Having a Primary Care Provider is the Strongest Predictor of Successful Follow-up of Participants in a Clinical Trial.

Purpose: Ethnic minorities, women, and those of low socioeconomic status are widely underrepresented in clinical trials. Few studies have explored factors associated with successful follow-up in these historically difficult-to-reach patients. This study's objective was to identify patient characteristics and methods of contact that predict successful contact for follow-up in an urban, predominantly ethnic minority, majority-women, poor population to help devise strategies to improve retention.

Methods: We retrospectively reviewed records from a prospective randomized control trial of 400 hospitalized chest pain patients to determine which characteristics were associated with successful telephone follow-up at 1 year after enrollment. We assessed demographic variables, medical history, and social factors by using bivariate analyses. A multivariate analysis was performed using variables from the bivariate analysis with ≤ .2.

Results: The overall successful 1-year follow-up rate was 95% (381/400). Study participants who completed follow-up were significantly more likely to have a primary care physician (PCP) (88% [337/381] versus 68% [13/19]), speak English natively (52% [199/381] versus 26% [5/19]), have a higher Charlson comorbidity index score, and identify as women (64.0% [244/381] versus 42.1% [8/19]). Having a PCP and native English language remained significant at multivariate analysis. Socioeconomic status score, quantity of contact information recorded at recruitment, and insurance status were not significantly associated with successful follow-up.

Conclusions: Patients engaged with the health care system by having a PCP are significantly more likely to achieve follow-up. Successful follow-up is also associated with native English speaking. The potential of improving follow-up by facilitating connections with health care providers requires further study.