While younger age and diabetes were still associated with significant increases in infection-related hospitalization expenditures in this model, the presence of a lung infection during the hospitalization was not a significant predictor (Table 4).
Several possible arguments may help explain the positive association between daily tobacco use and food expenditures in the adjusted model.
Furthermore, we tested for endogeneity of the expenditure variable in the model.
Furthermore, we corrected for endogeneity of the expenditure variable in the model by using the augmented regression technique.
Paralleling prior research, age, sex, and race/ethnicity contributed significantly to healthcare expenditures in the GLM models, reported in full (Additional file 2, Table S2).
For example, an individual with a serious car accident will have very high medical expenditures in year 1, and will be predicted to be a high-expenditure user in year 2 if prior expenditures are included in the model.
Therefore, this study adopts these three variables to operationalize healthcare utilization as "frequency of doctor visits in the past year," "days of hospitalization in the past year," and "total healthcare expenditures in the past year," averaging 2838 yuan (logarithm of healthcare expenditures was included in the model).
These variables were: a) households with expenditure for treating chronic illness and b) households that faced hospital expenditure (both included in the model as dichotomous variable); c) quintile groups and d) geographical location of the household included in the model as categorical variables.
To explore the relationship between WTK and health-related quality of life in more detail, two subsequent analyses were conducted separately for all exercisers, in which calorie expenditure was considered in the model, and for the study group, in which practicing year was added to examine the cumulative effect of WTK.
On the other hand, despite literature reports that institutional care has a pivotal role in long-term care expenditures, we demonstrated that institutional care interacting with higher care needs level is a relevant factor in explaining the highest LTC expenditures in our model.
