title: Review of retention strategies in longitudinal studies and application to follow-up of ICU survivors.
abstract: OBJECTIVE
  To review the literature on retention strategies in follow-up studies and their relevance to critical care and to comment on the Toronto experience with the acute respiratory distress syndrome (ARDS) and severe acute respiratory syndrome (SARS) follow-up studies.
  
  
  METHODS
  Literature review and two cohort studies in a tertiary care hospital in Toronto, Canada.
  
  
  METHODS
  ARDS and SARS patients.
  
  
  RESULTS
  Review articles from the social sciences and medicine are summarized and our own experience with two longitudinal studies is drawn upon to elucidate strategies that can be successfully used to attenuate participant drop-out from longitudinal studies. Three key areas for retention of subjects are identified from the literature: (a) respect for patients: respect for their ideas and their time commitment to the research project; (b) tracking: collect information on many patient contacts at the initiation of the study and outline tracking procedures for subjects lost to follow-up; and (c) study personnel: interpersonal skills must be reinforced, flexible working hours mandated, and support offered. Our 5-year ARDS and 1-year SARS study retention rates were 86% and 91%, respectively, using these methods.
  
  
  CONCLUSIONS
  Strategies to reduce patient attrition are time consuming but necessary to preserve internal and external validity. When the follow-up system is working effectively, researchers can acquire the necessary data to advance knowledge in their field and patients are satisfied that they have an important role to play in the research project.
authors: Department of Medicine, Toronto General Hospital, University Health Network, 585 University Ave, ON M5G 2N2, Toronto, Canada. catherine.tansey@utoronto.ca
authors: Catherine M
authors: CM
authors: Tansey
authors: Andrea L
authors: AL
authors: Matté
authors: Dale
authors: D
authors: Needham
authors: Margaret S
authors: MS
authors: Herridge
mesh_terms: D006801:Humans; D007362:Intensive Care Units; D008137:Longitudinal Studies; D009864:Ontario; D010352:Patient Dropouts; D010358:Patient Participation; D017741:Survivors
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