Study population and sampling strategy

LASI’s baseline wave (Wave 1) from 2017 to 2019 represents all 35 states and union territories in India. Over 72,000 adults were sampled, with individuals aged 45 and older and their spouses (regardless of age) residing in households interviewed. A LASI-eligible household has at least one member aged 45 or older. Respondents and their households will be followed-up over a period of 25 years.

The LASI sample is based on the multistage stratified cluster sample design, which includes three distinct selection stages in rural areas and four distinct selection stages in urban areas. To obtain more reliable estimates, LASI also oversamples the 65 years and older population in all the secondary sampling units (SSUs) and around 1,000 respondents from 4 major cities: Chennai, Delhi, Kolkata, and Mumbai.

LASI Instruments

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Responses from the participants are collected through face-to-face interviews using computer-assisted personal interviewing (CAPI). The LASI instrument consists of three surveys:

1. Household Survey Schedule

  • The survey is administered once per eligible LASI household.
  • It covers the following sections: Household Roster; Housing and Environment; Household Consumption; Household Assets and Debts; Household Income; and Household Health Insurance.

2. Individual Survey Schedule

  • The survey is administered to all respondents aged 45 years and older and their spouses in Wave 1 households.
  • It covers the following sections: Demographics; Work, Retirement, and Pension; Health and Cognition; Healthcare Access and Utilization; Family and Social Networks; Experimental Modules; and Biomarkers.

3. Community Survey Schedule

  • The survey is administered to key informants at the community level in both urban and rural areas.
  • It covers the following sections: Population Characteristics; Infrastructure and Common Resources; Accessibility and Availability of Healthcare Services; and Coverage of Health and Social Welfare Programs.
The LASI Diagnostic Assessment of Dementia (LASI-DAD) is an in-depth study of late-life cognitive impairment and dementia risk. It draws a sub-sample of 4,000+ LASI Wave 1 respondents aged 60 years and older and their family members. More information regarding this study can be accessed here .