Review of retention strategies in longitudinal studies and application to follow-up of ICU survivors

Intensive Care Med (2007) 33:20512057DOI 10.1007/s00134-007-0817-6 REVIEW

Catherine M. Tansey Andrea L. Matt Dale Needham Margaret S. Herridge

Review of retention strategies in longitudinal studies and application to follow-up of ICU survivors

Received: 20 October 2006 Accepted: 11 July 2007 Published online: 15 August 2007 Springer-Verlag 2007

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C. M. Tansey ( ) A. L. Matt M. S. Herridge University Health Network, Department of Medicine, Toronto General Hospital, 585 University Ave, ON M5G 2N2 Toronto, Canadae-mail: [email protected].: [phone] ext 6945Fax: [phone]

C. M. Tansey M. S. Herridge University of Toronto, Institute of Medical Science,Toronto, Canada

D. Needham Johns Hopkins University, Pulmonary and Critical Care Medicine, 1830 East Monument Street, Baltimore 21205, USA

M. S. Herridge University of Toronto, Interdepartmental Division of Critical Care Medicine, Toronto, Canada

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. Design and setting: Literature review and two cohort studies in a tertiary care hospital in Toronto, Canada. Patients and participants: ARDS and SARS patients. Measurements and 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 identied 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, exible 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 eld and patients are satised that they have an important...