Table 1 Study design characteristics to support enrollment and retention of underrepresented minorities

Community interaction

Conducting study in safety net community clinics [29,30,31]

Working with community-based patient partners [13, 14, 18, 29, 32]

Partnering with community clinics [29, 30, 32]

Meeting with patients and stakeholders over course of study (study advisory board) [33,34,35,36,37,38]

Clinic interaction

Creating value for clinical care (e.g., providing test results to primary care clinicians) [13, 30, 33]

Providing education to clinic staff [33]

Payments to clinics [40]

Basing study activities at community clinics [37, 38, 40,41,42,43]

Patient interaction

Providing information to patient about their condition [13]

Bilingual staff and study materials [14, 18, 34]

Training research staff in outreach, recruitment and retention, especially for minority and underserved populations [45]

Recruitment

Face to face recruitment and enrollment when possible [8, 14]

Minimal inclusion/exclusion criteria [19]

Not requiring patient to endorse diagnosis of condition [14, 27]

Retention

Meeting with patient at home or close to where patient lived [14, 18]

Continuity of personal relationship with member of study team [8, 18, 46]

Maintaining contact at 3 month intervals [14, 44]

Both recruitment and retention

Flexibility in rescheduling meeting times [14, 18]

Providing compensation to patients [8, 13, 14, 27, 44]