Presentation at the Faculty of Public Health annual conference 2016

1. Insert name of presentation on Master
Slide
A Secondary Analysis of the Cross-Sectional
Data Available in the ‘Welsh Health Survey for
Children’ to Identify Risk Factors Associated
with Childhood Obesity in Wales.
Presented by :Claire Beynon
Supervisor :Professor David Fone, Cardiff University

2. Claire Beynon
Why is childhood obesity a
problem?
• Prevalence of childhood obesity in Wales 12%.
• Impacts on both quality and quantity of life.
• Immediate effects:
low self esteem; bullying; depression; type II
diabetes.
• Long term effects:
Premature mortality; adult morbidity.
• Obesity costs £73 million per annum in Wales.

3. Claire Beynon
Why is childhood obesity a
problem?
Lobstein and
Jackson
Leach in
Foresight
Report, UK
Government
Office for
Science,
2007.

4. Claire Beynon
Research Question
• What are the important risk factors for childhood
obesity for children aged 4 to 15 years in Wales?
Research Objectives
• Identify and quantify cross-sectional associations
between obesity in children in Wales aged 4-15 years
and the risk factors available in the Welsh Health
Survey.
• Make recommendations for policy where appropriate.

5. Claire Beynon
Study Design
• Secondary Analysis of Data from the WHS.
• Dataset included n=11,279 children (aged 4-15 years)
between 2008 and 2011.
• Descriptive statistics, and logistic regression.

6. Claire Beynon
Risk Factors
• Socio-demographic/socioeconomic variables:
Sex, age, National Statistics Social Classification
(NSSEC), housing tenure and Welsh Index of Multiple
Deprivation (WIMD).
• Lifestyle variables:
Unhealthy food consumption; sugar sweetened
beverages; physical activity (PA) levels
• Illness:
Currently treated illnesses.

7. Claire Beynon
Results
Risk Factor Odds Ratio 95% CI P value
Sex Male Reference
Female 0.79 0.70 to 0.89 p<0.001*
Age 4-6 Reference
7-9 1.42 1.19 to 1.70 p<0.001*
10-12 1.65 1.39 to 1.97 p<0.001*
13-15 1.44 1.20 to 1.73 p<0.001*
Significant association between childhood obesity and the
following factors denoted with *

8. Claire Beynon
Results
Risk Factor OR 95% CI P value
NSSEC 3 Professional/ Managerial Reference
Intermediate 1.17 0.98 to 1.38 0.08
Routine/ Manual 1.32 1.14 to 1.54 p<0.001*
WIMD Lowest Reference
Low 1.08 1.19 to 1.70 p=0.44
Mid 1.23 1.01 to 1.50 p=0.04*
High 1.33 1.09 to 1.62 p=0.005*
Highest 1.23 0.99 to 1.53 p=0.06

9. Claire Beynon
Results
Risk Factor OR 95% CI P value
Illness No illness Reference
One illness 1.20 1.05 to 1.38 0.008*
Two or more illnesses 1.50 1.22 to 1.85 p<0.001*
Physical
Activity
Meets recommendation Reference
Does not meet
recommendation
1.33 1.17 to 1.52 p<0.001*

10. Claire Beynon
Results
Risk Factor OR 95% CI P value
Fruit & Veg Not daily Reference
Both daily 0.96 0. 85 to 1.09 p=0.82
SSB Not daily Reference
Daily 1.02 0.83 to 1.27 p=0.82
Junk food Not daily Reference
Daily 0.89 0.79 to 1.01 p=0.08
No significant association between childhood obesity and
the following factors:

11. Claire Beynon
Strengths of the study
• WHS uses stratified random sampling.
• Results for 3000 children achieved per annum.
• Good response rate at 75%.
• Known confounding accounted for by use of multivariable
analysis.
• Provides new insights into existing data.
• Information from Wales on which to base Welsh policy.

12. Claire Beynon
Limitations of the study
• Risk of bias, e.g. recall bias; reporting of food
consumption and physical activity reporting. Non
response bias.
• Reverse causality possible due to study design.
• Selection bias, private homes surveyed (not
institutions).
• Unknown confounding possible (not all risk factors
measured).
• Interactions not explored.

13. Claire Beynon
Conclusions
• Some risk factors associated with childhood obesity
are not modifiable (e.g. sex and age of the child).
• Some risk factors are not easily modifiable in the short
term, e.g. the circumstances of the family (NS-SEC
classification of the parent and housing tenure).
• Two findings are potentially more easily modifiable:
– the association between childhood obesity
and not meeting the PA recommendations
– the NHS response to the care planning of
children with a long term condition.

14. Claire Beynon
Recommendations
• Increase physical activity in schools to an hour a day,
so all children have levels of PA that protect them
from obesity without increasing inequalities in health.
• Extend the number and type of physical activity
options available to children across Wales both in
schools and out of school.
• Utilise the CMP feedback to provide advice on relevant
physical activity options that are affordable and
accessible e.g. green spaces; walks; free swimming.
• Ensure all children with a long term condition get help
to avoid or manage obesity through an holistic care
package.

15. Claire Beynon
Current Recommendations
• Physical activity

16. Claire Beynon
Results
Significant association between childhood obesity
and the following factors:
• being female OR 0.79 (95% CI: 0.70 to 0.89,
p<0.001);
• older age categories than the reference group (4-6
years) with ORs varying between 1.42 and 1.65 (all
significant at p<0.001);
• parents being in the routine, manual, never worked or
long term unemployed group OR 1.32 (95% CI: 1.14
to 1.54, p<0.001);

17. Claire Beynon
Results
Significant association between childhood obesity
and the following factors:
• mid and high quintiles of the WIMD.
OR for mid 1.23 (95% CI: 1.01 to 1.50, p=0.04) and
for high deprivation OR 1.33 (95% CI: 1.09 to 1.63,
p=0.005);
• having one or two currently treated illnesses.
OR for one illness 1.20 (95%CI: 1.05 to 1.38,
p=0.008) and for two or more illnesses OR 1.50 (95%
CI: 1.22 to 1.85, p<0.001)
• not meeting the PA recommendations OR 1.33 (95%
CI: 1.17 to 1.52, p<0.001).