The relationship between private health plans and use of medical and dental health services in the Brazilian health system.

To describe the last place of medical and dental health service used in relation to private health plans, and examine the effect of being registered in the primary healthcare system through the Family Health Strategy (FHS). This was a cross-sectional study using data from Brazil's 2008 National Household Survey. Multinomial logistic regression was performed to analyze how a private health plan and enrollment in the FHS influenced the use of health services. Results showed that individuals with a private health plan tend to use medical and dental services more than individuals without such a plan. However, many individuals with a private health plan used public services or paid out-of-pocket services, mainly for dental care. Among individuals without a private plan, being enrolled in the FHS reduced the use of out-of-pocket private services, regardless of age, income or educational level. Enrollment in the FHS increased the chances of using public services, and the effect of this enrollment is greater among those who have a private plan. Policies to strengthen public primary healthcare and to expand the FHS should be encouraged within the universal health system.