Successful techniques for retention of study participants in an inner-citypopulation

The purpose of this work was to describe methods of retaining participants in studies of inner-city populations, including the timing and intensity of contacts; and to describe the characteristics of participants who did not complete all follow-up interviews and/or return all peak flow diaries in th e National Cooperative Inner-City Asthma Study. A cohort study design was u sed involving hospital emergency rooms and community clinics in seven major urban areas. Participants included 1337 4- to 9-year-old asthmatic childre n and their caretakers. Nearly 89% of participants completed 3-, 6-, and 9- month follow-up interviews. The 15% of participants who completed a baselin e interview on the weekends were significantly more likely to complete foll ow-up interviews on a weekend. The percent of follow-up interviews conducte d in person increased over time from 5% to 8%. The percent of participants with complete follow-up increased as the number of contact names increased (86% with zero contacts, 91% with two contracts; p = 0.03, test for trend). Participants who required at least four phone calls to complete the 3- and 6-month assessment were significantly mole likely to be black, have higher participant stress, and have a smoker in the household (p < 0.05). Multipl e logistic regression suggests that higher social support and lower parenta l stress were both predictors of completed interviews. Within our study sam ple of inner-city minority participants with asthmatic children, only a sma ll proportion of participants missed any follow-up interviews. Increased ca retaker stress, decreased social support, and inability to provide several alternate contacts were all predictive of retention problems, Having a flex ible staff, computer tracking, and face-to-face recruitment appear essentia l to achieving nearly complete follow-up within a population historically d ifficult to follow. Controlled Clin Trials 1998;19:544-554 (C) Elsevier Sci ence Inc. 1998.