Abstract
Background. Estimation of non-response bias by modelling prevalence as a function of the number of mailings required to achieve a response, or of the cumulative response, has been advocated, but the models have not incorporated age and sex, differential response rates by age and sex, or season of response.Methods. The effect on age-sex standardized prevalence of estimating non-response bias using a variety of models was investigated using data on nine symptom and medication questions from 13 007 subjects in the three English centres of the European Community Respiratory Health Survey. Comparison was made of goodness of fit and the prediction of responses in a 25% follow-up sample with the observed values.Results. Despite low response rates in Cambridge and significant decreases in prevalence with additional mailings or increasing cumulative response in Norwich, there were only small effects on estimated age-sex standardized prevalences. No model was consistently better for any centre or question.Conclusions. The models are useful for exploring the sensitivity of estimated prevalence to non-response bias, but should be used with caution to adjust estimates. Ideally first mailings should be staggered over the whole year so that mailing and season are not confounded, and sufficient mailings or other contacts carried out for the whole sample to ensure a high response rate.
| Original language | English |
|---|---|
| Pages (from-to) | 603-611 |
| Number of pages | 9 |
| Journal | International Journal of Epidemiology |
| Volume | 24 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Jun 1995 |
| Externally published | Yes |
Bibliographical note
Funding Information:without the support of Cambridge FHSA, Suffolk FHSA and Norfolk FHSA. Cheryl Moseley, Sarah Jamieson, Maria Podlejska and Wendy Benwell in Cambridge, Heather Jubb and Helen Leeson in Ipswich and Robert Shepheard and Elise Harpendorp in Norwich provided invaluable help during the postal surveys and during the non-responder follow-up. We also acknowledge the help and support of Dr John Stark (Addenbrookes Hospital, Cambridge), Dr Russell Hall (Ipswich Hospital) and Dr Brian Harrison (West Norwich Hospital). Mr Lai is funded by the Department of Health.
Funding Information:
ACKNOWLEDGEMENTS This study is part of the European Community Respiratory Health Survey and was funded by the National Asthma Campaign. It would not have been possible