Core Group 1: Number of sexual partners in the last 12 months

toolkit material

Title and definition: 1. Number of sexual partners in the last 12 months


Purpose and rationale  To assess the proportion of people who have multiple partners (sequentially or concurrently), in the last 12 months and the median/ mean number of partners in the last 12 months in a population
Method of measurement

Respondents are asked whether or not they have ever had sexual intercourse and, if yes, they are asked: “In the last 12 months, how many different people have you had sexual intercourse with”

Numerator: Number of respondents who have had sexual intercourse with more than one partner in the last 12 months

Denominator: Number of  respondents

Collection method  Population-based surveys in the general population and young people, population–based or  convenient samples in specific populations such as MSM, IDU, SW
Measurement frequency   Every 4-5 years in the general population and in young people; more frequently in higher risk populations; context-dependent
 Details of Disaggregation The indicator should be presented separately for males and for females; it should be disaggregated: in the general population by the age groups 15–19, 20–24 and 25–49, 50+ years; in specific populations (MSM, IDU, SW), by. <25, 25+.
Guidelines on how to interpret changes in the indicator 

This indicator gives a picture of levels of higher-risk sex. If people have only one sexual partner, the change will be captured by changes in this indicator. However, if people simply decrease the number of sexual partners they have, the indicator will not reflect a change, even though potentially this may have a significant impact on the epidemic spread of HIV and may be counted a programme success. Mean/median number of partners in the last 12 months can capture the latter, especially in populations with higher numbers of partners (e.g. MSM).

Accessing and/or surveying populations at highest risk can be challenging. Consequently, data obtained may not be based on a representative sample of the national population at highest risk being surveyed. If there are concerns that the data are not based on a representative sample, these concerns should be reflected in the interpretation of the survey data. Where different sources of data exist, the best available estimate should be used. Information on the sample size, the quality and reliability of the data, and any related issues should be included in the report submitted with this indicator. Tracking populations at highest risk over time to measure progress may be difficult due to mobility and the hard-to-reach nature of these populations with many groups being hidden populations. Thus, information about the nature of the sample should be reported in the narrative to facilitate interpretation and analysis over time.

Strengths and weaknesses The indicator may give a picture of higher-risk sex in the general population and tracking it can assist in monitoring behaviour change.Recall bias in persons with multiple partners. This indicator does not distinguish between multiple serial monogamy versus partner concurrency, each of which have different potentials for HIV spread through sexual networks.
Additional sources of information  

Allows for construction of UNGASS indicator No. 16 . « Higher–risk sex »: percentage of women and men aged 15-49 who have had sexual intercourse with more than one partner in the last 12 months. See this Guidelines on contruction of core indicators from the United Nations General Assembly Special Session on HIV/AIDS