Welcome! Overweight / obesity prevention, treatment, and maintenance from childhood to adulthood: Discussing review-level evidence You will be placed on hold until the webinar begins. The webinar will begin shortly, please remain on the line.
Welcome! Overweight / obesity prevention, treatment, and
maintenance from childhood to adulthood:
Discussing review-level evidence
You will be placed on hold until the webinar begins. The webinar will begin shortly, please remain on the
line.
Review-level evidence series:1. Peirson, L., Fitzpatrick-Lewis, D., Morrison, K., Ciliska, D., Kenny, M., Ali, M. U., et
al. (2015).Prevention of overweight and obesity in children and youth: A systematic review and meta-analysis. CMAJ Open, 3(1), E23-E33.(2)
2. Peirson L., Fitzpatrick-Lewis D., Morrison K., Warren R., Ali M.U., & Raina P. (2015).Treatment of overweight and obesity in children and youth: a systematic review and meta-analysis. CMAJ Open, 3(1), E35-E46.(2)
3. Peirson, L., Douketis, J., Ciliska, D., Fitzpatrick-Lewis, D., Ali, M. U., & Raina, P. (2014).Prevention of overweight and obesity in adult populations: A systematic review. CMAJ Open, 2(4), E268-E272.(2)
4. Peirson, L., Douketis, J., Ciliska, D., Fitzpatrick-Lewis, D., Ali, M. U., & Raina, P. (2014).Treatment for overweight and obesity in adult populations: a systematic review and meta-analysis. CMAJ Open, 2(4), E306-E317.(2)
5. Peirson, L., Fitzpatrick-Lewis,D., Ciliska, D., Ali, M. U., Raina, P., & Sherifali, D. (2015).Strategies for weight maintenance in adult populations treated for overweight and obesity: a systematic review and meta-analysis. CMAJ Open, 3(1), E47-E54.(2)
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The Health Evidence Team
Maureen Dobbins Scientific Director
Heather HussonManager
Susannah WatsonProject Coordinator
Robyn TraynorPublications Consultant
Students:Emily Belita(PhD candidate)
Jennifer YostAssistant Professor
Olivia MarquezResearch Coordinator
Kristin ReadResearch Coordinator
Yaso GowrinathanInformation Liaison
Emily SullyResearch Assistant
Bethel WoldemichaelResearch Assistant
Liz KamlerResearch Assistant
Zhi (Vivian) ChenResearch Assistant
What is www.healthevidence.org?
Evidence
Decision Making
inform
Why use www.healthevidence.org?
1. Saves you time2. Relevant & current evidence 3. Transparent process4. Supports for EIDM available 5. Easy to use
A Model for Evidence-Informed Decision
Making
National Collaborating Centre for Methods and Tools. (revised 2012). A Model for Evidence-Informed Decision-Making in Public Health (Fact Sheet). [http://www.nccmt.ca/pubs/FactSheet_EIDM_EN_WEB.pdf]
Stages in the process of Evidence-Informed Public Health
National Collaborating Centre for Methods and Tools. Evidence-Informed Public Health. [http://www.nccmt.ca/eiph/index-eng.html]
Poll Question #2
Have you heard of PICO(S) before?
1.Yes2.No
Searchable Questions Think “PICOS”
1. Population (situation)
2. Intervention (exposure)
3. Comparison (other group)
4. Outcomes
5. Setting
How often do you use Systematic Reviews to inform a program/services?
A.AlwaysB.OftenC.SometimesD.NeverE.I don’t know what a systematic review is
Poll Question #3
Dr. Leslea Peirson , Ph.D, is a Review Coordinator at McMaster Evidence Review and Synthesis Centre.
Leslea Peirson
Review Series: • Child Prevention
Prevention of overweight and obesity in children and youth: A systematic review and meta-analysis
• Child ManagementTreatment of overweight and obesity in children and youth: A systematic review and meta-analysis
• Adult PreventionPrevention of overweight and obesity in adult populations: A systematic review
• Adult ManagementTreatment for overweight and obesity in adult populations: A systematic review and meta-analysis
• Adult Maintenance Strategies for weight maintenance in adult populations treated for overweight and obesity: A systematic review and meta-analysis
Review Topics and Questions
5 REVIEW TOPICSPrevention of
Overweight/ObesityManagement of
Overweight/ObesityMaintenance of
Weight Loss
Children/Youth Adults
KEY QUESTIONS: What are the benefits and harms of behavioural and/or pharmacological interventions
What Counts as Evidence
P POPULATIONS
I INTERVENTIONS
CDCOMPARATORSDESIGNS
OTOUTCOMESTIMEFRAMES
S SETTINGS
Populations
Review Topics
Child Prevention
Child Management
Adult Prevention
AdultManagement
Adult Maintenance
Populations
0-18 years
normal weightaccepted mixed
weight that included some normal weight
2-18 years
BMI >85th centile
18+ years
BMI ≥18.5 <25accepted mixed
weight that included some normal weight
18+ years
BMI ≥25 <40
18+ years
lost weight in Rx
Interventions
Review Topics
Child Prevention
ChildManagement
Adult Prevention
AdultManagement
Adult Maintenance
Interventions
behavioural diet, exercise, lifestyle
behavioural diet, exercise, lifestyle
and/or
pharmacologic orlistat
behavioural diet, exercise, lifestyle
and/or
complementary or alternative
behavioural diet, exercise, lifestyle
and/or
pharmacologic orlistat, metformin
behavioural diet, exercise, lifestyle
and/or
pharmacologic orlistat, metformin
ComparatorsDesigns
Review Topics
Child Prevention
ChildManagement
Adult Prevention
AdultManagement
Adult Maintenance
ComparatorsDesigns
Benefits: RCTs with a usual care, no intervention or minimal intervention control group
Harms: any study design with any type of comparator or no control group
OutcomesTimeframe
Review Topics
Child Prevention
ChildManagement
Adult Prevention
AdultManagement
Adult Maintenance
OutcomesTimeframes
change in BMI, BMIz, prevalence
overweight/obesity (≥12w post-baseline)
change in BMI, BMIz, prevalence
overweight/obesity (≥6m post-baseline)
change in kg, BMI, waist
circumference, body fat %
(≥12m post-baseline)
change in kg, BMI, waist
circumference; 5% or 10% loss (≥12m post-baseline)
maintenance of weight loss: kg, BMI, waist circ.,
5%, 10% (longest available)
change in lipids, BP, QOL, fitness(≥12w post-baseline)
change in lipids, BP, glucose, QOL,
fitness (≥6m post-baseline)
change in lipids, BP, glucose;
incidence T2D (≥12m post-baseline)
change in lipids, BP, glucose;
incidence T2D (≥12m post-baseline)
disordered eating, distress, micronutrient
deficits, abnormal growth
(any time)
adverse events (any, serious, GI,
study withdrawal)
(any time)
labelling, disordered
eating, distress, stigma,
nutritional deficits, cost
(any time)
adverse events(any, serious, GI,
study withdrawal)
(any time)
Settings
Review Topics
Child Prevention
ChildManagement
Adult Prevention
AdultManagement
Adult Maintenance
Settingsconducted in, feasible for or referable from primary care
(child prevention included interventions conducted in education settings)
Search and Selection Review Topics
Prevention of Overweight/Obesity
Management of Overweight/Obesity
Maintenance of Weight Loss
Children/Youth
updated Cochrane 2011 search7,318 citations; 468 full-text
updated USPSTF 2010 search2,731 citations; 333 full-text
included 90 studies (123 papers)
included 31 studies (37 papers)
no studies targeted only normal weight; all studies
included mixed weight samples
Adults
de novo search (1980→)31,989 citations; 1,191 full-text
updated USPSTF 2011 search3,584 citations; 358 full-text
updated USPSTF 2011 search15,309 citations; 1,549 full-text
included 26 studies (48 papers) included 68 studies (117 papers)
included 8 studies (11 papers)
1 study targeted only normal weight; 25 studies included
mixed weight samples
AnalysesRisk of bias assessments for individual studies and across studies (bodies of evidence) available for each outcome
Meta-analyses if possible to pool data (produces forest plots) with sub-group analyses on pre-defined categories (varied by review):
• focus of intervention (behavioural, pharmacological + behavioural)• type of behavioural intervention (diet, exercise, diet + exercise, lifestyle)• intervention setting (non-education, education only, education plus other)• duration of intervention (≤12 months, >12 months)• age group (0-5 years, 6-12 years, 13-18 years)• sex• baseline CVD risk status (high risk, low risk/not specified)• study risk of bias rating (high, unclear, low)
GRADE assessments of the quality of the evidence
Risk of Bias Table Example*
*From Adult Management Review
Meta-analysis Example*
*From Adult Management Review
Assessing Quality of the Evidence: GRADEWe assess the body of evidence available for each outcome using the GRADE (Grading of Recommendations, Assessment, Development & Evaluation) system For each body of evidence we make assessments across 5 domains
These evaluations result in one of 4 quality ratings that reflects the degree of confidence that the available evidence correctly reflects the theoretical true effect of the intervention, service or practice
Each body of evidence begins with a high rating which is downgraded one level for every domain judged to have serious concerns (2 levels if concerns are very serious)
Risk of Bias Consistency Directness Precision Reporting BiasAny methodological limitations or flaws?
How much variation between studies
(direction and size of estimates)?
How well does it match the PICO
statement?
Enough participants or events? How wide is
the confidence interval?
Any indications of publication bias?
High Moderate Low Very Lowtrue effect lies close to
estimate; further research unlikely to change this
true effect lies close to estimate but possibility it is
substantially different; further research may change
estimate
true effect may be substantially different from estimate; further
research very likely to have important impact on confidence
and to change estimate
estimate of effect is very uncertain; further research
very likely to have important impact on confidence and to
change estimate
GRADE Table Example*GRADE Evidence Profile Table: Effect of Management Interventions on Loss of ≥5% Baseline Body Weight
Quality Assessment No. of Participants Effect
GRADEQuality
ImportanceNo. of Studies
DesignRisk of
BiasInconsistency Indirectness Imprecision Other Treatment Control
Relative(95% CI)
Absolute per Million (Range)
ARRNNT
(95% CI)
≥5% Weight Loss: Overall
24randomized
trials1
serious risk2
no serious inconsistency3
no serious indirectness4
no serious imprecision5
reporting bias6
2,506/5,498 (45.5802%)
1,149/4,359 (26.3593%)
RR 1.7745 (1.5813 to
1.9915)
204,152 more (from 153,226 to 261,352 more)
20.42%5
(4, 7)LOW CRITICAL
≥5% Weight Loss: by Primary Focus of Intervention – Behavioural
11randomized
trials7
serious risk8
no serious inconsistency9
no serious indirectness10
no serious imprecision11
reporting bias12
431/1,615 (26.6873%)
190/1,226 (15.4976%)
RR 1.7532 (1.3520 to
2.2734)
116,728 more (from 54,551 to 197,346 more)
11.67%9
(5, 18)LOW CRITICAL
≥5% Weight Loss: by Primary Focus of Intervention – Pharmacological plus Behavioural
13randomized
trials13
serious risk14
no serious inconsistency15
no serious indirectness16
no serious imprecision17
reporting bias18
2,075/3,883 (53.4381%)
959/3,133 (30.6096%)
RR 1.7926 (1.5715 to
2.0447)
242,612 more (from 174,934 to 319,779 more)
24.26%4
(3, 6)LOW CRITICAL
In reviews these tables are followed by detailed footnotes that elaborate on the ratings
*From Adult Management Review
Selected Key Findings*: Children
Child Prevention Child Management
Significant benefits for lowered BMI/BMIzSMD -0.07 (-0.10, -0.03) VLSignificant reduction in prevalence ov/obRR 0.94 (0.89, 0.99) VL
Significant benefits for lowered BMI/BMIzSMD -0.53 (-0.69, -0.36) M
Significantly greater benefits forHDL: MD 0.07 (0.04, 0.10) LPF: SMD 0.32 (0.14, 0.50) L
Significantly greater declines/benefits forSBP: MD -3.42 (-6.65, -0.29) MDBP: MD -3.39 (-5.17, -1.60) MQOL:MD 2.10 (0.60, 3.60) M
Few studies reported data for AE; those that did reported no AE or mostly mild/moderate AE
GI difficulties more common in youth taking orlistatRR 3.77 (2.56, 5.55) M
*Results are for intervention group as compared to control group GRADE ratings: moderate=M, low=L, very low=VL; SMD=standardized mean difference, MD=mean difference, RR=risk ratio, BMI=body mass index (kg/m 2), BMIz=BMI z-score, ov/ob=overweight/obesity, WC=waist circumference (cm), 5%=loss of ≥5% initial body weight, 10%=loss of ≥10% initial body weight, BF%=body fat %, TC=total cholesterol (mmol/l), LDL=low-density lipoproteins (mmol/l), HDL=high-density lipoproteins (mmol/l), FG=fasting blood glucose (mmol/l), T2D=type 2 diabetes (incidence), SBP=systolic blood pressure (mmHg), DBP=diastolic blood pressure (mmHg), PF=physical fitness (stages or laps 20m shuttle run), QOL=(overall) quality of life, AE=adverse event GI=gastrointestinal
Selected Key Findings*: Adults
Adult Prevention AdultManagement Adult Maintenance
Significantly greater reductions/benefits forKG: MD -0.73 (-0.93 , -0.54) VLBMI: MD -0.24 (-0.34, -0.15) L WC: MD -0.95 (-1.27, -0.63) VLBF%: MD -1.27 (-1.93, -0.61) L
Significantly greater reductions/benefits forKG: MD -3.02 (-3.52, -2.52) MBMI: MD -1.11 (-1.39, -0.84) MWC: MD -2.78 (-3.34, -2.22) M5%: RR 1.77 (1.58, 1.99) L10%: RR 1.91 (1.69, 2.16) L
Significantly less regain, better maintenanceKG: MD -1.44 (-2.42, -0.47) MBMI: MD -0.95 (-1.67, -0.23) MWC: MD -2.30 (-3.45, -1.15) M5%: RR 1.33 (1.15, 1.54) M
Significantly greater declines inTC: MD -0.06 (-0.11, -0.01) LLDL: MD -0.06 (-0.09, -0.03) LFG: MD -0.04 (-0.08, -0.002) LDBP: MD -0.18 (-0.44, -0.07) VL
Significantly greater declines inTC: MD -0.21 (-0.29, -0.13) MLDL: MD -0.21 (-0.29, -0.12) LFG: MD -0.26 (-0.38, -0.13) MSBP: MD -1.70 (-2.23, -1.17) MDBP: MD -1.42 (-1.88, -0.96) MT2D: RR 0.62 (0.50, 0.77) M
No studies with data on AE of interest
Very few and minor AE for behavioural; GI difficulties more common for drugsRR 1.58 (1.47-1.70) L
*Results are for intervention group as compared to control group GRADE ratings: moderate=M, low=L, very low=VL; SMD=standardized mean difference, MD=mean difference, RR=risk ratio, BMI=body mass index (kg/m 2), BMIz=BMI z-score, ov/ob=overweight/obesity, WC=waist circumference (cm), 5%=loss of ≥5% initial body weight, 10%=loss of ≥10% initial body weight, BF%=body fat %, TC=total cholesterol (mmol/l), LDL=low-density lipoproteins (mmol/l), HDL=high-density lipoproteins (mmol/l), FG=fasting blood glucose (mmol/l), T2D=type 2 diabetes (incidence), SBP=systolic blood pressure (mmHg), DBP=diastolic blood pressure (mmHg), PF=physical fitness (stages or laps 20m shuttle run), QOL=(overall) quality of life, AE=adverse event GI=gastrointestinal
Contextual Questions• Differential findings for sub-groups (e.g.,
ethnicity, age, rural and remote populations, SES)?
• Resource implications and cost-effectiveness• Patients’ and practitioners’ values and
preferences• Risk assessment tools
Poll Question #4Do you agree with the findings of this review series?A.Strongly agreeB.AgreeC.NeutralD.DisagreeE.Strongly disagree
Questions?
A Model for Evidence-Informed Decision
Making
National Collaborating Centre for Methods and Tools. (revised 2012). A Model for Evidence-Informed Decision-Making in Public Health (Fact Sheet). [http://www.nccmt.ca/pubs/FactSheet_EIDM_EN_WEB.pdf]
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