Review of 14 rigorous studies to re-estimate condom effectiveness in reducing heterosexual transmission of HIV. Finds consistent condoms use results in an 80% reduction in HIV incidence, i.e 80% less than the particular act without condoms. Consistent use is defined as using a condom for all acts of penetrative vaginal intercourse.
Recent meta-analyses of condom effectiveness suggest that condoms are 60 to 70% effective when used for HIV prophylaxis. A re-examination of HIV seroconversion studies suggests that condoms are 90 to 95% effective when used consistently, i.e. consistent condom users are 10 to 20 times less likely to become infected when exposed to the virus than are inconsistent or non-users. Similar results are obtained utilizing model-based estimation techniques, which indicate that condoms decrease the per-contact probability of male-to-female transmission of HIV by about 95%.