childhood obesity in hays cisd: changes from 2010 – 2017 · students in both elementary and...
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Childhood Obesity in Hays CISD: Changes from 2010 – 2017
Leigh Ann Ganzar, MPHSusan Millea, PhD
Presentation to HCISD School Health Advisory CommitteeAugust 14, 2018
Partnership to Promote Child Health
Two studies conducted at no cost to HCISD addressing Child Obesity
Study 1:Elementary, Middle, High School Students as a group, over time
Study 2:Comparing students to themselves over time
Hays CISD Multi-year Child Obesity Study
Background• Childhood obesity is a significant public health problem:
– Increases risk for cardiovascular disease and Type II diabetes– Has negative mental health consequences in children– Increases risk for obesity in adulthood 1
• Body mass index (BMI) is a valuable measure to assess changes in overweight and obesity over time in children 2– Overweight is defined as having a BMI greater than or equal to the 85th
percentile and below the 95th percentile– Obesity: BMI is greater than or equal to the 95th percentile for children and
adolescents of the same age and sex 3
• Nearly 1 in 5 school age children and young people (6 to 19 years) in the United States has obesity– Ethnic minority children having higher rates of obesity compared to non-
Hispanic white children 4
• Schools can serve as an important context for health promotion and obesity prevention, especially the presence of environmental and non-curricular components, including the policies and practices around healthy behavior promotion 5
Hays CISD Multi-year Child Obesity Study
STUDY 1: ELEMENTARY, MIDDLE, HIGH SCHOOL STUDENTS AS A GROUP, OVER TIME
Hays CISD Multi-year Child Obesity Study
Purpose
As a follow up to the 2010-2011 school year collaboration between Hays CISD and Children’s Optimal Health, the purpose of this project was to assess changes in overweight and obesity in Hays CISD students over time.
This study looked at SY 2014-15 and SY 2016-17.
Hays CISD Multi-year Child Obesity Study
MethodsData Sources• FITNESSGRAM assessments 2010-2011, 2014-2015, and 2016-2017 school
years. – BMI calculated using CDC growth charts for height, weight, age, and sex 6
• Texas Education Agency’s PEIMS were used for the demographic characteristics including sex, age, race/ethnicity, and economic disadvantage as measured by eligibility for free or reduced lunch 7
Statistical Methods• This study used complete case analysis, only records with complete BMI
data. • Descriptive statistics including means and proportions. Pearson chi square
tests were used to detect differences in overweight and obesity between years, and the level for statistical significance was set to p<.05 for all analyses.
Hays CISD Multi-year Child Obesity Study
MethodsMapping Methods• ArcMap 10.5 was used to create all maps (ESRI, 2016). • To meet privacy-protection of individuals’ data, residence
location latitude and longitude values were randomly shifted anywhere from 100 to 300 feet; aggregated data is presented.
• Choropleth maps used the U.S. Census Tract Block Groups from the 2010 Census (released in 2014). – The student level data was aggregated to the block group level. – Quantile breaks were used for the BMI, economic disadvantage, and
race/ethnicity choropleth maps, adjusted to the nearest whole number, to ensure comparability across years and ethnicities.
– Due to low proportions of Black/African American and other racial/ethnic groups in the district, only Hispanic and non-Hispanic White student populations were mapped
Hays CISD Multi-year Child Obesity Study
Results - Demographics2010 – 2011
n= 8,1872014 – 2015
n= 7,7832016 – 2017
n=7,752
p value for difference between
yearsSex (%)
Male 51.5 50.2 52.0 0.059
Female 48.5 49.8 48.0
Ethnicity (%)
Hispanic 59.9 63.6 62.8 <0.001***
White 34.6 30.5 30.9
Black/AA 4.3 3.1 2.9
Other 1.2 2.8 3.4
School (%)
Elementary 32.7 50.9 51.7 <0.001***
Middle 30.3 33.8 39.9
High 37.0 15.3 8.4
Economically Disadvantaged (Free/Reduced Lunch Eligible) (%)
Yes 46.7 50.6 47.3 <0.001***
No 53.3 49.4 52.7
Note: *p<0.05, **p<0.01, ***p<0.001
Hays CISD Multi-year Child Obesity Study
Results – Overweight and Obesity in Elementary Schools
Percent Overweight or Obese
2010 – 2011(n=3,477)
2014 – 2015(n=4,046)
2016 – 2017(n=4,129)
p value for difference between
yearsTotal 42.7 40.0 38.6 0.005**
Sex
Male 44.6 42.4 40.6 0.06
Female 40.7 37.4 37.3 0.07
Ethnicity
Hispanic 49.7 45.4 44.8 0.003**
Non-Hispanic White 31.4 31.1 27.6 0.07
Black/AA 47.1 29.9 40.9 0.03*
Other 40.0 33.6 26.7 0.23
Economically Disadvantaged (Free/Reduced Lunch Eligible) (%)
Yes 50.2 44.8 45.9 0.004**
No 36.1 35.3 32.1 0.023*
Note: *p<0.05, **p<0.01, ***p<0.001Hays CISD Multi-year Child Obesity Study
Results – Overweight and Obesity in Middle Schools
Percent Overweight or Obese
2010 – 2011(n=3,219)
2014 – 2015(n=2,681)
2016 – 2017(n=4,129)
p value for difference between
yearsTotal 42.4 37.4 34.3 <.001***
Sex
Male 44.1 38.6 38.2 0.004**
Female 40.6 36.3 30.1 <0.001***
Ethnicity
Hispanic 47.0 41.3 39.5 <0.001***
White 32.9 30.3 25.8 0.006**
Black/AA 41.8 41.3 29.8 0.16
Other 52.9 25.0 26.7 0.06
Economically Disadvantaged (Free/Reduced Lunch Eligible) (%)
Yes 46.8 41.1 41.2 0.006**
No 37.7 33.8 28.8 <0.001***
Note: *p<0.05, **p<0.01, ***p<0.001Hays CISD Multi-year Child Obesity Study
Results – Overweight and Obesity in High Schools
Percent Overweight or Obese
2010 – 2011(n=3,963)
2014 – 2015(n=1,215)
2016 – 2017(n=668)
P value for difference between
yearsTotal 31.8 35.8 37.7 0.04*
Sex
Male 35.7 38.3 34.6 0.60
Female 27.8 33.2 43.9 0.001**
Ethnicity
Hispanic 35.2 36.7 38.4 0.63
White 26.5 28.3 33.3 0.45
Black/AA 29.1 28.1 50.0 0.37
Other 38.5 30.0 50.0 0.65
Economically Disadvantaged (Free/Reduced Lunch Eligible) (%)
Yes 35.7 34.2 38.1 0.72
No 29.1 34.2 37.9 0.04*
Note: *p<0.05, **p<0.01, ***p<0.001Hays CISD Multi-year Child Obesity Study
Results – Distribution of Hispanic Students2010 – 2011 2014 – 2015 2016 - 2017
Hays CISD Multi-year Child Obesity Study
Results – Distribution of Non-Hispanic White Students
2010 – 2011 2014 – 2015 2016 - 2017
Hays CISD Multi-year Child Obesity Study
Results – Distribution of Economically Disadvantaged Students
2010 – 2011 2014 – 2015 2016 - 2017
Hays CISD Multi-year Child Obesity Study
Results – Distribution of Overweight and Obese Students
2010 – 2011 2014 – 2015 2016 - 2017
Hays CISD Multi-year Child Obesity Study
ConclusionElementary School Students• Significant decreases in the proportion of overweight and obesity• Significant decreases in the proportion of overweight and obesity
in Hispanic students• Significant decreases in the proportion of overweight and obesity
in both non-economically disadvantaged and economically disadvantaged students
Middle School Students• Significant decreases in the proportion of overweight and
obesity overall• Significant decreases in the proportion of overweight and
obese both male and female middle school students• Significant decreases in the proportion of overweight and
obesity in both non-economically disadvantaged and economically disadvantaged students
Hays CISD Multi-year Child Obesity Study
ConclusionHigh School Students• Marginally significant increase in the proportion of overweight and
obesity • While the changes in economically disadvantaged students were
significant, the prevalence of overweight and obesity among this group is still higher than that of non- economically disadvantaged students in both elementary and middle school.
• Similarly, there was a significant decrease in the proportion of overweight and obese among Hispanic students, but the proportion was still higher than non-Hispanic white students in both elementary and middle schools students.
Hays CISD Multi-year Child Obesity Study
Conclusion• The maps provided information about trends
over time:– Increasing geographic segregation across the I-35
corridor between socioeconomic status and racial/ethnic groups.
• Despite the decreases seen in proportion of overweight and obese students in some areas of the school district, disparities remain between economically disadvantaged students and their higher income counterparts.
Hays CISD Multi-year Child Obesity Study
Limitations• Due to the nature of cross sectional study design, it is difficult to
derive causal relationships from cross-sectional analysis, though the design is appropriate for surveillance. 8
• There was a significant change in the sample size between age groups; middle and high school sample sizes decreased over time.
• Maps should be interpreted with the understanding that aggregate level data cannot be used to make inferences at the individual level.
• The use of an administrative boundary such as the census tracts introduces a source of bias that can significantly impact results. – The Modifiable Areal Unit Problem (MAUP) affects results when point-
based measures of spatial phenomena are aggregated into districts, for example, population density or illness rates. The resulting summary values are influenced by both the shape and scale of the aggregation unit.
• FITNESSGRAM data has issues related to excessive instructional time taken for testing, inaccurate scoring, and increased sedentary time while students wait to be tested. 9
Hays CISD Multi-year Child Obesity Study
Recommendations• Though this study showed decreases in the proportion of
overweight and obese Hispanic and economically disadvantaged students, future efforts should continue to prioritize these high risk groups for health promotion programs and policies due the persistent disparities between these groups and non-Hispanic white and higher income students.
• While Hays CISD has implemented wellness policies, Coordinated Approach to Child Health programs, and other school health interventions, improving the nutrition and physical activity environments both in schools and in communities has the potential to improve child health, especially among vulnerable populations.
• School based obesity prevention must take into consider the multitude of influences that affect child health, including school environment and the broader social and community contexts.
Hays CISD Multi-year Child Obesity Study
STUDY 2: STUDENTS COMPARED TO THEMSELVES OVER TIME
Hays CISD Multi-year Child Obesity Study
Purpose
• The purpose of this project was to assess the within student changes in overweight and obesity and cardiovascular fitness over time.
• A cohort of Hays CISD students who were measured in school year 2010-2011 and again in 2014-2015 were used for this study.
Hays CISD Multi-year Child Obesity Study
MethodsData Sources• FITNESSGRAM assessments from the 2010-2011 school year
and 2014-2015 school year for student BMI – Aerobic capacity as a measure of fitness is measured in FITNESSGRAM
through the Pacer test, one mile run or one mile walk test. These tests are used to approximate VO2max and categorized as in “Healthy Fitness Zone,” “Needs Improvement,” or “Needs Improvement –Health Risk.
• Texas Education Agency’s PEIMS data were used for the demographic characteristics including sex, age, race/ethnicity, and economic disadvantage as measured by eligibility for free or reduced lunch.
• Student level records were matched for FITNESSGRAM and PEIMS data for each student across the two time points.
Hays CISD Multi-year Child Obesity Study
Methods• Data analysis for this study included calculating baseline
demographic characteristics, and determining changes in weight status and aerobic capacity among students over time. – Pearson Chi Square tests were used to determine statistical
significance for the changes between years. – Changes in the percent of overweight or obese students
were calculated by sex, race/ethnicity, and economic disadvantage status. The level for statistical significance was set to p<.05 for all analyses.
• This study did not use mapping because student campus and home addresses may have changed between 2010 and 2014– Making spatial inferences about the relationship between
place and health would be impacted by the change in address.
Hays CISD Multi-year Child Obesity Study
Results - Baseline Characteristics of Students (2010-2011)
Total(n=1,408)
Mean age in years (SD) 10.55 (1.61)School Type Attended, n (%)
Elementary 1124 (79.8)Middle 284 (20.2)
Race/Ethnicity, n (%)Hispanic 896 (63.6)White, non-Hispanic 413 (29.3)Black 53 (3.8)Other 46 (3.3)
Weight Status, n (%)Underweight 40 (2.8)Healthy 784 (55.7)Overweight 265 (18.8)Obese 319 (22.7)
Economically disadvantaged (Free/Reduced Lunch), n (%)Yes 670 (48.0)No 726 (52.0)
Hays CISD Multi-year Child Obesity Study
Results - Overweight or Obese by year and demographic characteristics
Percent overweight or obese
2010 – 2011(n=1408)
2014 – 2015 (n=1408)
Total 41.5 36.7**Sex
Male 42.4 36.1*Female 40.7 37.1
Race/EthnicityHispanic 46.7 38.8**White, non-Hispanic 30.5 32.0Black 45.3 37.7Other 34.8 34.8
Economically disadvantaged (Free/Reduced Lunch)Yes 47.5 39.4**No 36.1 34.0
Grade at baseline3rd 38.6 38.64th 44.5 36.55th 47.5 35.7**6th 41.6 35.27th 38.1 27.48th 40.0 36.0
Note: for changes between years, *p<.05, **p<.01, ***p<.001Hays CISD Multi-year Child Obesity Study
Results - Aerobic capacity in Healthy Fitness Zone (HFZ)
Percent in HFZ2010 – 2011
(n=1394)2014 – 2015
(n=544)Total 81.9 56.4Sex
Male 86.6 42.3Female 77.7 65.6
Race/EthnicityHispanic 78.7 53.3White, non-Hispanic 89.4 65.0Black 77.4 58.3Other 81.8 30.8
Economically disadvantaged (Free/Reduced Lunch)Yes 78.7 50.6No 85.0 63.1
Grade at baseline3rd 98.2 69.94th 66.7 35.75th 62.3 61.96th 69.4 48.87th 81.7 36.28th 66.7 26.5
Note: due to unequal sample sizes, statistical tests were not run to determine changes between yearsHays CISD Multi-year Child Obesity Study
Students compared to self over time –BMI Total Sample
2.8
2.8
60.6
55.7
17.5
18.8
19.1
22.7
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
2014 - 2015
2010 - 2011
Underweight Healthy Overweight ObeseHays CISD Multi-year Child Obesity Study
Students compared to self over time – BMI by Sex
4
3.3
59.9
54.3
14.9
19
21.2
23.4
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Male
Underweight Healthy Overweight Obese
1.6
2.4
61.2
56.9
19.9
18.7
17.2
22
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Female
Underweight Healthy Overweight Obese
Hays CISD Multi-year Child Obesity Study
Students compared to self over time –BMI by Ethnicity
4.6
5.8
63.4
63.7
17.0
15.7
15.0
14.8
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Non-Hispanic White
Underweight Healthy Overweight Obese
3.8
1.9
58.5
52.8
20.7
17.0
17.0
28.3
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Black/African American
Underweight Healthy Overweight Obese
0
6.5
65.2
58.7
13.0
10.9
21.7
23.9
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Other Race/Ethnicity
Underweight Healthy Overweight Obese
2.0
1.3
59.2
52.0
17.9
20.8
21.0
25.9
0.0 20.0 40.0 60.0 80.0 100.0
2014 - 2015
2010 - 2011
Hispanic
Underweight Healthy Overweight Obese
Hays CISD Multi-year Child Obesity Study
Students compared to self over time–BMI by Economic Disadvantage
2.2
1.9
58.4
50.6
17.6
20.3
21.8
27.2
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Economically Disadvantaged
Underweight Healthy Overweight Obese
3.3
3.4
62.7
60.5
17.6
17.5
16.4
18.6
0% 20% 40% 60% 80% 100%
2014 - 2015
2010 - 2011
Not Economically Disadvantaged
Underweight Healthy Overweight Obese
Hays CISD Multi-year Child Obesity Study
Conclusion• Overall, significant decreases in the proportion of overweight and obesity
– Significant decreases being among those students who were obese and therefore at highest risk.
• Significant decreases in the proportion of overweight and obese among:– Male students, – Hispanic students, – 5th grade students at baseline, and– Economically disadvantaged students.
• While the changes in economically disadvantaged students were significant, the prevalence of overweight and obesity among this group is still higher than that of non- economically disadvantaged students.
• Similarly, there was a significant decrease in the proportion of overweight and obese among Hispanic students, but the proportion was still higher than non-Hispanic white students in both years of measurement. Hays CISD Multi-year Child Obesity Study
Limitations• The study used complete case analysis, there may
be differences between the sample of students who had valid measurements at both time points and those students who did not. – Therefore, caution should be taken when generalizing
these findings to Hays CISD as a whole.
• Additionally, the sample size for the aerobic capacity varies widely between the two years, which limits the validity of the results comparing the two time points.
Hays CISD Multi-year Child Obesity Study
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Hays CISD Multi-year Child Obesity Study
