Recruitment strategies and challenges in a large intervention trial: Systolic Blood Pressure Intervention Trial

Abstract

Background The Systolic Blood Pressure Intervention Trial (SPRINT) is a multicenter, randomized clinical trial of 9,361 participants with hypertension who are ≥ 50 years old. The trial is designed to evaluate the effect of intensive systolic blood pressure control (systolic blood pressure goal <120 mm Hg) compared to standard control (systolic blood pressure goal <140 mm Hg) on cardiovascular events using commonly prescribed antihypertensive medications and lifestyle modification. Objective To describe the recruitment strategies and lessons learned during recruitment of the SPRINT cohort and five targeted participant subgroups: pre-existing cardiovascular disease, pre-existing chronic kidney disease, age ≥ 75 years, women, and minorities. Methods In collaboration with the National Institutes of Health Project Office and SPRINT Coordinating Center, five Clinical Center Networks oversaw clinical site selection, recruitment, and trial activities. Recruitment began November 8, 2010 and ended March 15, 2013 (about 28 months). Various recruitment strategies were used, including mass mailing, brochures, referrals from healthcare providers or friends, posters, newspaper ads, radio ads, and electronic medical record searches. Results Recruitment was scheduled to last 24 months to enroll a target of 9,250 participants; in just over 28 months, the trial enrolled 9,361 participants. The trial screened 14,692 volunteers, with 33% of initial screens originating from the use of mass mailing lists. Screening results show that participants also responded to recruitment efforts through referral by SPRINT staff, healthcare providers, or friends (45%); brochures or posters placed in clinic waiting areas (15%); and television, radio, newspaper, internet ads, or toll-free numbers (8%). The overall recruitment yield (number randomized /number screened) was 64% (9,361 randomized /14,692 screened), 77% for those with cardiovascular disease, 79% for those with chronic kidney disease, 70% for those age ≥ 75 years, 55% for women, and 61% for minorities. As recruitment was observed to lag behind expectations, additional clinics were included and inclusion criteria were broadened, keeping event rates and trial power in mind. As overall recruitment improved, a greater focus on subgroup recruitment was implemented. Conclusion SPRINT met its overall projected recruitment goal by using diverse, locally adapted enrollment strategies to specifically target persons with cardiovascular disease, chronic kidney disease, ≥ 75 year old, women, and minority subgroups. The trial exceeded its recruitment goal for minorities but found it a challenge to meet the competing demands of the targeted goals for recruiting into the remaining four subgroups. Important lessons include the imperative to monitor the recruitment process carefully, decide early to add new clinics or modify inclusion and exclusion criteria if recruitment lags, and consider limiting enrollment to subgroups only. We found benefit in using multiple recruitment sources simultaneously...

Strategies for recruiting a sample of adults with type 2 diabetes from primary care clinics in rural Appalachia: Incorporating cultural competence

“…In another study, Ramsey and colleagues [42] used multiple strategies, including mailing, media, posters, brochures, and referrals from clinic staff. They recruited a sample of over 9000 people, with over 45% being referred from either study staff, clinic personnel, or friends.…”

Achieved systolic blood pressure in older people: a systematic review and meta-analysis

“…Moreover, trials including a larger number of participants and with a longer follow-up period could correct power issues observed in previous trials and provide important information regarding serious adverse events. Three trials are currently recruiting participants to analyse the impact of different SBP levels <150 mmHg in cardiovascular outcomes [ 16 , 18 , 36 ]. Two will evaluate participants with previous stroke [ 16 , 18 ] and one will provide information for the general population [ 36 ].…”

“…Three trials are currently recruiting participants to analyse the impact of different SBP levels <150 mmHg in cardiovascular outcomes [ 16 , 18 , 36 ]. Two will evaluate participants with previous stroke [ 16 , 18 ] and one will provide information for the general population [ 36 ]. These studies may help clarify whether older people with different cardiovascular risk profile might benefit from different SBP levels.…”

<p>A Community and Technology-Based Approach for Hypertension Self-Management (COACHMAN) to Improve Blood Pressure Control in African Americans: Results from a Pilot Study</p>

“…Participants were recruited from the hospital and affiliated community clinics at UHCMC, as well as from community outreach and engagements using various recruitment methods. [30][31][32] Participants were eligible for this study if they (1) self-identified as African American, (2) were 30 years of age or older, (3) had been diagnosed with hypertension (BP >140/90 mmHg) and prescribed an antihypertensive drug, (4) were able to read/understand English, and (5) owned a smartphone. Individuals were excluded if they had a history of cognitive impairment or recent hospitalization or emergency department visit related to hypertension.…”