Evidence of the effectiveness of HIV antibody testing and counselling in altering behaviour is contradictory. A major review published in 1991 concluded that no reliable, controlled data existed to confirm the value of HIV testing as a prevention measure. Only amongst heterosexual couples was there any clear evidence that counselling and testing had any impact on the practice of safer sex. Amongst injecting drug users in contact with methadone maintenance programmes, HIV testing and counselling were associated with reductions in needle sharing, but there were no differences between those who tested positive or negative, suggesting that knowledge of HIV status was not the critical factor in encouraging safer behaviour (Higgins).

Amongst gay men there is no strong evidence that knowledge of HIV status in itself predisposes to safer sexual behaviour, although this has been inferred from a number of studies (Kippax).

All studies which have reported on the effects of testing and counselling have been uncontrolled, and it has been suggested that the self–selecting nature of such studies may bias the results, because those who come forward for testing may be more motivated to change their behaviour. However, testing may speed the process of behaviour change in the view of some commentators, and may act as a reinforcer of intentions regarding behaviour change, particularly if the practice of HIV testing receives social or peer support (Cohen).

Even if testing and counselling were proven to have a significant impact on subsequent behaviour, it is still questionable whether a successful intervention could be replicated by others. This is due to the subjective nature of the counselling encounter, which relies on the skills of the counsellor, the information content of the counselling session and the number of `doses'. SIGMA Research has shown wide variation in the content of counselling sessions and in their impact on individuals in the South–East of England, and there may be variations even within a counselling team. Recent research at the Chelsea and Westminster GUM clinic in London showed that significant divergences existed amongst both counsellors and clinicians regarding definitions of high, low and medium risk sex acts.

There is no guarantee that counselling interventions, even if they are standardised, will be received in similar ways by all clients. Critics of the Health Beliefs and Reasoned Action models of behaviour change have pointed out that social and peer pressures may act against `rational' assessment of information provided by counsellors, and that using HIV testing as a means of changing people's behaviour presupposes that people will act on the risk reduction information they are given (Beardsell).

References

Beardsell S et al. Should wider HIV testing be encouraged on the grounds of HIV prevention? AIDS Care 6: 1, 1994

Cohen M. Changing to safer sex: personality, logic and habit, in Aggleton P et al Eds: AIDS: Responses, interventions and care Falmer Press, London, 1991.

Higgins DL et al. Evidence for the effects of HIV antibody testing and counselling on risk behaviours, JAMA 226: 2419–2429, 1991.