TY - JOUR
T1 - Adherence to Antiretroviral Prophylaxis for HIV Prevention
T2 - A Substudy Cohort within a Clinical Trial of Serodiscordant Couples in East Africa
AU - Haberer, Jessica E.
AU - Baeten, Jared M.
AU - Campbell, James
AU - Wangisi, Jonathan
AU - Katabira, Elly
AU - Ronald, Allan
AU - Tumwesigye, Elioda
AU - Psaros, Christina
AU - Safren, Steven A.
AU - Ware, Norma C.
AU - Thomas, Katherine K.
AU - Donnell, Deborah
AU - Krows, Meighan
AU - Kidoguchi, Lara
AU - Celum, Connie
AU - Bangsberg, David R.
PY - 2013/9
Y1 - 2013/9
N2 - Background:Randomized clinical trials of oral antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention have widely divergent efficacy estimates, ranging from 0% to 75%. These discrepancies are likely due to differences in adherence. To our knowledge, no studies to date have examined the impact of improving adherence through monitoring and/or intervention, which may increase PrEP efficacy, or reported on objective behavioral measures of adherence, which can inform PrEP effectiveness and implementation.Methods and Findings:Within the Partners PrEP Study (a randomized placebo-controlled trial of oral tenofovir and emtricitabine/tenofovir among HIV-uninfected members of serodiscordant couples in Kenya and Uganda), we collected objective measures of PrEP adherence using unannounced home-based pill counts and electronic pill bottle monitoring. Participants received individual and couples-based adherence counseling at PrEP initiation and throughout the study; counseling was intensified if unannounced pill count adherence fell to <80%. Participants were followed monthly to provide study medication, adherence counseling, and HIV testing. A total of 1,147 HIV-uninfected participants were enrolled: 53% were male, median age was 34 years, and median partnership duration was 8.5 years. Fourteen HIV infections occurred among adherence study participants-all of whom were assigned to placebo (PrEP efficacy = 100%, 95% confidence interval 83.7%-100%, p<0.001). Median adherence was 99.1% (interquartile range [IQR] 96.9%-100%) by unannounced pill counts and 97.2% (90.6%-100%) by electronic monitoring over 807 person-years. Report of no sex or sex with another person besides the study partner, younger age, and heavy alcohol use were associated with <80% adherence; the first 6 months of PrEP use and polygamous marriage were associated with >80% adherence. Study limitations include potential shortcomings of the adherence measures and use of a convenience sample within the substudy cohort.Conclusions:The high PrEP adherence achieved in the setting of active adherence monitoring and counseling support was associated with a high degree of protection from HIV acquisition by the HIV-uninfected partner in heterosexual serodiscordant couples. Low PrEP adherence was associated with sexual behavior, alcohol use, younger age, and length of PrEP use.Please see later in the article for the Editors' Summary.
AB - Background:Randomized clinical trials of oral antiretroviral pre-exposure prophylaxis (PrEP) for HIV prevention have widely divergent efficacy estimates, ranging from 0% to 75%. These discrepancies are likely due to differences in adherence. To our knowledge, no studies to date have examined the impact of improving adherence through monitoring and/or intervention, which may increase PrEP efficacy, or reported on objective behavioral measures of adherence, which can inform PrEP effectiveness and implementation.Methods and Findings:Within the Partners PrEP Study (a randomized placebo-controlled trial of oral tenofovir and emtricitabine/tenofovir among HIV-uninfected members of serodiscordant couples in Kenya and Uganda), we collected objective measures of PrEP adherence using unannounced home-based pill counts and electronic pill bottle monitoring. Participants received individual and couples-based adherence counseling at PrEP initiation and throughout the study; counseling was intensified if unannounced pill count adherence fell to <80%. Participants were followed monthly to provide study medication, adherence counseling, and HIV testing. A total of 1,147 HIV-uninfected participants were enrolled: 53% were male, median age was 34 years, and median partnership duration was 8.5 years. Fourteen HIV infections occurred among adherence study participants-all of whom were assigned to placebo (PrEP efficacy = 100%, 95% confidence interval 83.7%-100%, p<0.001). Median adherence was 99.1% (interquartile range [IQR] 96.9%-100%) by unannounced pill counts and 97.2% (90.6%-100%) by electronic monitoring over 807 person-years. Report of no sex or sex with another person besides the study partner, younger age, and heavy alcohol use were associated with <80% adherence; the first 6 months of PrEP use and polygamous marriage were associated with >80% adherence. Study limitations include potential shortcomings of the adherence measures and use of a convenience sample within the substudy cohort.Conclusions:The high PrEP adherence achieved in the setting of active adherence monitoring and counseling support was associated with a high degree of protection from HIV acquisition by the HIV-uninfected partner in heterosexual serodiscordant couples. Low PrEP adherence was associated with sexual behavior, alcohol use, younger age, and length of PrEP use.Please see later in the article for the Editors' Summary.
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U2 - 10.1371/journal.pmed.1001511
DO - 10.1371/journal.pmed.1001511
M3 - Article
C2 - 24058300
AN - SCOPUS:84884634016
SN - 1549-1277
VL - 10
JO - PLoS Medicine
JF - PLoS Medicine
IS - 9
M1 - e1001511
ER -