Minimising and Handling Non Response in Survey Samples in Ireland

1. Minimising and Handling Non Response in Survey Samples in Ireland Heavey PM, Viljoen K, O’Brien J, Murrin C and Kelleher C

2. National Nutrition Surveillance Centre • To provide accurate, reliable and timely information in an accessible form at short notice • To monitor trends in health status correlated with all aspects of the food chain and advise on these findings for health planners • To provide a source of information and research expertise, particularly in nutritional epidemiology and surveillance methodology to those wishing to mount specific projects such as micro-surveys

3. WHO Childhood Obesity Surveillance Initiative • Lifeways Cross Generation Cohort Study

4. WHO Childhood Obesity Surveillance • The growing problem of obesity in children is not unique to Ireland and the World Health Organisation (WHO) has recently issued recommendations and guidelines for regular collection of data on weight, height and waist and hip circumference in children worldwide • The Department of Health and Children and the Health Service Executive commissioned the National Nutrition Surveillance Centre, to carry out this work in the Republic of Ireland

5. Aims • The core objective is to measure in primary school children: • Weight, height and waist circumference • Prevalence of normal weight, overweight, obesity and mean BMI • To measure trends in overweight and obesity in children: • To have a correct understanding of the progress of the epidemic • To compare within the WHO European Region

6. Two rounds of data collection (2008 and 2010) In 2008, only 7 year old children were measured • In 2010, this was extended to include measuring both 7 and 9 year old children • In addition, further data collection on the children’s diet and lifestyle was collected (Family Survey) • School principals were also interviewed to gather information about the school environment and any school policies regarding physical activity and healthy eating

7. Need to consider • Response rate at each level: • School • Parent • Child

8. First round of data collection (2008) • Childhood obesity- sensitive issue • In communication with schools, parents and children- referred to growth surveillance • Provided free phone numbers and email for queries and questions from both schools and parents • Training of Nutritionists/Dieticians (Females) • Measurements -2 trained Dieticians present

9. In total 16 Nutritionists were recruited to carry out the fieldwork in the schools • They were recruited from around the country so that they could visit schools that were in their locality • All Nutritionists worked in teams of two • Nutritionists were invited to attend one of three training days • They attended a one-day training session in anthropometric measurements and data collectionfollowing a standardised protocol drawn up by the WHO

10. Schools were geomapped and teams were located around the country • Measurements took place at time convenient for the school • All letters/ forms approved by NALA (National Adult Literacy Agency) • All forms translated into Irish and Polish • All measurements were done in a private room or behind screens to ensure confidentiality and privacy (2 people present) • Parents were made aware that they could be present • Provided parents with results on request

11. 163 schools took part in the first round of the WHO Surveillance Initiative • These same schools were invited to participate in the second round • All schools were sent an initial letter, information pack and school consent form • Reminder letter followed by a phone call • In total 131 schools consented to taking part which was a response rate of 80% • The majority of schools that did not consent gave the reason that there was too much going on in the school at that time and many of the schools were undergoing renovation/extensions so it was not suitable at this time

12. Response • A total of six thousand, three hundred and sixty three children were on the school register for both 1st and 3rd class • 4038 children were measured (63.46%) • 2075 parents did not consent (32.6%) • 24 children refused to be measured on the day (0.37%) • 226 children were absent (3.55%)

13. The Lifeways Cross-Generational Study • Lifeways is a unique cohort study, designed to capture Irish longitudinal life-course data, by recruiting three generations of the same family • 1082 mothers were recruited from two maternity hospitals in Ireland (Dublin and Galway) • Children were measured at birth • Follow up at 5 years-children were measured in their own homes • Follow up at 9 years –ongoing

14. 5 year follow up • Measurement of children took place in own home • Carried out by trained Dieticians • Response rate of 49%

15. 9 year follow up • To maintain response rate- Family doctor will carry out the measurements • Parents more likely to respond to ‘free’ medical check up by doctor • Created Facebook page, website Twitter, Newsletters, greeting cards • All letters/communication checked by NALA • To date >400 of the 500 families have consented to participate in this round • Geomapping of Family Practices to co-ordinate efficient data collection

16. Thank You Any questions?