Table 1.
Study Outcomes and their definitions
| Outcome (at 2 years) 1 | Definition of outcome | Factor influencing efficiency of transmission | Factor reflecting exposure of susceptible to infected persons |
|---|---|---|---|
| Proportion of sexual acts involving a condom | Number of sex acts protected by a condom throughout divided by the number of sex acts in the last month2 | √ | |
| Condom use at last sex | At last sex, use of condom throughout | √ | |
| Unsafe sex | Inconsistent condom use with a HIV-negative or unknown serostatus partner in the past 6 months | √ | √ |
| Sexually active | One or more sex acts in the last month | √ | |
| Frequency of sex acts within each partnership | The number of sex acts with each partner in the last month | √ | |
| Rates of acquisition of new sex partners | The number of new partnerships in the last 6 months divided by the person years of follow-up in the last 6 months | √ | |
| Rates of dissolution of existing partnerships | The number of partnerships ended in the last 6 months divided by the person years of follow-up in partnership in the last 6 months | √ | |
| Frequency of concurrent partnerships | Number of overlapping sexual partnerships in which sexual intercourse with one partner occurs between two acts of intercourse with another partner3 | √ | |
| Abstinence | No sexual intercourse during the past 6 months | √ | |
1 Analyses of these outcomes will also be conducted at earlier time-points.
2 Information is collected in the last month; however, if there was no sex in the last month, the questions are asked about the last 3 months; and if no sex in the last 3 months, the questions are asked about the last 6 months
3 UNAIDS Reference Group on Estimates, Modelling, and Projections: Working Group on Measuring Concurrent Sexual Partnerships. HIV: consensus indicators are needed for concurrency. Lancet. 2010 Feb 20;375(9715):621-2.