1

Paul J. Veugelers & Angela L. FitzgeraldAmerican Journal of Public Health

Mar 2005; Vol. 95, No. 03

Title:Title:““Effectiveness of School Programs Effectiveness of School Programs in Preventing Childhood Obesity: in Preventing Childhood Obesity:

A Multilevel ComparisonA Multilevel Comparison.” .”

1

Research Seminar: PresentationResearch Seminar: Presentation

Presentation by,

Asif Raza KhowajaJanuary 30th, 2010

2

RationaleRationale

To highlight major public health crisis of pandemic increase in childhood obesity. To emphasize potential health problem of developing countries. Childhood obesity is preventable, therefore, proactive policies can be formed at Govt. / Local level. Focusing health promotion through “School Health”. Renowned Journal & subject relevant publication

2

3

Over past four decades, childhood obesity has remarkably increased in U.S, Canada, Australia & Europe

Childhood obesity is major cause of Hypertension, type 2 Diabetes, Cardiovascular diseases and Cancer problems which account for billions of dollars in healthcare spending

School health initiatives have excellent impact on preventing childhood obesity, however, effectiveness of such programs varies across countries.

BackgroundBackground

3

4

5

6

IntroductionIntroduction

Define Childhood obesity:Define Childhood obesity:

The measurement of overweight and obesity in children is difficult due to maturation & growth rate. There has been recent international agreement on the need to use BMI to define obesity in children. Children / Youth having BMI 25-30 are overweight and BMI >30 are obese.

BMI: Body Mass Index is a composition of body mass, calculated as weight in Kg divided by square of height in meters

4

7

Factors of Childhood ObesityFactors of Childhood Obesity

5

8

IntroductionIntroduction

Insufficient physical activity and poor nutrition due to the consumption of calorie-dense foods are acknowledged as primary factors of childhood excess body weight.

Physical activity and nutrition in School are primary foci of health promotion initiatives to prevent or reduce childhood obesity.

The Centers for Disease Control and Prevention (CDC) provides guidelines for school programs to promote physical activity and healthy eating.

Continued…Continued…

6

9

CDC Guidelines CDC Guidelines Healthy Eating & Activity Healthy Eating & Activity

in Schoolsin Schools

School Health Policies

Curriculum

Integration of food serv.

Nutrition Education

Family involvement

Staff /Teachers training

IntroductionIntroduction Continued…Continued…

7

10

ObjectivesObjectives

To evaluate the effectiveness of school programs in regard to:

Prevent Overweight

& Obesity

Increase Physical Activity

ImproveDietary Quality

8

11

MethodologyMethodology

Design Design :: Population-based survey Setting Setting :: Homogenous Canadian

province of Nova Scotia, where more than 95% of elementary school children attend similarly public funded schools .

ParticipantsParticipants:: Enrolled 5517 children (5th grade school children)

9

12

Inclusion criteria:Children of 5th grade in school.Schools and Parents who voluntarily consented.Resident of Canadian Province Nova Scotia.

MethodologyMethodology Continued…Continued…

10

13

(Comprising of School Prevention Program)School Children of 5th grade

Children’s Lifestyle & School Performance Study (CLASS)

291 Public Schools

Invited

282 Public Schools

Consented

(96.9%) (51.1%)

MethodologyMethodology

5517 students participated after Parents’ Consent

73 SchoolsWith Nutrition

Program

07 SchoolsWith AVHPSP

Program

199 SchoolsWithout Nutrition

Program

2003 Survey

279 Public Schools

Completed survey

(99.9%)

Continued…Continued…

11

14

Harvard Youth AdolescentFood Frequency Questionnaire

Questionnaire

Frequency & Kindsof Food

Number of daily servings of fruits and vegetables

Nutrients & Calorie Intake

Percentage of calorie intake from

dietary fats

Overall DietaryQuality

Dietary adequacy,variety, moderation

& balance

5200 Completed5200 Completed(94%) (94%)

MethodologyMethodology

Data Data Collection:Collection:

5517 Consented 5517 Consented

Continued…Continued…

12

15

Physical & Sedentary Activities

Assessment

Physical Activity Reported weekly number of engagements in organized

sports and leisure time Physical activity.

Sedentary Activity Reported daily number of hours watching television,

Using computer, and Playing video games.

5197 Completed5197 Completed(94%) (94%)

MethodologyMethodology

5517 Consented 5517 Consented

Data Collection:Data Collection:

Continued…Continued…

13

16

Overweight & Obesity

Assessment

Overweight The international body mass

index cutoff points (more than 25 Kg/m2 ).

Adjusted for age & gender

Obesity

The international body massindex cutoff points

(more than 30 Kg/m2 ). Adjusted for age & gender

4298 Completed4298 Completed(78%) (78%)

MethodologyMethodology

5517 Consented 5517 Consented

Data Collection:Data Collection:

Continued…Continued…

14

17

Statistical AnalysisStatistical Analysis

Descriptive :Descriptive : Proportions

Inferential :Inferential : Multi-level Logistic Regression Method Beta Co-efficient Odds ratio 95 % Confidence Interval

15

18

ResultsResults

5200 Children5200 ChildrenCompleted YAQ Completed YAQ

3656 (70.3%)Without

Nutrition Program

1350 (26%)With

Nutrition Program

133 (2.6%)With

AVHPSP Program

16

19

Results Results Continued…Continued…

20

ResultsResults

Summary of Summary of Table 1Table 1 Students in AVHPSP exhibit lower rates

of overweight, obesity and have better dietary habits (higher consumption of fruits & vegetables, less caloric intake from fat) and higher dietary quality index score. Students in AVHPSP reported more participation in physical activities and less participation in sedentary activities. The characteristics of students from school without a nutrition program and with a nutrition program (other than the AVHPSP) were almost similar.

Continued…Continued…

18

21

Results Results

Non- significant

Significant

Continued…Continued…

22

Results

Rates of overweight & obesity are significantly lower among students in schools having AVHPSP than schools without nutrition program Students in AVHPSP reported more consumption of fruits and vegetables & better dietary quality. (Statistically Significant findings).

Fats consumption is low among students in AVHPSP. But (Statistically Non-significant findings). Students in AVHPSP reported more participation in physical activity & less in sedentary activities. But (Statistically Non-significant findings).

Summary of Summary of Table 2Table 2

Continued…Continued…

20

23

Discussion Discussion

School-based healthy eating & physical activity programs provide greater opportunity to:

Enhance learning & provide social benefits Enhance health during critical periods of growth Lower risk for chronic diseases in adulthood Help to establish health behaviors at an early age.

Author contends that limited number of studies have been conducted on “Effectiveness of school programs to prevent childhood obesity” and results of such studies are inconsistence.

21

24

Discussion Discussion

This study demonstrate effectiveness of some programs and the absence of effectiveness of others.

It creates evidence that schools with a program like AVHPSP, are consistence with the CDC recommendations for school-based healthy eating program.

Diet & activities were similar among students from schools with and without nutrition program, because:

Recently introduced School Nutritional Programs Masking of possible benefits in schools Without Nutrition

Program.

Continued…Continued…

22

25

Strengths & Strengths & LimitationLimitation (by author)

High response rate & Adjustment for Non-response bias & potential confounders.

Use of measurement (Ht. & Wt.) to define overweight & obesity, prevent self-report bias.

Using validated modified YAQ questionnaire

Exactness of adjustment is difficult to verify. Cannot exclude confounding of factors that were not considered. Self reporting of YAQ questions are subject to error.

23

26

Conclusion Conclusion

As a result of rapid recent increase in childhood obesity, prevention is a public health priority.

Broader implementation & investment in school programs preventing childhood obesity is justified, because, it has high potential to reduce childhood obesity and in the long term, reduce likelihood of comorbid conditions and health care spending.

24

27

Critique (by presenter)_ Critique (by presenter)_

Title:Title:The concept of effectiveness of

school programs in preventing childhood obesity is well discussed in the paper.

The title itself seems catchy, reflecting the notion of health promotion, focusing School Health .

Authors affiliation:Authors affiliation:Both authors belong to Dept. of

Community Health & Epidemiology Dalhousie University, Nova Scotia.

25

28

CritiqueCritique

Abstract:Abstract:Well structured Provides comprehensive information

about the study.

Funding:Funding:Canadian Population Health funds (Principal author won new investigator

award)

Continued…Continued…

26

29

Introduction: Introduction:

Justifies the need for such study. Thoroughly discussed all objectives of the study. Presents guidelines of CDC & relate with study objectives. The definition for “Childhood obesity” is required. The reason for targeting 5th grade school children not mentioned.

CritiqueCritique Continued…Continued…

27

30

Critique: MethodologyCritique: Methodology

Ethical Consideration:Ethical Consideration:Approval of Human Participant

Protection was taken from Human Research Board, Dalhousie University Nova Scotia.

Informed consent was taken from parents before the participation of their children.

Continued…Continued…

28

31

Validity: Internal ValidityValidity: Internal Validity(A). Questionnaire & Physical (A). Questionnaire & Physical Measurement Measurement

Using validated tools for data collection is appreciated.Highlight high response rate in questionnaire completion, however, very poor response rate (51.1%) of parental consent on school level. After parental consent, School children 317 (7%) not completed YAQ and 320 (6%) not completed Physical & Sedentary activity questionnaire, the reason for such non-completion not stated.

Critique: MethodologyCritique: Methodology Continued…Continued…

29

32

Validity: Internal ValidityValidity: Internal Validity (A). Questionnaire & Physical (A). Questionnaire & Physical Measurements.Measurements.

Provided good reference of international cut-off points for obesity & overweight.

But fail to relate weight with standard cut-off for height.

How many representatives involved for data collection, their qualification, additional specific trainings , not stated.

Standardization of instruments used for height & weight, not stated.

The minimally required sample size not calculated / justified.

Critique: MethodologyCritique: Methodology Continued…Continued…

30

33

Validity: External ValidityValidity: External Validity (B). Generalizability:(B). Generalizability:

Results are worth to generalize because of:

Rigor of research methodology Reducing chance / bias Considerably large sample size.

Critique: MethodologyCritique: Methodology Continued…Continued…

31

34

The results tables are simple to understand.

Use of sophisticated statistical analysis is appreciated.

Presents study analysis adjusted for gender, area of residence (urban & rural), parental education, & income.

Reduce the likelihood of Chance / Bias by controlling the effects of possible confounders on the findings.

Critique: ResultCritique: Result Continued…Continued…

32

35

Discussion: Discussion:

Language is easy to understand.Study strengths & limitations

highlighted.

• Bibliography: Bibliography: Considerable review of recent literature

has been done.

CritiqueCritique Continued…Continued…

33

36

Policy Implication Policy Implication

Health-care workers and pediatricians should screen children for obesity and risk factors as part of "well-child" visits.

Health workers should provide counseling and educational information, and prescribe healthy diets and exercise for children.

In order to prevent potential health In order to prevent potential health problem of childhood obesity in problem of childhood obesity in developing countries, the National developing countries, the National Health Policies need to be proactive in Health Policies need to be proactive in developing policies adhering to the developing policies adhering to the health needs of children at state level. health needs of children at state level.

34

37

Making school health program as an integral part of school academia. Adapting and following the guidelines of CDC in school-based healthy eating programs. Parents and other family members should act as positive role models, decreasing their own and the children's sedentary activities and planning more family activities. The community in general should improve safety and encourage neighborhood designs to facilitate walking, biking and outdoor play.

Policy Implication Policy Implication Continued…Continued…

35

38

39

Thank youThank you