Dependent and independent variables
| Categories | Indicators/survey questions | |
| Dependent variables | ||
| Non-use of outpatient services | Reported non-use of outpatient/no reported non-use of outpatient services | Questions: Have you been ill in the last month? What was the main reason for not seeking outpatient treatment? |
| Non-use of inpatient services | Reported non-use of inpatient/no reported non-use of inpatient services | Question: In the past year, did a doctor suggest that you needed inpatient care but you were not get hospitalised? |
| Non-use of physical examinations | Not undergoing physical examination/undergoing physical examination | Question: Did you have a physical examination in the last 2 years? |
| Independent variables | ||
| Predisposing factors | ||
| Sex | Male/female | |
| Age (years) | ≤55/56–65/66–75/≥75 | |
| Marital status | Not married/married | Question: What is your marital status? |
| Employment/retirement status | Employed/not employed/retired | Employed: respondents reported that they had engaged in any type of employment; not employed: not working in the last year or retired without pension; retired: retired with pension. |
| Education | Less than lower secondary/upper secondary and vocational training/tertiary | Question: What is your highest level of education? |
| Household numbers | ≤2 persons in household/≥3 persons in household | Number of household members |
| Enabling factors | ||
| Social health insurance | 0, no social health insurance/1, UEMI/2, URMI/3, NCMI | Question: Are you the policy holder/primary beneficiary of any type of health insurance? |
| Income level | ≤¥1495/¥1496–8126/¥8127–20 533/≥¥20 533 | Yearly household income divided by the number of household members; first household member with a weight of 1, all following household members with a weight of 0.5. |
| Transfer received | Financial transfers received from others/no financial transfers received from others | The total amount of financial transfers that the respondent and spouse received in the past year. |
| Transfer given | Financial transfers given to others/no financial transfers given to others | The total amount of financial transfers that the respondent and spouse gave in the past year. |
| Area of residence | Urban/rural | |
| Need factors | ||
| Self-reported health | Excellent/very good/good/fair/poor | Question: Would you say your health is excellent, very good, good, fair or poor? |
| Chronic | No chronic/one chronic/multiple chronic diseases | Question: Have you been diagnosed with any chronic diseases (conditions listed below; respond to each one) by a doctor? |
| Depression (Center for Epidemiological Survey (CESD) scores) | No depression (CESD<10)/probability of being depression (10≤CESD < 20)/depression (CESD≥20) | Ten questions of the CESD (Depression Scale) |
| BMI | ≤18.5/18.624/≥24.1 | BMI is the weight divided by the square of the height. |
| ADL | Without ADL/with any ADL | The ADLs proposed by Wallace and Herzog30 in their paper, including bathing, dressing and eating. Getting in/out of bed was added in CHARLS. |
| Drinking | No/yes | Whether the respondent drank alcoholic beverages in the past |
| Smoking | No/yes | Whether the respondent reports ever having smoked or presently smoking |
ADL, activities of daily living; BMI, body mass index; CHARLS, China Health and Retirement Longitudinal Study; NCMI, new cooperative medical insurance; UEMI, urban employee medical insurance; URMI, urban resident medical insurance.