Table 2 Description of core explanatory variable and control variables

Core explanatory variable (X)

Annual outpatient reimbursement ratio

It is a percentage which is equal to the annual expenditure of the basic medical insurance funds on outpatient services for a diabetes patient divided by his or her annual outpatient expenses

Control variable

(U_i)

Age

——

Nervous system disease

Whether a diabetes patient utilized any medical services because of nervous system disease within one year (Yes = 1, No = 0)

Musculoskeletal system and connective tissue disease

Whether a diabetes patient utilized any medical services because of musculoskeletal system or connective tissue disease within one year (Yes = 1, No = 0)

Circulatory system disease

Whether a diabetes patient utilized any medical services because of circulatory system disease within one year (Yes = 1, No = 0)

Benign tumor

Whether a diabetes patient utilized any medical services because of benign tumor within one year (Yes = 1, No = 0)

Malignant tumor

Whether a diabetes patient utilized any medical services because of malignant tumor within one year (Yes = 1, No = 0)

Digestive system disease

Whether a diabetes patient utilized any medical services because of digestive system disease within one year (Yes = 1, No = 0)

Eye and adnexal disease

Whether a diabetes patient utilized any medical services because of eye or adnexal disease within one year (Yes = 1, No = 0)

Endocrine, nutritional and metabolic disease

Whether a diabetes patient utilized any medical services because of endocrine, nutritional or metabolic disease within one year (Yes = 1, No = 0)