Table 1 Definitions and coding of variables

MSD Treatment compliance

1 = Full compliance; 2 = Most compliance; 3 = Little compliance or not at all

The degree of self-reported MSD treatment compliance

Age

Continuous variable

Gender

1 = male; 2 = female

Marital status

1 = single; 2 = partnered

Poverty

1 = Yes; 2 = No

Whether the respondent was targeted for poverty alleviation

Job

1 = Yes; 2 = No

Whether the interviewee had a job during the survey

Duration

Continuous variable

How many years the respondent had MSD by the time of the survey

Ability of daily life activities (ADL)

Continuous variable

Whether there was difficulty in ten physical activities, 1 = no difficulty, 4 = total difficulty, the variable range is 10–40

HRPTs

1 = None; 2 = ACTs_only; 3 = RFTs_only; 4 = Both

The status of receiving transfer payments from children and relatives

Education

1 = Illiteracy; 2 = Primary school; 3 = Junior middle school and above

Self-rated health (SRH)

1 = Good; 2 = general; 3 = poor; 4 = very poor

Living arrangements

1 = Living alone or living with spouse; 2 = Living with grandchildren

3 = Living with children and grandchildren

Living arrangements with children and grandchildren

Comorbidities

1 = One type; 2 = two types; 3 = three types; 4 = Four types or more

How many types of chronic conditions did the respondent suffer from (including MSD)