Epidemiology of dependence on illicit substances, with a special focus on opioid dependence, in the State of Punjab, India: Results from two different yet complementary survey methods.

Background: We used two different yet complementary methods to capture the 'hidden population' of illicit substance users in the state of Punjab, India: Rapid Assessment Survey (RAS) and Punjab Drug Use Monitoring Survey (P-DUMS).

Methodology: For the RAS component, following a pilot study, Respondent Driven Sampling was used to recruit 6600 community-dwelling substance dependent persons aged 11-60 years from all the 22 districts of Punjab. Size was estimated using benchmark-multiplier method, and prevalence was calculated by projecting these data to the source population. For the P-DUMS component, data were collected on 7421 inpatients from 75 government de-addiction centres from 19 districts of Punjab.

Results: Subjects In both RAS and P-DUMS were primarily opioid dependent (88% in RAS and 83% in P-DUMS). Heroin (inhaled/injected) emerged as the commonest opioid in both RAS (46%) and P-DUMS (52%), though 30.5% of the RAS sample also used the prescription opioid tramadol. Using the benchmark-multiplier method, 0.27 million (2.5% of the source population) were estimated to be opioid dependent, of which nearly 78,000 (0.7% of the source population) were injecting opioid users (IDUs), predominantly heroin (62%) but also buprenorphine (32.5%). High-risk behaviour was reported by nearly 60% of IDUs. Only 14% of the RAS sample had ever visited any de-addiction centre, and only 2.8% individuals had been admitted to a de-addiction centre in the past year.

Conclusion: There is a substantive problem of opioid dependence in this difficult-to-reach population of Punjab, with low treatment access. Misuse of prescription opioids along with IDU also raises concern.