title: Impact of an adherence intervention on the effectiveness of tenofovir gel in the CAPRISA 004 trial.
abstract: High adherence is important in microbicide trials, but no adherence interventions to date have demonstrated empiric improvements in microbicide adherence or effectiveness. Approximately midway during the CAPRISA 004 trial, we implemented a novel adherence intervention (Adherence Support Program-ASP), based on an Information-Motivation-Behavioral Skills model and incorporating a Motivational Interviewing approach. We assessed the impact of the ASP on adherence and tenofovir gel effectiveness using a before-and-after comparison. Of the 889 women in the trial, 774 contributed 486.1 women-years of follow-up pre-ASP and 828 contributed 845.7 women-years of follow-up post-ASP. Median adherence rose from 53.6 % pre-ASP to 66.5 % post-ASP. Detectable tenofovir levels increased from 40.6 % pre-ASP to 62.5 % post-ASP in 64 women who had paired tenofovir drug samples. Gel effectiveness improved post-ASP; HIV incidence in the tenofovir gel arm was 24 % lower pre-ASP compared to 47 % lower post-ASP. Following implementation of the ASP, microbicide adherence improved with a concomitant increase in the effectiveness of tenofovir gel.
authors.affiliation: Centre for the AIDS Programme of Research in South Africa, 2nd Floor, Doris Duke Medical Research Institute, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Private Bag X7, Congella, 4013, South Africa, mansoor@ukzn.ac.za.
authors.forename: Leila Essop
authors.initials: LE
authors.lastname: Mansoor
authors.forename: Quarraisha Abdool
authors.initials: QA
authors.lastname: Karim
authors.forename: Lise
authors.initials: L
authors.lastname: Werner
authors.forename: Bernadette
authors.initials: B
authors.lastname: Madlala
authors.forename: Nelisiwe
authors.initials: N
authors.lastname: Ngcobo
authors.forename: Deborah H
authors.initials: DH
authors.lastname: Cornman
authors.forename: K Rivet
authors.initials: KR
authors.lastname: Amico
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Fisher
authors.forename: William A
authors.initials: WA
authors.lastname: Fisher
authors.forename: Kathleen M
authors.initials: KM
authors.lastname: Macqueen
authors.forename: Salim S Abdool
authors.initials: SS
authors.lastname: Karim
mesh_terms: D000225:Adenine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000328:Adult; D019380:Anti-HIV Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D000891:Anti-Infective Agents, Local / Q000008:administration & dosage* / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005782:Gels; D015658:HIV Infections / Q000453:epidemiology / Q000517:prevention & control*; D015438:Health Behavior; D006801:Humans; D015994:Incidence; D055118:Medication Adherence / Q000523:psychology*; D008960:Models, Psychological; D062405:Motivational Interviewing; D063065:Organophosphonates / Q000008:administration & dosage*; D012959:Socioeconomic Factors; D013019:South Africa / Q000453:epidemiology; D000068698:Tenofovir; D016896:Treatment Outcome; D016903:Drug Monitoring
chemical_list: D019380:Anti-HIV Agents; D000891:Anti-Infective Agents, Local; D005782:Gels; D063065:Organophosphonates; D000068698:Tenofovir; D000225:Adenine