Table 1 Operational definitions of the study variables

 Abdominal obesity

- Without abdominal obesity: waist circumference < 90 cm for men or < 80 cm for women;

- With abdominal obesity: waist circumference ≥ 90 cm for men or ≥ 80 cm for women [34, 57].

 Age group

50–59, 60–69, 70–79, 80+ years.

 Education

- No formal education: never having any formal education;

- ≤ 6 years: not completed elementary school, completed elementary school;

- > 6 years: completed junior high school, high school, academy or university, master degree.

 Occupation

- Non-physical labour: government worker, non-government worker, self-employed;

- No occupation: retired, housewife, not-having a job;

- Physical labour: farmer, fishermen, driver, rickshaw driver.

 Marital status

- Single/widowed: not married, divorced, separated, widowed;

- Partnership: married, living together.

 Residence

Coastal, inland, hilly & mountainous

 Wealth index

Composite index created using PCA and grouped into quintiles: 1^st (poorest), 2^nd (poor), 3^rd (middle), 4^th (rich), 5 ^th (richest).

 Smoking

- Non-current smokers: never smokers, ex-smokers

- Current smokers: currently smoked daily or non-daily.

 Self-reported chronic disease

- No: did not report having any chronic disease;

- Yes: reported having at least one (≥ 1) of the chronic conditions including: hypertension, diabetes, stroke, cardiovascular disease (CVD), chronic obstructive pulmonary disease (COPD), asthma, and cancer.