What about money? Effect of small monetary incentives on enrollment, retention, and motivation to change behaviour in an HIV/STD prevention counselling intervention. The Project RESPECT Study Group

OBJECTIVES: We studied the effect of small monetary incentives and non-monetary incentives of similar value on enrollment and participation in clinic based HIV/STD prevention counselling. We examined incident STDs to try to assess whether participants offered money may be less motivated to change risky behaviours than those offered other incentives. METHODS: Patients from five US STD clinics were invited to enroll in a multisession risk reduction counselling intervention and, based on their enrollment date, were offered either $15 for each additional session or non-monetary incentives worth $15. The two incentive groups were compared on participants' enrollment, completion of intervention sessions, and new STDs over the 24 months after enrollment. RESULTS: Of 648 patients offered money, 198 (31%) enrolled compared with 160 (23%) of 696 patients offered other incentives (p = 0.002). Enrollees in the two incentive groups had similar baseline characteristics, including condom use. Of the 198 participants offered money, 109 (55%) completed all sessions compared with 59 (37%) of the participants offered other incentives (p < 0.0001). Comparing those offered money with those offered other incentives STD rates were similar after 6, 12, and 24 months. CONCLUSIONS: Small monetary incentives enhanced enrollment and participation compared with other incentives of similar value. Regardless of incentive offered, participants had similar post-enrollment STD rates, suggesting that the type of incentive does not adversely affect motivation to change behaviour. Money may be useful in encouraging high risk individuals to participate in and complete counselling or other public health interventions.