Incentivising safe sex: a randomised trial of conditional cash transfers for HIV and sexually transmitted infection prevention in rural Tanzania.
OBJECTIVE
The authors evaluated the use of conditional cash transfers as an HIV and sexually transmitted infection prevention strategy to incentivise safe sex.


METHODS
An unblinded, individually randomised and controlled trial.


METHODS
10 villages within the Kilombero/Ulanga districts of the Ifakara Health and Demographic Surveillance System in rural south-west Tanzania.


METHODS
The authors enrolled 2399 participants, aged 18-30 years, including adult spouses.


METHODS
Participants were randomly assigned to either a control arm (n=1124) or one of two intervention arms: low-value conditional cash transfer (eligible for $10 per testing round, n=660) and high-value conditional cash transfer (eligible for $20 per testing round, n=615). The authors tested participants every 4 months over a 12-month period for the presence of common sexually transmitted infections. In the intervention arms, conditional cash transfer payments were tied to negative sexually transmitted infection test results. Anyone testing positive for a sexually transmitted infection was offered free treatment, and all received counselling.


METHODS
The primary study end point was combined prevalence of the four sexually transmitted infections, which were tested and reported to subjects every 4 months: Chlamydia trachomatis, Neisseria gonorrhoeae, Trichomonas vaginalis and Mycoplasma genitalium. The authors also tested for HIV, herpes simplex virus 2 and syphilis at baseline and month 12.


RESULTS
At the end of the 12-month period, for the combined prevalence of any of the four sexually transmitted infections, which were tested and reported every 4 months (C trachomatis, N gonorrhoeae, T vaginalis and M genitalium), unadjusted RR for the high-value conditional cash transfer arm compared to controls was 0.80 (95% CI 0.54 to 1.06) and the adjusted RR was 0.73 (95% CI 0.47 to 0.99). Unadjusted RR for the high-value conditional cash transfer arm compared to the low-value conditional cash transfer arm was 0.76 (95% CI 0.49 to 1.03) and the adjusted RR was 0.69 (95% CI 0.45 to 0.92). No harm was reported.


CONCLUSIONS
Conditional cash transfers used to incentivise safer sexual practices are a potentially promising new tool in HIV and sexually transmitted infections prevention. Additional larger study would be useful to clarify the effect size, to calibrate the size of the incentive and to determine whether the intervention can be delivered cost effectively.


BACKGROUND
NCT00922038 ClinicalTrials.gov.
The World Bank, Development Research Group, Washington, District of Columbia, USA.
Damien
D
de Walque
William H
WH
Dow
Rose
R
Nathan
Ramadhani
R
Abdul
Faraji
F
Abilahi
Erick
E
Gong
Zachary
Z
Isdahl
Julian
J
Jamison
Boniphace
B
Jullu
Suneeta
S
Krishnan
Albert
A
Majura
Edward
E
Miguel
Jeanne
J
Moncada
Sally
S
Mtenga
Mathew Alexander
MA
Mwanyangala
Laura
L
Packel
Julius
J
Schachter
Kizito
K
Shirima
Carol A
CA
Medlin