Variation in primary health care services after implementation of quality improvement policy in Brazil.

Background: Brazil is the most populous country with a public, universal and free health care system. The National Program for Access and Quality Improvement in Primary Care (PMAQ) was created to improve the quality of primary health care (PHC).

Objective: To evaluated whether progress generally has been made within Brazil's PHC since PMAQ implementation, and if changes occurred uniformly in the country, while also identifying municipal characteristics that may have influenced the improvement.