Patient recruitment

Patient retention: keeping enrolled patients in the study

By TrialNotice · Updated
Smiling older woman laughing with a coordinator in coral scrubs during a follow up visit
Short answerKeep enrolled patients by reducing visit burden, staying in contact between visits, and keeping the referring physician informed. The average dropout rate in Phase II and III trials is 19.1%, according to Tufts CSDD. Evidence on specific tactics is thinner than many vendors suggest: a 2021 Cochrane review of 81 retention trials found most tested ways to improve questionnaire response, few tested getting participants back to sites, and none of the comparisons had high certainty evidence.

How big is the dropout problem?

Tufts CSDD found the average dropout rate in Phase II and III trials rose to 19.1%, up from 15.3% (Tufts CSDD). Every lost patient means missing data for the sponsor and lost revenue for the site.

What does the evidence say about retention tactics?

Less than most people assume. A 2021 Cochrane review identified 81 retention trials from 70 papers. Most interventions aimed to improve postal questionnaire response, there were few evaluations of ways to get participants back to trial sites for follow up, and none of the comparisons were supported by high certainty evidence (Cochrane). Treat confident vendor claims about retention tactics with care.

What practical steps reduce dropout?

  1. Set expectations at consent. Patients who understand the visit schedule and procedures up front are less likely to be surprised later.
  2. Reduce burden. Flexible scheduling, shorter waits, and travel support where the IRB approves it.
  3. Plan for study partners. Many Alzheimer's studies require a study partner (Alzheimer's Association and NIA); their schedule matters as much as the patient's.
  4. Stay in touch between visits with reminders and a named coordinator the patient knows.
  5. Watch early warning signs: rescheduled visits, slower replies, missed calls.

How does the referring physician help retention?

Patients value their doctor's involvement: 95% of CISCRP respondents said it is important for their regular doctor to be aware of studies (CISCRP). A referring physician who is kept informed can reassure a patient who is wavering. Yet nearly 30% of physicians never hear back after referring (Tufts CSDD). Updating them is a retention tactic, not just courtesy.

Does retention start at recruitment?

Yes. Patients referred by a physician who explained the study accurately arrive with realistic expectations. See what physicians need to know before referring.

Get your study in front of the right local physicians

TrialNotice builds a physician referral pipeline around one active study. We identify relevant local physicians within driving distance of your site, send study aligned direct mail, follow up by email and LinkedIn, track engagement with recipient level QR codes, and route warm responses into your site team's workflow.

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Sources

  1. Applied Clinical Trials, "Can Recruitment and Retention Get Any Worse?" (Tufts CSDD screen failure study)
  2. Gillies K. et al., "Strategies to improve retention in randomised trials," Cochrane Database of Systematic Reviews (2021)
  3. Alzheimer's Association and National Institute on Aging national recruitment strategy announcement (2018)
  4. CISCRP, Highlights from the 2017 Perceptions and Insights Study
  5. Applied Clinical Trials, "Tufts CSDD Study Explores Low Recruitment Rates"

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