Table 1 Variables description

Unmet healthcare needs

During the past 12 months, was there a time when you did not receive the medical service you needed? ‘yes’ or ‘no’

Reasons for unmet healthcare needs

If the response about unmet healthcare needs is ‘yes’, why? (1) economic hardship, (2) inaccessible transportation, (3) physical disabilities, (4) problems finding childcare, (5) mild symptoms, (6) lack of information about hospitals, (7) lack of available time, (8) difficulties in getting appointments at hospitals, (9) no regular family doctor, and (10) other.

According to previous research [21], the reasons for unmet healthcare needs were classified into three categories: ‘economic hardship’ (economic hardship), ‘scheduling conflict’ (lack of available time) and ‘other reasons’ (inaccessible transportation, physical disabilities, problems finding childcare, mild symptoms, lack of information about hospitals, difficulties in getting appointments at hospitals, no regular family doctor, and other).

Household income

Household income calculated and equalized by taking the square root of the number of household members. Household income was divided into five quintiles, the 1st quintile is the lowest quintile (lowest 20%), and the 5th quintile is the highest (highest 20%) quintile.

In this study, household income was classified into three categories: ‘1st quintile’, ‘2nd quintile’, and ‘3rd quintile or more’.

Current smoker

Do you currently smoke?

Responses were rated on a 4-point scale: (1) currently smoking every day, (2) sometimes smoking, (3) former, and (4) never.

In this study, current smoker was classified into two categories: ‘yes’ (currently smoking every day and sometimes smoking) and ‘no’ (former and never).

Usual source of care

When you are sick or need advice from a doctor for your health, are there any medical institutions that you usually visit? ‘yes’ or ‘no’

Regular family doctor

When you are sick or need advice about your health, do you have a doctor who visits often? ‘yes’ or ‘no’

Disability

Have you ever been diagnosed with a disability from a doctor? ‘yes’ or ‘no’

Depressive symptoms

Did you have difficulty in daily life due to feeling sad or unhappy for more than two weeks in the past year? ‘yes’ or ‘no’

Visual impairment

Do you have a vision difficulty?

Responses were rated on a 4-point scale: 1 (never) to 4 (always).

In this study, visual impairment was classified two categories: ‘yes’ (2–4) and ‘no’ (1).

Hearing impairment

Do you have a hearing difficulty?

Responses were rated on a 4-point scale: 1 (never) to 4 (always).

In this study, visual impairment was classified two categories: ‘yes’ (2–4) and ‘no’ (1).

Memory impairment

Do you have difficulty in daily life due to mental confusion or memory loss? ‘yes’ or ‘no’

Decision-making impairment

Are you having difficulty making decisions that hinder your daily life? ‘yes’ or ‘no’