Cost of recruitment strategies*
| Author, year | Costs reported | Recruitment phase | Intervention/s | Randomised, n | Cost | Cost per participant |
| Bhar et al, 201338 | Direct cost (stationary, postage, phone calls and catering) and indirect cost (staff time) | Identification of participants | Mass mailing—primary care patients mailing list | 6 | US$3813 | US$636 |
| Health services referral—co-investigator’s Veteran’s Affairs mental health clinic | 24 | US$1066 | US$44 | |||
| Health services referral—psychiatric outpatient clinic | 3 | US$497 | US$166 | |||
| Health services referral—primary care physicians | 0 | US$643 | N/A | |||
| Health services referral—inpatient psychiatric unit | 0 | US$519 | N/A | |||
| Chlebowski et al, 201040 | Mailing cost (not further specified) | Identification of participants | Mass mailing—male home owners | 600 | US$155 596 | US$259 |
| Mass mailing—spouses of previous female participant | 34 | US$2000 | US$59 | |||
| Donovan et al, 200349 | Salary and on-costs for staff time | Participant information and consent | Recruitment visit performed by urologist | 53 | NR | £43.29 |
| Recruitment visit performed by nurse | 50 | NR | £36.40 |
*Poor quality studies excluded.
NR, not reported.