisa membuat STAE kerentanan terhadap penyakit agen. - Mengaktifkan faktor seperti pendapatan rendah, gizi buruk, buruk perumahan dan perawatan medis yang tidak memadai dapat mendukung perkembangan penyakit

Conversely circumtances that assist in recovery from

illness or in the maintenance of good health could

also be called enabling factors.

- Precipitating factors such as exposure to a specific

disease agent or noxious agent may be assosiated

with the onset of disease or state

-Reinforcing factors such as repeated exposur and

unduly hard work may aggravate an established

disease or state.

The term “risk factor “ is commonly used to describe

• Sebaliknya circumtances bahwa membantu dalam pemulihan dari sakit atau dalam pemeliharaan kesehatan yang baik bisa juga disebut memungkinkan faktor. - Curah faktor-faktor seperti pajanan terhadap suatu yang spesifik Penyakit agen atau agen mungkin berbahaya hUbungannya dengan timbulnya penyakit atau keadaan -Memperkuat faktor-faktor seperti exposur diulang dan terlalu keras bekerja dapat memperburuk terbentuk dengan penyakit atau negara. Faktor "risiko istilah" umum digunakan untuk menggambarkan

factors that are positively associated with the risk of development of a disease but are not sufficient to cause of disease. Some risk factors( e.g tobacco smoking) are associated with several disease. Epidemiological study can measure the relative contribution of each factor to disease occurance , and corresponding potential reduc tion in disease from the elimination of each risk factor.

Interaction : the effect of two or more causes acting together is often greater than would be expected on the basisof summing

faktor yang positif berkaitan dengan risiko Pembangunan suatu penyakit tetapi tidak cukup untuk penyebab penyakit. Beberapa faktor risiko (e.g merokok tembakau) adalah berhubungan dengan beberapa penyakit. Penelitian epidemiologi dapat mengukur kontribusi relatif dari masing-masing faktor terjadinya penyakit, dan sesuai potensi reduc SI penyakit dari penghapusan masing-masing faktor risiko.

• Interaksi: efek dari dua atau lebih penyebab sering bertindak bersama-sama lebih besar dari yang diharapkan pada jumlah basiso

the individual effect. This phenomenon is called Interac-

tion . Example :High risk of lung cancer in a people

who smoke and exposed to asbestos dust.

• Establishing the cause of disease: Causal inference is the term for the process of determin

ing whether observed assiciation are likely to be causal.

Before an association is assessed for the possibility that

it is causal bias and confounding should be excluded

• efek individual. Fenomena ini disebut interaksi- kasi. Contoh: Tinggi risiko kanker paru-paru pada orang yang merokok dan terkena debu asbes.Menetapkan penyebab penyakit: inferensi kausal adalah istilah untuk proses determin ing assiciation diamati apakah kemungkinan akan kausal. Sebelum asosiasi dinilai untuk kemungkinan bahwa itu adalah bias kausal dan pengganggu harus dikecualikan

• assessing the relationship b/w a possible cause and an

outcome observed association could it be due to selection or measurement bias

coud it be due to confounding could it be a result of chance

could it be causal

apply guidelines and make judgement

• Temporal relationship temporal relationship is crucial the cause must

preceed the effect. This usually self-evidence ,although difficult may arise in case-control and cross sectional study when measurement of the possible cause and effect are made at the same time and the effect may in fact after the exposure. In cases where the cause is an exposure that can be at different levels it is essential that high enough level be reached before the disease occur for the correct temporal relationship to exist

repeated measurement (time&place) trengthen the evidence

• Hubungan temporal hubungan temporal yang penting menyebabkan harus mendahului efeknya. Hal ini biasanya diri-bukti, meskipun sulit mungkin muncul dalam kasus-kontrol dan studi cross sectional saat pengukuran penyebab yang mungkin dan efek yang dibuat pada waktu yang sama dan efeknya mungkin sebenarnya setelah eksposur. Dalam kasus di mana penyebabnya adalah sebuah pemaparan yang dapat pada tingkat yang berbeda adalah penting bahwa tingkat yang cukup tinggi dicapai sebelum penyakit terjadi karena hubungan temporal yang benar ada pengukuran ulang (waktu & tempat) trengthen bukti

• Guidelines for causationTemporal relation does the cause preceede the effect (essential)Plausibility is the association consis tent w/ other knowledge ( mech of action evidence from exp animals)Consistency have similar results been shown in other studiesStrength what is the strength of association b/w the cause and effect ( relative risk )Dose-response is increase exposure to the possible cause relationship increase effect.Reversibility removal of possible cause reduction of riskStudy design evidence based on strong study designJudging the how many lines of evidence lead to the conclution

Pedoman untuk hal menyebabkanTemporal relation :hubungan temporal tidak penyebab preceede efek (penting)Masuk akal adalah asosiasi consis tenda w / pengetahuan lainnya (Mech bukti tindakan dari exp hewan)Konsistensi memiliki hasil yang sama telah ditunjukkan dalam penelitian lainKekuatan apa kekuatan asosiasi b / w menyebabkan dan dampak (risiko relatif)Dosis-respons adalah meningkatkan eksposur ke penyebab meningkatkan hubungan efek.Kebalikan menyebabkan penghapusan kemungkinan penurunan risikoStudi desain bukti berdasarkan desain studi yang kuatMenilai bagaimana banyak baris timbal bukti untuk disimpulkan

• Plausibility : an association is plausible and that more likely to be

causal. If consistent with other knowledge.eg laboratory

experiments. Example predominant view of cholera in 1830 was “miasma “ but Snow showed that evidence was “ contagion “ Lack of plausability may simply reflect lack of medical knowledge example sceptism that still

exist about therapeutic effect of acupuncture and home-

eopathy cause by absence of information about a plausi

ble biological mechanism.

• Masuk akal: asosiasi adalah masuk akal dan yang lebih cenderung menjadi penyebab. Jika konsisten dengan laboratorium knowledge.eg lain percobaan. Contoh tampilan dominan dari kolera pada tahun 1830 adalah "racun" tapi Salju menunjukkan bukti yang "menular" Kurangnya plausability hanya mungkin mencerminkan kurangnya pengetahuan sceptism contoh medis yang masih ada efek tentang terapi akupunktur dan rumah- eopathy disebabkan oleh tidak adanya informasi tentang plausi

bel mekanisme biologis.

• Consistency consistency is demonstrated by several studies giving

the same result.This is particulary important when a variety of design are used in different setting.

- Technique Metaanalyses (combines the result of a number of well-design trials each of which deal with a

relatively small sample, in order to obtain a better overall

estimate of effect.

• Konsistensi konsistensi yang ditunjukkan oleh beberapa studi memberikan yang result.This sama khususnya penting ketika berbagai desain digunakan dalam setting yang berbeda.Teknik Metaanalyses (menggabungkan hasil dari sejumlah percobaan baik desain masing-masing yang berhubungan dengan sampel relatif kecil, untuk memperoleh lebih baik secara keseluruhan perkiraan dampak.

• Strength -a strong association b/w possible cause and effect as

measures by the size of the risk ratio is more likely to be causal than is a weak association

- relative risk greater than 2 can be consider strong - the fact that an association is weak does not preclude it from being causal

• Dose-response relationship - a dose response relationship occurs when changes in

level of possible cause are associated with changes in

• Kekuatan -A, b asosiasi yang kuat / w penyebab dan akibat sebagai ukuran dengan ukuran rasio risiko lebih mungkin sebab-akibat dari adalah asosiasi lemah - Risiko yang relatif lebih besar dari 2 dapat mempertimbangkan kuat - Fakta bahwa asosiasi lemah itu tidak menghalangi dari yang kausal Dosis-respons hubungan - Hubungan respon dosis terjadi ketika perubahan tingkat penyebabnya berhubungan dengan perubahan

prevalence or incidence of the effect

- the demonstration of a clear dose response relation

ship in unbiased studies provides strong evidence for

a causal relationship b/w exposure or dose and

disease.

• Reversibility When the removal of a possible cause result in reduced

disease risk, the likelihood of the association being causal is strengthen

prevalensi atau kejadian efek - Demonstrasi dari hubungan respon dosis jelas kapal dalam studi tidak bias memberikan bukti yang kuat untuk hubungan kausal b / w paparan atau dosis dan penyakit. Hal dpt dibalik Ketika penghapusan akibat risiko yang mungkin menyebabkan penyakit berkurang, kemungkinan asosiasi menjadi penyebab adalah memperkuat

• Study design the ability of a study design to prove causation is a most

important consideration. The best evidence comes from well-designed, competency conducted randomized control trial.

- Other experimental studies such as field and community trials are seldom used to study causation

- Evidence comes most often from observational studies - Cohort studies ae the next best design because when

well conducted, bias is minimized, - Although case control studies are subject to several

forms of bias the result from large well-design investig

of this kind provide good evidence for a causal nature of an association

- ecological study provide the least satisfactory type of evidence on causality because of danger of incorrect extrapolation to individuals from data on regions and countries

Relative ability of studies to prove causation

randomized controlled trials-------------------strong

Cohort studies------------------------------------moderate

Case control studies-----------------------------moderate

Cross section studies--------------------------- weak

Ecological studies ------------------------------- weak

• judging the evidence Regrettably there are no completely reliable

criteria for determining whether an association is causal or not . Causal inference is usually tentative and judgement must be made on the basis of the available evidence uncertainly always remain

Communicable disease epidemiology

• Communicable =infectious • Communicable disease is an illness caused by

transmission of the specific infectious agent or its toxic product from infected person or animal to a susceptible host either directly or indirectly

• In developed countries acute upper respiratory

infection (ARI) are responsible for a great deal of

morbidity and time off work

• In developing countries communicable disease are still the major cause of both morbidity and mortality

Epidemiologi penyakit menular• Menular = menular

Penyakit Menular adalah penyakit yang disebabkan oleh transmisi agen infeksius tertentu atau produk beracun dari orang atau hewan yang terinfeksi ke host yang rentan baik secara langsung maupun tidak langsungDi negara maju akut pernafasan atas infeksi (ISPA) bertanggung jawab untuk banyak morbiditas dan cutiDi negara-negara berkembang penyakit menular masih merupakan penyebab utama kesakitan dan kematian baik

• Emerging deseas: yang tadinya tdak ada jadi ada (HIV, Flu burung• Reemerging : dulu ada lalu menurun sekarang meningkat lagi (TBC)

• There are emergence of new diseases e’g

- Lhasa fever (Viral disease, transmitted by rodent, first

recognized in Nigeria in 1969 )

- Legionnaires (Gram negative bacillus ,first described

after an outbreak of pneumonia following a meeting of

American Legionnaire in Philadelphia 1976. was traced

to the contamination of air-conditioning equipment.

- AIDS is the most devastating of the new communicable

disease.

• Ada munculnya penyakit baru e'g - Lhasa demam (virus penyakit, yang ditularkan oleh hewan pengerat, pertama diakui di Nigeria pada tahun 1969) - Legiuner (basil Gram negatif, pertama dijelaskan setelah wabah pnemonia menyusul pertemuan Amerika Legiuner di Philadelphia 1976. dijiplak untuk kontaminasi peralatan AC. - AIDS adalah yang paling buruk yang baru menular penyakit.

• Epidemic and endemic disease - Epidemic : is the occurrence in a community or region of a disease that is usually large and unexpected for the given place and time - Epidemic are usually either point source or contagious. - Endemic ; is one that is usually present in a given geographical area or population group at relatively high prevalence and incidence rate in

• Epidemi dan endemik penyakit- Wabah: adalah kejadian di masyarakat atau wilayah dari suatu penyakit yang biasanya besar dan tak terduga untuk tempat tertentu dan waktu- Epidemi biasanya baik titik sumber atau menular.- Endemik, adalah salah satu yang biasanya hadir dalam diberikan daerah geografis atau kelompok populasi relatif tinggi dan tingkat prevalensi kejadian di dibandingkan dengan daerah lain atau populasi

• Pandemik: suatu penyakit yang menyebar secara cepat shg mengenai sebagian dunia ; flu babi

comparison with other area or populations - Endemic disease become a major problems in developing countries .If condition changes either in host or the environment an endemic disease may become epidemic.• Spectrum of illness from communicable

disease in apparent infection mild disease se vere disease death

• - Penyakit endemik menjadi masalah utama di negara-negara berkembang. Jika kondisi perubahan baik dalam lingkungan host atau sebuah endemik penyakit bisa menjadi epidemi. Spektrum penyakit dari penyakit menular dalam infeksi penyakit ringan jelas se penyakit vere kematian

• KLB : - kejadian yang tadinya tdk ada jadi ada

- Angka kejadian naik 3 kali berturut-turut

- Angka kematian maupun kesakitan lebih dari 2 periode pada periode yang sama

• Chain of infection

-Communicable disease occur as a result of the interaction of the agent, the transmission process and the host. All of this are influence by

the environment.

-Knowledge of each factor in a chain of infection

maybe required before effective intervention can

take place

• Rantai infeksi Penyakit-Menular terjadi sebagai akibat interaksi antara agen, proses transmisi dan host. Semua ini dipengaruhi oleh lingkungan. -Pengetahuan setiap faktor dalam rantai infeksi mungkin diperlukan sebelum intervensi yang efektif dapat berlangsung

-The infection agent o .A large number of microorganism cause disease in human. .Infection is not equivalent to disease. Some infection do not produce clinical disease. .Pathogenicity ability of the agent to produce disease . Measure by the ratio of the number of person developing clinical illness to the number exposed to infection.

• Agen infeksi o . Sejumlah besar mikroorganisme penyebab penyakit pada manusia. . Infeksi tidak setara dengan penyakit. Beberapa infeksi tidak menghasilkan penyakit klinis. Patogenisitas . Kemampuan agen untuk menghasilkan penyakit. Mengukur dengan rasio jumlah orang mengembangkan penyakit klinis kepada nomor terkena infeksi.

.Virulence - a measure of severity of disease.

- can vary from low to high.

- virus attenuated and have low

virulence for immunizations

.Infectivity the ability of the agent to invade

and produce infection in the host

.Infection dose the amount required to cause

infection in susceptible subject

• virulensi. - Ukuran tingkat keparahan penyakit. - Dapat bervariasi dari rendah ke tinggi. - Virus dilemahkan dan rendah virulensi untuk imunisasi Infektivitas . Kemampuan agen untuk menyerang dan memproduksi infeksi dalam host Infeksi dosis. jumlah yang diperlukan untuk menyebabkan infeksi pada subjek rentan

.Reservoir the natural habitat of the

infectious agent, can be human

animal or environment source

.The source of infection is the person or

object from which the host

acquires the agent.

.Carrier infected person who shows no

evidence of clinical disease.

• Reservoir habitat alami agen menular, dapat menjadi manusia hewan atau lingkungan sumber Sumber infeksi. Orang atau objek dari yang tuan rumah mengakuisisi agen. Carrier orang. terinfeksi yang tidak menunjukkan bukti penyakit klinis

• Transmission

-is the spread of an agent

through the environment or to another

person.

-Transmission maybe direct or indirect.

• Transmisi -Adalah penyebaran agen melalui lingkungan atau ke orang. -Transmisi mungkin langsung atau tidak langsung.

• Direct transmission Indirect Tr---------------------------------------------------------------------------------------------

Touching Vehicle borne(food water

tool,etc

Kissing; Hepat Vector borne

Sexual intercourse :GO Airborne long distance

Other contact(breast feeding Parenteral

medical procedure etc)

Airborne short distance : TBC

Tranplacenta

Transfusion

Transmiter; agen nya tdk berkembang biak; lalat

• Host

The person or animal that provide a suit

able place for infectious agent to grow

and multiply under natural condition

-Reaction of the host to infection is

extremely variable,depend on interaction

of host, agent and transmission factor

• Tuan rumah Orang atau hewan yang menyediakan jas tempat untuk mampu tumbuh agen infeksius dan berkembang biak dalam kondisi alam -Reaksi dari host terhadap infeksi adalah sangat bervariasi, tergantung pada interaksi host, agen dan faktor transmisi

• Incubation period

-the time between entry of the infectious

and the appearance of first sign or symp-

tom of disease

- The outcome of infection is the degree of

natural or vaccine-induce resistance or

immunity of the host

• Masa inkubasi -Waktu antara masuknya menular dan munculnya tanda pertama atau symptom penyakitHasil infeksi adalah derajat alam atau vaksin-menginduksi ketahanan atau imunitas host

• Environment

- The environment plays a critical role in the development of communicable disease

- General sanitation, temperature, air pollution, water quality,

- Social economic like population density,

overcrowding, and poverty

• Lingkungan - Lingkungan memegang peranan penting dalam perkembangan penyakit menular - Umum sanitasi, temperatur, polusi udara, kualitas air, - Ekonomi sosial seperti kepadatan penduduk, berlebihan, dan kemiskinan

• Investigation and control C.D epidemic - Purpose of investigating epidemic is to identify its cause and the best mean to control it (pembasmian/penurunan insiden

penyakit smp tdk menjadi mslh kes bagi masy)

- Step : preliminary investigationio , Identifica-

tion of cases, collection and analyses data, implementation of control

Menurunkan kejadian penyakitinvestigasi (penyelidikan): identifikasi kasus (penyakit apa?), analisis

• Pemeriksaan dan kontrol epidemi C.D - Tujuan adalah untuk menyelidiki epidemi mengidentifikasi penyebabnya dan bermaksud terbaik mengendalikannya - Langkah: investigationio awal, Identifica- sanaan kasus, pengumpulan dan analisis data, pelaksanaan pengendalian

measure and follow up - preliminary verify D/ ,confirm epidemic + formulation of hypothesis - Surveillance is essential part of disease control (pengamatan penyakit terus-

menerus) - Sentinel health information system - Management of an epidemic treating cases ,preventing spread of the disease, and monitoring result of control measure

Survielan: pengamatan penyakit secara terus-menerussentinel:daerah khusus utk pengiriman data secara kontinyuData: 1. tepat waktu, 2. akurat, 3. lengkap

• mengukur dan tindak lanjut - Awal memverifikasi D /, pastikan + epidemi perumusan hipotesis - Surveilans adalah bagian penting dari penyakit kontrol - Sentinel sistem informasi kesehatan - Manajemen epidemi menangani kasus , Mencegah penyebaran penyakit, dan Hasil pemantauan tindakan kontrol

Wabah/KLB :1. commont source: sumbernya sama2. propegated: dari orang-ke orangefektifitas: tindakan kita sesuai dengan seharusnyaefisien: penggunanaan sumber daya minimal hasil maksimal

• Control measures can be directed against :

- source

- spread of infections.

- protecting people exposed to it.(• Once control measures has been implemented

surveillance must continue to ensure their acceptability and effectiveness.

systematic immunization program can be very effective in certain diseases

CLINICAL EPIDEMIOLOGY

• Definition is the application of epidemiological principal and methods to the practice of clinical medicine. (pasien yang menjadi sasaran)

• Clinical epidemiology is one of the basic medical sciences although in most medical schools this is not yet recognized.

• The central contents of clinical epidemiology are definition of normal and abnormal, accuracy of diagnostic test, natural history&prognosis of disease, effectiveness of Th/ and prevention in clinical practices.

• Definisi adalah aplikasi pokok epidemiologi dan metode untuk praktek kedokteran klinis. (Pasien Yang menjadi sasaran)

• epidemiologi klinis adalah salah satu ilmu kedokteran dasar meskipun di sekolah-sekolah medis yang paling ini belum diakui.

• Isi pusat epidemiologi klinis definisi normal dan abnormal, akurasi uji diagnostik, sejarah alam & prognosis penyakit, efektivitas Th / dan pencegahan dalam praktek klinis.

• Definition of normality and abnormality; The first priority in any clinical consultation is to determine whether the patient’s symptoms, sign and D/ test result are normal or abnormal. This

is necessary before further action can be taken whether this be investigation, treatment or observation. It would be easy if there were always clear distinction b/w frequency distribution of observation on normal and abnormal

• Definisi normalitas dan abnormalitas; Prioritas utama dalam konsultasi klinis adalah menentukan apakah pasien gejala, tanda dan D / hasil tes yang normal atau abnormal. Hal ini diperlukan sebelum tindakan lebih lanjut dapat diambil apakah ini menjadi penyelidikan, perawatan atau observasi. Ini akan mudah jika selalu ada perbedaan yang jelas b / w distribusi frekuensi observasi pada normal dan abnormal

• There are three types of criteria have been used to help clinician make practical decisions:

1. Normal as common Usually used in clinical practice is to consider frequency

occurring value as normal and those occurring infrequently as abnormal. The arbitrary cut off point on the frequency distribution ( mean +or-2 SD) as normal and beyond that as abnormal. This is called as operational definition of abnormality. If the distribution in fact Gaussian (statistical normal) cut-off point =2,5% of the populatio

is abnormal. As alternative approach 95% of population is normal and 5%of

population as Abnormal

• Ada tiga jenis kriteria telah digunakan untuk membantu dokter membuat keputusan praktis: 1. Normal seperti biasa Biasa digunakan dalam praktek klinis adalah mempertimbangkan frekuensi nilai terjadi seperti biasa dan jarang terjadi tersebut sebagai abnormal. Cut off point sewenang-wenang terhadap distribusi frekuensi (berarti + atau-2 SD) seperti biasa dan lebih dari itu sebagai abnormal. Hal ini disebut sebagai definisi operasional kelainan. Jika distribusi Gaussian sebenarnya (statistik normal) titik cut-off = 2,5% dari populatio yang tidak normal. Sebagai pendekatan alternatif 95% dari populasi adalah normal dan 5% dari penduduk sebagai Abnormal

2, Abnormality associated w/ disease

based on the distribution s for both healthy and diseased people and attempts to define a cut-of points that clearly separate the two groups ,A comparison of two frequency distributions often shows considerable overlaps .Choosing a cut-off point that nearly separate s cases from non cases is clearly impossible. there are always some healthy people on the abnormal side of the cut-off point and some true cases on the normal side.

3 Abnormal as treatable’

The difficulties in distinguishing b/w normal and

.

2, Abnormalitas terkait w / penyakit berdasarkan distribusi s baik untuk orang sehat dan sakit dan upaya untuk mendefinisikan cut-titik yang jelas memisahkan dua kelompok, A perbandingan dua distribusi frekuensi yang cukup sering menunjukkan tumpang tindih. Memilih titik cut-off yang hampir terpisah s kasus dari kasus yang tidak jelas tidak mungkin. selalu ada beberapa orang yang sehat di sisi abnormal titik cut-off dan beberapa kasus yang benar di samping yang normal.Abnormal sebagai diobati ‘

3. Kesulitan dalam membedakan b / w normal dan

abnormal using the above criteria led to the use of

criteria determined by evidence from randomized

controlled trials, which indicate the level at which T/

does more good than harm. Unfortunately this

information is only rarely available in clinical

practice. The example of this is treatment of hyper-

tension. Treating patient with high diastolic pressure

(>120mmHg) was beneficial . 95 mmHg is cut-off

point whether treated or not

normal dengan menggunakan kriteria di atas menyebabkan penggunaan kriteria yang ditetapkan oleh bukti dari acak dikontrol percobaan, yang menunjukkan tingkat di mana T / tidak lebih baik dari bahaya. Sayangnya ini informasi hanya jarang tersedia di klinis praktek. Contoh dari hal ini adalah pengobatan hiper- ketegangan. Memperlakukan pasien dengan tekanan diastolik tinggi (> 120mmHg) adalah menguntungkan. 95 mmHg adalah cut-off titik apakah dirawat atau tidak

Treatment of hypertension ;changing criteria overtime

• pharmacological T/ introduced (125)

• veteran administration trial• (110/100)

• Australian trial (100)

• T/ not recommended US trial (90)

• 1955 1965 1975 1985

• Diagnostic test

-first objective in a clinical sitution is to

diagnose any treatable disease present.

-diagnostic test will help that,

-usualy involve laboratory investigation microbiological,biochemical, physiologi

cal, anatomical.etc

• Uji diagnostik Tujuan pertama dalam sitution klinis adalah mendiagnosa semua penyakit ini bisa diobati. tes diagnostik akan membantu itu, -Usualy melibatkan penyelidikan laboratorium mikrobiologi, biokimia, physiologi kal, anatomical.etc

• Value of the test

a disease maybe either present or absent

and the test maybe pos or negative/

Relationship B/w diagnostic test result and the occurrence of disease

• Nilai ujian penyakit yang mungkin baik ada atau tidak ada dan pengujian mungkin pos atau negatif / Hubungan B / w hasil uji diagnostik dan terjadinya penyakit

hapalkan

• disease

present absent

pos true pos false pos

Test

neg false neg true neg

sensitivity? Specificity ?

pos predictive value? Neg predictive value ?

• Natural history and prognosis;

• Effectiveness of treatment

• Prevention in clinical practice

matrIKULASI

Documents

low income countries

case control studies

incidence rate

simple

risk assesment

natural history

systematic error

1959 doll