No doubt should be cast on efficacy of cognitive behavioural interventions

EDITOR—We applaud Imrie et al for conducting a rigorous, randomised clinical trial to reduce sexually transmitted infections in gay men.1 We have, however, concerns about the conclusions drawn from this comparatively small scale study to all cognitive behavioural interventions.

Firstly, to see changes in sexually transmitted infections as a result of an intervention, we need to see changes in safer sexual behaviours, such as increased use of condoms. The trials reported by Imrie et al did apparently not produce significant changes in safer sexual behaviour. Therefore, it was to be expected that no changes in the incidence of sexually transmitted infections were seen either.

Secondly, the fact that this trial was apparently not successful should not cast any doubt on the efficacy of cognitive behavioural interventions. Other, much larger, cognitive behavioural trials carried out with high risk populations in the United States and Thailand have been effective.2^–4 Effectiveness has been shown not only by increases in use of condoms, but by decreases in sexually transmitted infections and incidence of HIV in some trials. 2 4

Thirdly, it is not yet known what smallest “dose” of an intervention of this type will produce sustained effects. But the likelihood that an intervention of one session would be successful is quite small. Although brief interventions have been successful in other areas, they have not been successful in changing sexual behaviour.5 Furthermore, at least one study has shown a dose-response relation between …