1. Introduction to epidemiological study designs

KNOWLEDGE FOR THE BENEFIT OF HUMANITYKNOWLEDGE FOR THE BENEFIT OF HUMANITY

PUBLIC HEALTH AND EPIDEMIOLOGY (HFS3063) Epidemiological Study Designs:

INTRODUCTION

Dr. Dr. MohdMohd RazifRazif ShahrilShahril

School of Nutrition & Dietetics School of Nutrition & Dietetics

Faculty of Health SciencesFaculty of Health Sciences

UniversitiUniversiti Sultan Sultan ZainalZainal AbidinAbidin

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Topic Learning Outcomes

By the end of this lecture, students should be able to;

• Identify basic study designs used in epidemiology studies.

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Study designs direct how the investigation is

conducted

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4 Fig 1: Study designs

Time frame of studies • Prospective Study - looks forward, looks to the future,

examines future events, follows a condition, concern or

disease into the future

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time

Study begins here

With a prospective study one starts with cohorts of well individuals, and

we wait until events occurs.

(cont.) Time frame of studies • Retrospective Study - “to look back”, looks back in

time to study events that have already occurred

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time

Study begins here

Looking backward is often difficult because of recall bias, however, the case control studies are very inexpensive in

comparison with prospective studies

Study design sequence

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Case reports Case series Descriptive

epidemiology

Analytic epidemiology

Clinical trials

Animal Animal study

Lab study

Cohort Case- Case- control

Cross-

Cross- sectional

Hypothesis formation Hypothesis formation

Hypothesis testing Hypothesis testing

Increasing knowledge of exposure

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Descriptive Studies

Case-control Studies

Cohort Studies

Develop hypothesis

Investigate it’s relationship to outcomes

Define it’s meaning with exposures

Clinical trials Test link experimentally

Thank YouThank You

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