The authors found 35 studies, which were divided into four study populations. Each of the studies was required to provide either an evaluation of HIV CT in a longitudinal design assessing behaviour prior to and following HIV CT, or evaluation of HIV CT in a cross-sectional design comparing groups of patients with different HIV CT histories or outcomes.
The first group, MSM, had 2,984 participants in 7 studies: 4 cross-sectional, 1 longitudinal, and 2 longitudinal with cross-sectional data analysis.
The second group, IUD, had 7,161 participants in 9 studies: 5 cross-sectional, 2 longitudinal, and 2 longitudinal with cross-sectional data analysis.
The third group, women and heterosexual couples, had 7,627 participants in 12 studies: 1 cross-sectional, 4 longitudinal, and 7 longitudinal with cross-sectional data analysis.
The fourth group, mixed population, had 4,398 participants in 7 studies: 1 cross-sectional, 3 longitudinal, 2 records review, and 1 randomised controlled trial.
MSM group: the studies documented a substantial risk-related behaviour change among MSM, but did not provide consistent evidence regarding the effects of HIV CT on sexual risk practices. Similarly, although studies addressing help-seeking behaviour found significant differences between HIV-seronegative and HIV-seropositive men, these differences may in some cases be related to symptomatic disease progression and not HIV CT.
IDU group: most of the studies found some beneficial behaviour changes among IDUs and other drug users who received HIV CT. The beneficial impact of HIV CT was observed for both drug-related and sexual practices. HIV-seropositive drug users were generally most likely to engage in reduced-risk practices following HIV CT, than were HIV-seronegative or untested IDUs. The single study of help-seeking behaviour following HIV CT failed to find significant differences in the use of medical services between HIV-seronegative and HIV-seropositive IDUs with one or no HIV-related symptoms.
Women and heterosexual couples group: the studies found mixed results. Of 4 studies examining the impact of HIV CT on pregnancy rates, 2 found knowledge of serostatus to be unrelated to pregnancy, whilst the other 2 found that women who learned they were HIV-seropositive were significantly less likely to become pregnant than their HIV-seronegative peers. Two studies also reported inconsistent findings concerning the relationship of HIV CT to pregnancy termination, and others provided mixed results concerning the impact of HIV CT on condom use and other birth control methods. Two studies reported no impact of HIV CT on composite risk behaviour scores; however, the studies of HIV-serodiscordant couples reported substantial increases in condom use following HIV CT in some circumstances. None of these studies addressed the impact of HIV CT on help-seeking behaviour.
Mixed population group: 3 of the 4 studies that included only HIV-seropositive individuals found evidence indicating that HIV CT was associated with reductions in sexual risk-related practices among individuals who knew they were HIV infected. Studies in which all or the majority of participants were HIV seronegative provided little consistent evidence regarding the behavioural effects of HIV CT.