Optimizing enrollment methods: Lessons learned from an mHealth, pilot HIV prevention randomized controlled trial with sexual minority men.

Using data from eligible participants, we evaluated procedures of a multi-step enrollment process for an mHealth, pilot randomized controlled trial aimed to promote regular HIV testing among at-risk, diverse sexual minority men. Completion rates of eligible participants were calculated and characterized for these enrollment procedures. Among 3058 men who screened, 183 were eligible and 113 enrolled. Two groups emerged: "As planned" (n = 98) followed enrollment directions as designed; "Laggers" (n = 15) did not follow these directions and required additional efforts resulting in mixed results for improving enrollment. Findings suggest the need for pre-determined enrollment decision rules based on available resources.