Methodology

Geographical Scope of NDUS

  • NDUS is a nationwide survey and is being implemented as a combination of multiple, state specific surveys in the entire country.
  • The data collection activities of NDUS will be carried out in all States and Union Territories of the country and the survey will provide estimates of prevalence of substance use and substance use disorders for each district, each State/UT and the country as a whole.

Methodology of NDUS

The Use of psychoactive substances is a complex phenomenon. While certain substances are 'legal' and have more social acceptance (such as tobacco, alcohol, and to some extent, cannabis), others (such as opioids, stimulants, etc.) attracts both legal and social sanctions and hence, remains a relatively hidden phenomenon. Thus, a single methodological approach will be insufficient to study this multifaceted phenomenon in a large and diverse country like India. Consequently, NDUS uses a combination of different methodological approaches to study the drug use situation in India and provide precise estimates for the prevalence of use of various psychoactive substances in the country.

The methodological approaches being employed in NDUS are :

  • Household Sample Survey (HSS) is being conducted using a representative sample of the general population to determine the proportion of people who use substances and those suffering from substance use disorders. The HSS is being carried out in about 400 districts across all States and UTs of the country and includes both males and females in the age group of 10 to 75 years. Nationally, the HSS will cover more than 4,40,000 households, and approximately 17,60,000 individuals will be interviewed.
  • Respondent Driven Sampling (RDS) Survey (with multiplier) is being conducted among drug-dependent individuals to estimate the number of individuals dependent on various illicit substances. This survey is being carried out in about 350 districts across the country and includes male and female drug users above the age of 18 years. Nationally, the RDS survey will include interviews of more than 2,10,000 drug using individuals.
  • Focused Thematic Studies: NDUS includes in-depth studies on specific themes and population sub-groups, such as:
    • Assessment of pattern of drug use and vulnerability among PRISON POPULATIONS.
    • Study on pattern of use of rare and NEWER / RARER PSYCHOACTIVE SUBSTANCES.
    • Survey on alcohol and drug use among SCHOOL STUDENTS.
    • Survey on alcohol and drug use among COLLEGE / HIGHER EDUCATIONAL STUDENTS.
    • Survey documenting indigenous forms of substance use and associated socio-economic and health concerns.
    • Survey on accessibility and experience of using treatment services for substance use disorders.
    • Outcome of different types of treatment interventions.
    • Outcome of different types of educational / preventive interventions.
    • Enhancing credibility of self-report of drug use by laboratory technologies.
    • Exploring the feasibility of wastewater analysis to determine the trends of drug use in a locality.

The findings from the above mentioned survey methodologies will be collated to generate the national and state-level estimates for substance use disorders and to provide information on the profile of substance using individuals and the pattern of substance use.

Sampling Design for HHS component of NDUS

  • For the household sample survey, a uniform sampling design has been adopted in all the states/UTs of the country to ensure representativeness of the sample of households selected for the survey.
  • The sample has been drawn following a multi-stage sampling procedure which involves three stages:
  • Stage 1 - Selection of districts within a state
  • Stage 2 - Selection of primary sampling units (villages / wards) within a district
  • Stage 3 - Selection of households within primary sampling units (PSU).

Prior to the selection of households within a PSU, a Mapping and Listing of households will be carried out. The household listing provides up-to-date location and layout sketch maps of each selected PSU, which serve as the sampling frame for the selection of households.