Methodological Approaches to Studying Gender
and Health Among Children using NationallyR
Representative
t ti Data
D t
Meena Fernandes
AcademyHealth - Gender and Health Interest Group
June 26, 2010
Dissertation Papers
 School
Nutrition Policies
1) The Effect of Soft Drink Availability in Elementary Schools on
Consumption (Journal of the American Dietetic Association, 2008)
2) The Impact of State Policies on the School Food Environment,
Dietary Intake and Obesity

School Physical Activity Policies
3)) Facility
y Provision in Elementary
y Schools: Correlates with Physical
y
Education, Recess and Obesity (Preventive Medicine, 2010)
4) The Role of School Physical Activity Programs in Child Body Mass
Trajectory
ajecto y (Jou
(Journal
a of
o Physical
ys ca Activity
ct ty a
and
d Health,
ea t , in press)
p ess)
 Childhood
Obesity Costs Model
5)) Estimating
g the Lifecycle
y
Health Care Cost Burden of Child Obesity
y
(presented at iHEA, 2009 and NIH Dynamic Modeling Workshop, 2009)
Meenakshi Fernandes – UIC Brownbag - March-17 - 2
Diet and Physical Activity Among Children


Health behaviors develop in childhood
Spheres of influence include peers, parents, neighborhoods,
schools, government
– Constrained choice model (Bird
(Bi d and
d Rieker,
Ri k 2008)
– Limited autonomy


Behaviors
Beha
iors ma
may track into adulthood
ad lthood and underlie
nderlie chronic
disease development
Gender differentials in chronic disease burden and longevity
Meenakshi Fernandes – UIC Brownbag - March-17 - 3
Child Health and School Policies


Behavioral differences by gender may emerge or widen in
youth
School policies can potentially mitigate disparities
– Feasibility
– Relevant programs (e.g. school-community partnerships)
– Potentiallyy cost-effective

Behaviors learned at school may “spillover” to home
environment
Meenakshi Fernandes – UIC Brownbag - March-17 - 4
Research Questions

How do health behaviors vary by gender?
– Diet
– Physical activity

Do conditional responses to policies vary by gender?
– Responses: food consumption and obesity risk
– Policies: food availabilityy and p
physical
y
activity
yp
programs
g
Estimate population-level effects and impacts of existing
p
policies
Meenakshi Fernandes – UIC Brownbag - March-17 - 5
Prior Studies

Nutrition
– ~ 1 iin 5 children
hild
consume att lleastt 5 ffruits
it or vegetables
t bl a
day (Krebs Smith, 1998)
– Teenage boys consume more fruits/vegetables (4.3 vs 3.5
servings and soft drinks (38 vs 27 oz) than girls

Physical Activity
– 42% of children ages 6-11 meet recommended PA levels
(Troiano, 2008)
– Levels lower among girls and racial/ethnic minorities
– Trajectory analyses focus on teenage years
– Previous study found impact of PE for overweight girls
b
between
K and
d grade
d 1 (D
(Datar and
dS
Sturm, 2004)
Meenakshi Fernandes – UIC Brownbag - March-17 - 6
Data: Early Childhood Longitudinal Survey

Conducted by Dept of Education

Follows national sample from kindergarten to 8th grade
–
–
–
–

Asian/pacific islanders over-sampled
Private schools are included
Child, school administrator and parent components
State FIPS codes for schools
Food Consumption Questionnaire in 5th grade (spring 2004)
and 8th grade (spring 2007) waves

Physical activity measures in several waves

Child height/weight measured in every wave
Meenakshi Fernandes – UIC Brownbag - March-17 - 7
Child Body Mass: BMI Percentile

Function of BMI, gender and age

BMI = weight(kg)/[height(m)
i ht(k )/[h i ht( )2]


Constructed from CDC’s Clinical
Growth Charts
– Percentiles based on reference
population
– Surveys conducted 1963
1963-1994
1994
Ranges from 0 to 100
– Obese if exceeds 95
– Overweight/obese if exceeds 85
Meenakshi Fernandes – UIC Brownbag - March-17 - 8
Descriptive Statistics (5th Grade Sample)
n
Age
Below poverty threshold
Race/ethnicity
White
Black
Hispanic
O
Other
Hours of television per wk
Days physically active per
wk*
BMI percentile
Children
5 948
5,948
11
25%
61%
14%
17%
8%
%
16
3.8
66.9
* 20 min or more of vigorous physical activity
a day as reported by parent
Schools
1 563
1,563
N
Region
Northeast
Midwest
South
West
Degree of urbanization
Urban
Suburban
Rural
Enrollment
0-299
300-499
500 or more
Private, %
18%
28%
35%
19%
33%
%
43%
24%
20%
38%
43%
12%
Meenakshi Fernandes – UIC Brownbag - March-17 - 9
Boys Consume More Soft Drinks at School but
Differences are Small (5th grade in 2004)
Meenakshi Fernandes – UIC Brownbag - March-17 - 10
Policies Disproportionately Affected Black Children

Policies to limit availability were introduced between 2004
and 2007

37.9% of blacks affected as compared with 32.2% of
Whites and 20
20.1%
1% of Hispanics
Limit and standard (n=622)
Standard only (n=1131)
Limit only (n=526)
Meenakshi Fernandes – UIC Brownbag - March-17 - 11
Physical Activity Declines Among Girls but not Boys
Girls (n=4248)
Boys (n=4364)
4.4
4.2
4
3.8
3.6
34
3.4
3.2
3
K
Grade 3
Grade 5
Meenakshi Fernandes – UIC Brownbag - March-17 - 12
However Sports Team Participation Increases and TV
Hours Watched is Stable
K
Sports Team
S
T
Participation
P i i i
Girls
Boys
Diff
Public Park Use
Girls
Boys
Diff
Hours of TV per Week
Girls
B
Boys
DIff
Grade 1
Grade 3
Grade 5
28.5
45.6
17 1
17.1
41.4
55.5
14 1
14.1
48.7
58,7
10 1
10.1
59.2
64.8
5.6
53.5
58.4
4.9
53.2
57.5
4.3
9.1
96
9.6
0.5
8.0
83
8.3
0.3
10.6
11 0
11.0
0.4
Grade 8
9.7
10 4
10.4
0.7
Meenakshi Fernandes – UIC Brownbag - March-17 - 13
Assessed Impact of PE and Recess on Body Mass
(1st thru 5th grades)

Growth curve modeling approach
– Child
Children nested
t d iin schools
h l over titime
– Child age was entered in as a random slope

K explanatory
Key
l
t
variables
i bl were PE and
d recess titime
– Hours per week
– National recommendations

Models controlled for child and school factors (time varying
and time invariant))
Meenakshi Fernandes – UIC Brownbag - March-17 - 14
Obesity Prevalence Increases Over Time and is Greater
Among Boys
Girls
Boys
25
Obesity
y, %
20
15
10
5
0
Grade 1
Grade 3
Grade 5
Meenakshi Fernandes – UIC Brownbag - March-17 - 15
PE Time Increases While Recess Decreases Over Time
st
Physical education (PE) time
Minutes per week
Recommended level, %
D
Days
per week
k
Provided daily, %
Recess time
Minutes per week
Recommended level, %
Days per week
Provided daily, %
rd
th
1 Grade
(n= 10
10,625)
625)
3 Grade
(n= 8
8,544)
544)
5 Grade
(n= 7
7,306)
306)
65.7
7.0
22
2.2
12.0
69.4
8.9
22
2.2
9.8
78.2
11.7
22
2.2
10.8
111.2
70.7
4.6
87.5
106.0
68.3
4.5
69.2
87.9
53.9
4.3
71.3
Meenakshi Fernandes – UIC Brownbag - March-17 - 16
An Additional Hour of PE or Recess Is Not
Statistically Significant
Boys
Coeff
(SE)
n
4,137
-0.51
-0.35
0.31
0.21
875
-0.07
-0.03
0 03
2,407
3,413
n
Hours per week
Overall
PE
Recess
>90th percentile
PE
Recess
>60th percentile
PE
ecess
Recess
>30th percentile
PE
Recess
Girls
Coeff
(SE)
4,109
0.04
-0.23
0.31
0.21
0.15
0 10
0.10
804
-0.08
-0.16
0 16
0.15
0 11
0.11
-0.39
0.13
0
3
0.27
0.19
0
9
2,232
-0.22
-0.23
0 3
0.27
0.19
0
9
---
---
3,323
0.14
-0.34
0.3
0.2
Meenakshi Fernandes – UIC Brownbag - March-17 - 17
Meeting Recommended Levels of PE is Protective
for Boys but not Girls
Boys
Coeff
(SE)
4,137
-1.56
-0.81
0 81
0.75
0 44
0.44
875
-0.30
-0.34
2,407
3 413
3,413
n
Recommended time c
Overall
PE
Recess
>90th percentile
PE
Recess
>60th percentile
PE
Recess
>30th percentile
PE
Recess
Girls
Coeff
(SE)
4,109
0.05
-0.69
0 69
0.74
0 41
0.41
0.41
0.21
804
-0.22
-0.39
0.43
0.21
-1.07
-0.18
0.69
0.38
2,232
-0.50
-0.60
0.69
0.38
-1.45
-1
45
-0.83
0.72
0
72
0.41
3 323
3,323
-0.12
-0
12
-0.85
0.74
0
74
0.41
n
*
*
*
*
Meenakshi Fernandes – UIC Brownbag - March-17 - 18
Conclusions

Few striking differences by gender for school-based food
consumption

Gender differences in physical activity are more evident,
but not consistent
– Participation in organized sports increases
– TV hours remains constant
– Physical activity declines

School PE p
policies mitigate
g
body
y mass difference between
boys and girls in elementary school
Meenakshi Fernandes – UIC Brownbag - March-17 - 19
Obesity Prevalence by Age and Gender *
girls
boys
45%
40%
35%
30%
25%
20%
15%
10%
<10
10-20
20-30
30-40
40-50
50-60
60-70
70-80
Age
* NHANES 2007-2008
Meenakshi Fernandes – UIC Brownbag - March-17 - 21