T Björk1, D Clinton, C Norring. 1. Psychiatric Research Centre, Orebro County Council, S-701 16 Orebro, Sweden. tabita.bjork@orebroll.se
Abstract
OBJECTIVE: Lack of participation in follow-ups is thought to be a serious bias in outcome research on eating disorders; however, little systematic knowledge exists about the problem. The present study aimed to delineate non-participation in long-term follow-up research, and explore the reasons for non-participation. METHOD: Eating disorder patients (N=840) entering a naturalistic, longitudinal multi-centre study were divided into participators (N=508) and non-participators (N=332) in 36-month follow-ups. Non-participators were further classified as either active (i.e. refused participation or failed to attend scheduled appointments) or passive non-participators (i.e. could not be traced). RESULTS: Active non-participators exhibited significantly lower levels of general and eating disorder psychopathology at intake compared to participators, while passive non-participators reported higher levels of hostility. DISCUSSION: Systematic exploration of non-participation in longitudinal research can help to mitigate the problem of indistinct results due to missing data. Barriers to successful longitudinal research and how to overcome non-participation at endpoint are discussed.
OBJECTIVE: Lack of participation in follow-ups is thought to be a serious bias in outcome research on eating disorders; however, little systematic knowledge exists about the problem. The present study aimed to delineate non-participation in long-term follow-up research, and explore the reasons for non-participation. METHOD:Eating disorderpatients (N=840) entering a naturalistic, longitudinal multi-centre study were divided into participators (N=508) and non-participators (N=332) in 36-month follow-ups. Non-participators were further classified as either active (i.e. refused participation or failed to attend scheduled appointments) or passive non-participators (i.e. could not be traced). RESULTS: Active non-participators exhibited significantly lower levels of general and eating disorder psychopathology at intake compared to participators, while passive non-participators reported higher levels of hostility. DISCUSSION: Systematic exploration of non-participation in longitudinal research can help to mitigate the problem of indistinct results due to missing data. Barriers to successful longitudinal research and how to overcome non-participation at endpoint are discussed.