Fig. 1

Unexplained differences in GP visits between the quintile with lowest GP usage and higher-usage quintiles. Notes: The unexplained differences in GP visits per capita were expressed as coefficients of quintile dummy variables. The division into five quintiles was based on unadjusted GP visits per capita. The three models were a series of linear multiple linear regression models that used GP visits per capita as the dependent variable and differed in the sets of covariates added as independent controls. The first model contained only dummy variables for the quintiles, representing the differences in GP usage across the quintiles. The second model added the variables from demand-side, such as age, gender, and health-related indicators. The third model contained supply-side factors as well as demand-side variables: the density of GP and specialists and the number of EDs. All the estimated coefficients were statistically significant