RESUMO
Street children as a population sub-group exist in significant numbers in the developing world and have been reported to be vulnerable to adverse health and risk behaviours that include physical and sexual risk behaviour. However, the estimation of prevalence for various psychoactive substances among the street children in a representative sample has not been attempted in the developing country like India. This is challenging due to the absence of an appropriate sampling frame, the population living in isolation, hiding their identity and concealing their behaviour. Use of psychoactive substances in street children is riddled with these challenges. The present investigation describes the findings from size estimation study on a representative sample of street child (n = 766) in Delhi, by implementing the Respondent Driven Sampling Methodology (RDS). The weighted prevalence for three commonest substances was found as Tobacco (31.1 %), alcohol (13.5 %) and inhalants (11.3 %) used during the last one year with the estimated number as -Tobacco (21,770), Alcohol (9450) and Inhalants (5600). Almost one third of street children were using some substance. Also, a large majority of ever users were also using substances currently. The study demonstrates successfully the implementation of RDS for the estimation of the prevalence of psychoactive substances in a representative manner. A large majority of street children use psychoactive substances, and there is a need for more of such studies in other metropolitan cities so that local level interventions and planning can be done for treatment and prevention of psychoactive substances among the street children. The important public health implications had been discussed.