A systematic review of the quality of trials evaluating biomedical HIV prevention interventions shows that many lack power.
OBJECTIVE
Several randomized, controlled trials (RCTs) have tested strategies to prevent sexual acquisition of HIV infection, but their quality has been variable. We aimed to identify, describe, and evaluate the quality of RCTs studying biomedical interventions to prevent HIV acquisition by sexual transmission.


METHODS
We conducted a systematic review to identify all RCTs evaluating the efficacy of biomedical HIV prevention interventions. We assessed seven generic and content-specific quality components important in HIV prevention trials, factors influencing study power, co-interventions provided, and trial ethics.


RESULTS
We identified 26 eligible RCTs. The median number of quality components judged to be in adequate or unclear was 3 (range 1-4) in 1992-1998, 3 (range 1-4) in 1999-2003, and 0 (range0-2) in 2004-2008 (p < .001). Common problems that may have biased results included low retention (median 84%), poor adherence to interventions requiring on going use (median < or =78%), and lower HIV incidence than expected a priori (in 8 of 11 trials where evaluable).


CONCLUSIONS
Reporting of trials of biomedical HIV prevention interventions has improved over time. However, quality improvement is needed in several key areas that influence study power, including participant retention, adherence to interventions, and estimation of expected HIV incidence.
Department of Medicine, University of Washington, Seattle, Washington, USA. grahamsm@u.washington.edu
Susan M
SM
Graham
Prakesh S
PS
Shah
Zoë Costa-von
ZC
Aesch
Joseph
J
Beyene
Ahmed M
AM
Bayoumi
D016915:AIDS Vaccines / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use; D002944:Circumcision, Male; D003274:Contraceptive Devices, Female; D005260:Female; D006678:HIV / Q000187:drug effects*; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control* / Q000821:virology; D006801:Humans; D015994:Incidence; D008297:Male; D010349:Patient Compliance; D010352:Patient Dropouts; D016032:Randomized Controlled Trials as Topic / Q000379:methods*; D012107:Research Design
D016915:AIDS Vaccines; D000890:Anti-Infective Agents