6.2 Behavioural data collection in a low-level epidemic

In low-level epidemics, the risk of HIV infection is likely to be concentrated among those with higher levels of risk behaviour in a country. Depending on the country, these might include sex workers and their clients, drug injectors, men who have sex with men, or other populations. In this type of epidemic, it is recommended that HIV prevalence studies also focus on those with higher-risk behaviours. Risk behaviour may exist in the general population, however, and the links between higher- and-lower risk populations need to be investigated.

Many countries with low-level epidemics have not felt the need to invest resources in collecting behavioural data, assuming that if the virus is largely absent, risk behaviour must be limited. However, it is exactly at this point of the epidemic that behavioural data can act most effectively as a warning system. Where behavioural data and other indicators such as STD or hepatitis B prevalence show that people are having unprotected sex with multiple partners or are sharing injecting equipment, it may simply be a matter of time before HIV follows.

Collecting information on behaviour at this stage spotlights potential flash points for HIV infection. It can raise awareness among the public and among policymakers of the dangers posed by not doing anything to keep the virus confined at low levels, and it can help suggest what must be done, and for whom.

Preliminary assessment: identifying risk behaviours

This first step in the preliminary assessment might be described as the "homework" stage of data collection. It provides a preliminary picture of what is already known about risk behaviour in a country. This involves gathering all existing studies, published and unpublished, trawling through press reports and other sources of anecdotal information, and speaking to people likely to have information on sexual and drug-taking behaviour. In most countries, such research will provide enough information to identify the behaviours more likely to spread HIV and to characterise the individuals or groups that are more likely to engage in those behaviours. There are very few countries where all high-risk behaviours are equally represented; therefore, behavioural data collection should focus on those more likely to be driving the epidemic in a given country.

In many countries this information on risk behaviour will already be available as part of the analysis of epidemiological data on HIV/AIDS reporting or of a situation assessment carried out as part of a strategic planning exercise. Occasionally, this review will point to gaps in existing information about the epidemic that must be filled with basic anthropological research. Where no information exists and risk behaviours must be identified from scratch, the research may take up to three months.

Preliminary assessment: quantifying populations with higher risk

Behavioural data collection in a low-level epidemic will focus oil populations with higher levels of risk behaviour. These populations must be quantified if representative data are to be collected. This generally involves a mapping of sites where the behaviours take place, such as brothels, shooting galleries, gay bars, and cruising areas, together with an estimate of the number of individuals associated with each site.

Preliminary assessment: examining links with the general population

The data needed to plan effective HIV prevention programmes in a low-level epidemic will depend on how much individuals and communities with higher levels of risk interact with those with lower risk. Qualitative research - in-depth and key informant interviewing and perhaps focus group discussions - among people with higher risk can help identify interactions with the general population. In using the term "general population" we recognise that it is a composite of many subpopulations and that people at higher risk are part of the overall general population. Accordingly, where these links are widespread, the behavioural data collection system must include general population surveys. This is most often the case where commercial sex is common, but the need may also arise where men frequently have sex with both men and women or where drug injectors are sexually active with people who do not use drugs.

Qualitative research can be as costly and time-consuming as a quantitative survey. Sample sizes are therefore small, and results may not be representative of the total source population. However, this type of research provides essential input for the design of survey questionnaires that will yield relevant, informative, and actionable data from a larger population sample. It may also provide information that will inform the sampling process. Therefore, qualitative research is an essential requirement for the design of appropriate prevention programmes.

Behavioural monitoring: populations with higher-risk behaviours

Once the populations with higher levels of risk behaviour have been) identified and quantified, behaviour can be surveyed and risk quantified. Using random probability sampling or other sampling methods and a sampling frame constructed during the mapping process, a behavioural survey provides information that is representative or close to representative for the group in question. It acts as a baseline and can be repeated using identical sampling methods to measure change over time. The sample size will vary depending upon the population size and the frequency of the behaviours to be measured. Generally, sample sizes will fall between 250 and 400 respondents.

It is assumed that the data provided by baseline surveys will be used to design and promote programmes that aim to reduce risk behaviour. The frequency of subsequent survey rounds is recommended to be at least every other year but will at this stage depend on the nature of the programmes intended to benefit the survey population. The first round of data collection will always be the most costly and time consuming, as it involves training and concentrated work on a sampling frame. Collecting and analyzing the data for single round of a behavioural survey in selected population groups may take between three and six months, depending on the number of target populations and survey areas.

Some groups with higher levels of risk behaviour may be impossible to sample in a systematic and replicable way, or in numbers great enough to provide significant results. For these groups, ad hoc surveys linked to prevention programmes are recommended. Programmes aimed at changing behaviour in such groups should in any case have a component built in to monitor change over time; these evaluation techniques can be a useful addition to a broader behavioural data collection system.

Data on HIV prevalence in these groups should be collected on a voluntary basis with informed consent as part of service provision.

Behavioural monitoring: general population

The qualitative research will reveal links between populations with higher levels of risk behaviour and the general population. If they appear widespread, then a household-based survey of the general population is needed to determine what proportion of the population is at risk of acquiring HIV infection through contact with subpopulations more likely to be infected.

It is worth noting that this contact may shift over time in response to the epidemic itself General population data may therefore provoke a revision of groups included in targeted survey systems. For example, men in general population surveys in Thailand reported a reduction in brothel-based sex but an increase in commercial sex with hostesses in restaurants and bars. Such a shift may require a remapping of the populations with higher levels of risk behaviour and construction of a new sampling frame for targeted behavioural surveys.

Table 4: BEHAVIOURAL DATA NEEDS AND METHODS IN A LOW-LEVEL EPIDEMIC

*DURATION: Includes all research or survey stages from preparatory work to the production of findings.

Household-based population surveys are a great asset in building support for HIV prevention activities among policymakers and the general public, especially when they demonstrate that behaviour has changed following past prevention efforts. It is therefore recommended that, where there are clear links between the general population and those with higher-risk behaviour, general population surveys be earned out every four to five years. It may be possible to reduce the cost of these surveys drastically by adding appropriate questions on sexual behaviour to existing household survey rounds, but the particular sensitivities of the topic must be considered. For example, interviewers in general health survey rounds may need extra training before asking questions about sexual behavior