HIV prevention programmes & new interventions for truckers in India.

Sir,

We read with interest the article on willingness of truckers for new HIV interventions published in the June 2013 issue1.

The study provides a useful insight into the willingness for newer interventions for HIV prevention among truckers. The study also included helpers in the sample, which is commendable since this group has so far been excluded from certain large scale surveys like the Integrated Behavioural and Biological Assessment survey2, even though they endure similar working conditions as drivers. However, we would like to raise certain issues which concerned us.

The authors have used prevalence of HIV as 6 per cent for sample size calculation based on a previous study3. However, on perusal of the quoted reference, the overall prevalence of HIV reported was 1.72 per cent and that among men in a transport related occupation was 4.79 per cent. Also, the said study was conducted among the general population of Guntur district of Andhra Pradesh. Thus, the use of these findings to calculate sample size in the context of truckers is questionable.

The authors have mentioned that the number of truckers selected from each halt point was proportional to the number of trucks estimated to be present at each point, using a systematic random sampling method. If so, since the total number of truckers at each point would vary, the sampling interval at each point should have been chosen based on that number and the numbers of truckers required at that point; and not restricted to every 3rd or 5th truck as has been mentioned in the study.

The method used to select one trucker from each truck is not mentioned. The rationale behind selecting drivers and truckers in a 2:1 ratio is also not explained. Similarly, the reason behind exclusion of trucks belonging to N3 (mass above 12 tonnes) category is not clear. Including ability to converse in one of three languages, i.e. English, Hindi and Telugu, as a criterion for selection into the study might have led to the exclusion of truckers belonging to States like Tamil Nadu and Karnataka (as is evident from the results section, which shows a very low proportion of truckers belonging to these States). This might be the reason for very low contact with HIV prevention services observed in the study. This is further supported by the fact that Targeted Interventions in Tamil Nadu were known to have a good coverage of bridge population like truckers at the time of the conduct of the study4. These findings bring in the question of selection bias which has not been addressed as limitations and thus cast doubts on whether the results could be generalized to the whole of south India, as claimed by the authors in the discussion section. The low contact with HIV prevention programme reported might have also resulted from social desirability bias, as the information was gathered using direct interviews.

Multiple logistic regression analysis was carried out to find various associations and to arrive at adjusted odds ratios. It would have been more relevant to report the P values arrived at through the multiple logistic regression analyses, instead of performing Chi square tests for each of the variables (Tables II and III in the study)1.

The categorization of some of the variables in Table III is not clear, e.g in Table III, working for 5 years and age 30 years falls in neither of the categories mentioned.

It was also important to understand the characteristics of truckers willing for other newer interventions apart from circumcision (information not provided). One of the important variables which should have been reported is the economic background of the truckers, as this would have had a huge impact on the willingness to pay.

In the discussion of results, two studies are quoted for having reported high acceptability of oral HIV testing in the high risk group of female sex workers (FSWs). However, neither of these pertains to FSWs: one of the studies was conducted among women admitted in a labour ward and the other is an editorial on applicability of oral HIV testing in developing countries56.