Maximizing retention with high risk participants in a clinical trial

To describe effective retention strategies in a clinical trial with a high risk, low-income, and vulnerable patient population with serious mental illness.

Follow-up assessments were conducted for a randomized clinical tobacco treatment trial at 3, 6, and 12 months postbaseline. Initial follow-up rates of <40% at 3 months led to implementation of proactive retention strategies including obtaining extensive contact information; building relationships with case managers and social workers; contacting jails and prisons; text messaging, e-mailing, and messaging via social networking sites; identifying appointments via electronic medical record; and field outreach to treatment facilities, residences, and parks.

Large urban public hospital.

Participants were current smokers recruited from 100% smoke-free locked psychiatry units.

Assessments covered demographics, substance use, and mental health functioning.

Retention rates were plotted over time in relation to key retention strategies. Chi-square and t-tests were used to examine participant predictors of retention at each follow-up. At the 12-month follow-up, the retention strategies that most frequently led to assessment completion were identified.

The sample (N = 100) was 65% male; age x = 39.5 years (SD = 11.3); 44% non-Hispanic white; 46% on Medicaid and 34% uninsured; 79% unemployed; and 48% unstably housed. Proactive retention strategies dramatically increased follow-up rates, concluding at 3 months = 82.65%, 6 months = 89.69%, and 12 months = 92.78%. Married and divorced/separated/widowed participants, those with higher income, and participants with alcohol or illicit drug problems had increased retention from 3- to 12-month follow-up.

Follow-up rates improved as proactive methods to contact participants were implemented. Dedicated research staff, multiple methods, community networking, and outreach within drug treatment settings improved retention.