Who does not participate in a follow-up postal study? a survey of infertile couples treated by in vitro fertilization
- Penelope TroudeAffiliated withINEDINSERM, Center for Research in Epidemiology and Population Health, CESP U1018Univ Paris Diderot, Sorbonne Paris Cité, Service de Santé Publique et Economie de la Santé Email author
- , Estelle BaillyAffiliated withINED
- , Juliette GuibertAffiliated withLaboratoire de Procréation Médicalement Assistée, Institut Mutualiste de Montsouris
- , Jean BouyerAffiliated withINEDINSERM, Center for Research in Epidemiology and Population Health, CESP U1018Univ Paris-Sud, UMRS 1018
- , Elise de La RochebrochardAffiliated withINEDINSERM, Center for Research in Epidemiology and Population Health, CESP U1018Univ Paris-Sud, UMRS 1018
- , for the DAIFI Group
A good response rate has been considered as a proof of a study’s quality. Decreasing participation and its potential impact on the internal validity of the study are of growing interest. Our objective was to assess factors associated with contact and response to a postal survey in a epidemiological study of the long-term outcome of IVF couples.
The DAIFI study is a retrospective cohort including 6,507 couples who began an IVF program in 2000-2002 in one of the eight participating French IVF centers. Medical data on all 6,507 couples were obtained from IVF center databases, and information on long-term outcome was available only for participants in the postal survey (n = 2,321). Logistic regressions were used to assess firstly factors associated with contact and secondly factors associated with response to the postal questionnaire among contacted couples.
Sixty-two percent of the 6,507 couples were contacted and 58% of these responded to the postal questionnaire. Contacted couples were more likely to have had a child during IVF treatment than non-contactable couples, and the same was true of respondents compared with non-respondents. Demographic and medical characteristics were both associated with probability of contact and probability of response. After adjustment, having a live birth during IVF treatment remained associated with both probabilities, and more strongly with probability of response. Having a child during IVF treatment was a major factor impacting on participation rate.
Non-response as well as non-contact were linked to the outcome of interest, i.e. long-term parenthood success of infertile couples. Our study illustrates that an a priori hypothesis may be too simplistic and may underestimate potential bias. In the context of growing use of analytical methods that take attrition into account (such as multiple imputation), we need to better understand the mechanisms that underlie attrition in order to choose the most appropriate method.
KeywordsInfertility IVF Postal survey Response rate
- Who does not participate in a follow-up postal study? a survey of infertile couples treated by in vitro fertilization
- Open Access
- Available under Open Access This content is freely available online to anyone, anywhere at any time.
BMC Medical Research Methodology
- Online Date
- July 2012
- Online ISSN
- BioMed Central
- Additional Links
- Postal survey
- Response rate
- Author Affiliations
- 1. INED, 133 boulevard Davout, 75940, Paris Cedex 20, France
- 2. INSERM, Center for Research in Epidemiology and Population Health, CESP U1018, 94276, Le Kremlin-Bicêtre, France
- 3. Univ Paris Diderot, Sorbonne Paris Cité, Service de Santé Publique et Economie de la Santé, 75475, Paris, France
- 4. Laboratoire de Procréation Médicalement Assistée, Institut Mutualiste de Montsouris, 75014, Paris, France
- 5. Univ Paris-Sud, UMRS 1018, 94276, Le Kremlin-Bicêtre, France