Table 1 Description of the other factors included in the study, Longitudinal Aging Study (LASI) Wave 1, India 2017–18

Age

Young-old (60–69 years)

Age of the respondents were available in "young-old (60–69 years)," "old-old (70–79 years)," and "oldest-old (80 years & above)" [31]

old-old (70–79 years)

oldest-old (80 years & above)

Sex

Male

Sex of the respondent was available in male–female categories [26]

Female

Place of residence

Rural

Place of residence (rural/urban) was determined according to the administrative division of India followed in Census of India, 2011. Households in urban areas included those in towns, wards and Census Enumeration Blocks whereas, households in rural areas include those in villages (size varies from 0–10,000 population [32]

Urban

Education

No education/ primary not completed

There were four categories for educational status: No education/ primary not completed," "Primary," "Secondary," and "Higher" [33]

Primary

Secondary

Higher

Religion

Hindu

Religion was categorized into Hindu, Muslim, Christian, and others [34]

Muslim

Christian

Others

Caste

Scheduled castes (SC)

Caste was coded as Scheduled castes (SC), Scheduled Tribes (ST), Other Backward Class (OBC) and others. SC and ST are India's most economically and socially disadvantaged groups. According to the Hindu caste system, the ST contains a segment of the population that is socially isolated and has a low economic position. People who were "educationally, economically, and socially backward" are classified as OBC. In the old caste order, the OBC is seen as being at the bottom yet somewhat above the most disadvantaged communities. The “other” caste category is identified as those having higher social standings [35]

Scheduled Tribes (ST)

Other backward classes (OBC)

Others

Health and behavioural factors

 ADL disability

Yes

In the individual schedule, ADL consists of difficulties with six activities related to dressing which include putting on chappals or shoes, walking across a room, difficulties in bathing, eating, getting in or out of bed, and using the toilet, including getting up and down. Further, combining these six ADLs into one variable, we constructed a variable coded as "no ADL" if the respondent faced no difficulty in performing any ADLs and "yes" if respondents faced any difficulty in performing any ADL [15, 32, 36]

No

 IADL disability

Yes

IADL consisted of seven difficulties related to instrumental activities such as difficulty in preparing a hot meal (cooking and serving), shopping for groceries, making telephone calls, taking medications, doing work around the house or garden, managing money, such as paying bills and keeping track of expenses and getting around or finding address in an unfamiliar place. IADLs were also recoded as "no IADL" if the respondent faced no difficulty in performing any IADLs and "yes" if respondents having any difficulty in performing any IADL [15, 32, 36]

No

 Self-rated health

Very

Self-rated health was measured on the basis of one question, which was, overall, how is your health in general? which includes five categories for responses, i.e., "Very poor," "Poor," "Fair," "Good," and "Very good" [26, 32, 36, 37]

Poor

Fair

Good

Very good

Pain

Yes

In order to define pain, participants were asked, "Are you often troubled with pain?" then it was coded as "no" and "yes" [15]

No

 Body Mass Index

Underweight

The study focused on assessing the body mass index (BMI), which is a measure of weight in relation to height, among elderly participants. The BMI values were determined using the height and weight measurements of the respondents. The BMI results were then classified according to the World Health Organization's classification system, which categorizes individuals as underweight (BMI < 18.5 kg/m2), normal weight (BMI 18.5–24.9 kg/m2), overweight (BMI 25.0–29.9 kg/m2), and obese (BMI ≥ 30.0 kg/m2) [38,39,40]

Normal

Overweight

Obese

Missing

 Physical activity status

Never

Three distinct classifications of physical activity were established: frequent (daily), infrequent (more than once a week, once a week, or one to three times a month), and never. To evaluate physical activity, individuals were asked the following question: "How frequently do you engage in sports or vigorous activities, such as running, swimming, going to the gym, cycling, or performing physically demanding tasks like digging or lifting heavy objects, chopping wood, or engaging in farm work, fast bicycling, or cycling with heavy loads?" [26, 31]

Frequent

Rare

 Tobacco consumption

Yes

Tobacco usage was assessed through survey questions inquiring about past experiences with smoking tobacco products (e.g., cigarettes, bidis, cigars, hookahs, cheroots) and the use of smokeless tobacco (e.g., chewing tobacco, gutka, pan masala, etc.). Participant responses were coded as either "yes" or "no" [26]

No

 Alcohol consumption

Yes

Similarly, alcohol consumption was evaluated by asking participants if they had ever consumed alcoholic beverages, including beer, wine, liquor, or country liquor. Responses were then coded as either "yes" or "no" [26]

No

 Health insurance coverage

Yes

Health insurance coverage was coded as binary response “yes and “no” [26]

No

Psycho-social factors

 Perceived discrimination

Yes

The perception of discrimination was assessed using six questions, including statements such as, "You receive less courtesy or respect compared to others," "People treat you as if you are not intelligent," "People behave as if they are fearful of you," and "You experience threats or harassment." In addition, respondents' answers were classified into binary categories: "yes" if they reported experiencing discrimination on an almost daily basis, almost every day, a few times a month, or less than once a year, and "no" if they indicated never experiencing discrimination [26]

No

 Marital status

Currently in union

Current research has classified marital status into binary classification, including currently in union and currently not in union [15, 32]. We do not prioritize examining the other non-married categories, despite recognizing that the association between different marital status categories may vary. Consequently, we have simplified the classification of marital status in our study by adopting a binary approach. Those who reported being "currently in union" to indicate their married status, while all other categories such as widowed, never married, separated, divorced, and deserted are consolidated as "currently not in union."

Currently not in union

 Working status

Working

Furthermore, working status was recoded as "Working," "Retired," and "Not working" [31] in this study

Retired

Not working

 Community engagement

Yes

Community engagement was assessed through the process of coding responses to survey questions regarding affiliation with social organizations, religious groups, clubs, or societies. The participants' responses were classified into two categories, namely "yes" and "no" [26]

No

Household factors

 MPCE quintile

Poorest

Using information on household consumption data, the monthly per capita consumption expenditure (MPCE) quintile has been assessed. The sample households were surveyed using sets of 11 and 29 questions on spending on food and non-food items, respectively. Food expenditures were collected during the seven-day reference period, whilst non-food expenditures were collected over 30-day and 365-day reference periods. Using 30-day reference period, expenses for both food and non-food items were standardised. The MPCE is calculated and used as a summary indicator of consumption. The variable was further divided into five quintiles, i.e., from poorest to richest [26]

Poor

Middle

Richer

Richest

 Regions

North

The region was coded as "North," "West," "Northeast," "East," "Central" and "South" [26, 32] in this study

West

Northeast

East

Central

South