Maintaining Subject Retention and Avoiding Study Fatigue
Subject retention is as important as subject recruitment. Losing subjects is actually worse for study results than not having randomized the subject at all. There are multiple methods to impute missing data, but none are as good as having retained the subject in follow-up. The site can use many methods to maintain subject retention, including providing a stipend for visits, providing transportation or travel assistance, and having great staff. Having regular visits, albeit not too frequent, has been shown to be helpful. Letters can be sent to the primary care physicians, to the subjects regarding study milestones, and to the subjects once the randomization unblinding occurs. There are multiple steps that can be used if a subject wishes to withdraw consent that allow the critical information, like vital status, to be maintained.
KeywordsImpute missing data Introduce bias Longevity of studies Medication adherence Stipend Great staff Referring physicians Budget for retention Withdrawal of consent
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