Strategy uptake in included studies*
| Author, year | Intervention/s | Received recruitment intervention, n | Randomised to host RCT, n (%) | Statistical testing | Statistically significant? |
| Recruitment stage: Identification of participants | |||||
| Bhar et al, 201338 | Referrals from co-investigator’s Veteran’s Affairs mental health clinic | 63 | 24 (38) | ||
| Referrals from psychiatric outpatient clinic | 18 | 3 (17) | |||
| Mass mailing to primary care patients mailing list | 869 | 6 (1) | |||
| Referrals from inpatient psychiatric unit | 5 | 0 (0) | |||
| Referrals from primary care physicians | 0 | 0 (N/A) | NR | NR | |
| Chlebowski et al, 201040 | Mass mailing to male home owners | 60 000 | 600 (1) | ||
| Mass mailing to spouses of previous female research participants | 800 | 34 (4) | NR | NR | |
| Heiney et al, 201042 | Referral by physician | 24 | 13 (54) | ||
| Referral from previous health research study | 206 | 11 (5) | |||
| Mass mailing to oncology clinic list | 1384 | 15 (1) | |||
| Mass mailing to urology clinic list | 759 | 8 (1) | |||
| Mass mailing to support services department list | 350 | 2 (1) | |||
| Posters, newspaper articles, other | NR | 10 (N/A) | NR | NR | |
| Lee et al, 201145 | Mass mailing by post to former trial participants, health system users and commercial direct mailing lists | 34 064 | 143 (0.4) | ||
| Newspaper, radio and online advertising | NR | 129 (N/A) | |||
| Mass mailing by email to university employees, physicians, database of people interested in research | 35 000 | 31 (0.1) | |||
| Referral from urology clinic | 63 | 30 (48) | |||
| Posters and flyers | NR | 8 (N/A) | |||
| Other | NR | 28 (N/A) | NR | NR | |
| Recruitment stage: Participant information and consent | |||||
| Donovan et al, 200235 | Before: Not specified | 30 | NR (30–40) | ||
| After: Recruitment training and documentation informed by qualitative research | 155 | 108 (70) | NR | NR | |
| Donovan et al, 200349 | Recruitment visit conducted by urologist | 75 | 53 (71) | ||
| Recruitment visit conducted by nurse | 75 | 50 (67) | RD=4% (95% CI −10.8% to +18.8% p=0.60) | No | |
| Donovan et al, 200936 | Before: Standard recruitment training and documentation | NR | NR (69) | ||
| After: Recruitment training and documentation informed by qualitative research | NR | NR (65) | NR | NR | |
| Before: No site review | Centre A: 24 Centre B: 46 | Centre A: 11 (45) Centre B: 23 (50) | |||
| After: Recruitment-focused site review triggered by low performance | Centre A: 14 Centre B: 40 | Centre A: 12 (86) Centre B: 31 (78) | Centre A: p=0.020 Centre B: p=0.013 | Yes | |
| Eccles et al, 201334 | Standard study information at recruitment visit | 15 | 3 (20) | ||
| Decision aid video at recruitment visit | 15 | 1 (7) | NR | NR | |
| Wallace et al, 200650 | Before: one-on-one information session | 27 | 0 (0) | ||
| After: Multidisciplinary group information session | 263 | 32 (12) | NR | NR | |
| Recruitment stage: Multiple stages (Identification of participants, assessment of eligibility, participant information and consent) | |||||
| Ford et al, 200451 | Arm A: Enhanced mailed invitation, telephone screening by African-American interviewer, collection of baseline data by mail | 3079 | 78 (3) | Arm A v Arm D: p<0.01 | Yes |
| Arm B: Enhanced mailed invitation, telephone screening by African-American interviewer, collection of baseline data by phone | 3075 | 87 (3) | |||
| Arm C: Enhanced mailed invitation, telephone screening by African-American interviewer, collection of baseline data in person at church project session | 2949 | 116 (4) | |||
| Arm D (control): Standard mailed invitation, telephone screening by African-American or Caucasian interviewer, collection of baseline data by mail | 3297 | 95 (3) | Difference between arms B, C and D: p=0.66 | No | |
*Strategy uptake defined as the percentage of people receiving the recruitment intervention who went on to be randomised to the host RCT. Studies that did not report the number of participants receiving the recruitment intervention excluded. Poor quality studies excluded.
NR , not reported; RCT, randomised controlled trial; N/A, not applicable.