Does the inverse theory hypothesis apply to primary health care? Evidence from 5 564 Brazilian municipalities

Abstract

Objective. To investigate the evolution of primary health care (PHC) coverage in Brazilian municipalities from 2007 to 2016 from the perspective of the inverse theory hypothesis. Method. This ecological study was performed with data from 5 564 Brazilian municipalities. Data were obtained from the Brazilian Institute of Geography and Statistics (IBGE) and from the Unified Health System database (DATASUS). The municipalities were classified according to their social development status using selected cluster indicators. After classification of the municipalities, PHC was analyzed by determining Family health Strategy (FHS) coverage through means and interquartile distance, with analysis of time series and correlations between variables. Results. Two groups of municipalities were detected: a group with more favorable (n = 3 293) and a group with less favorable conditions (n = 2 271). The difference between the groups for all indicators was statistically significant (P < 0.001). In general, regardless of the group, an increase in FHS coverage was detected along the study period. However, from 2009 on, mean FHS coverage became higher in the group with less favorable conditions. The increase in coverage was also faster in this group. Finally, a change in the correlation between indicators and PHC coverage in the first vs. last year of the historical series indicates that the criteria used to expand coverage in the group with less favorable conditions shifted to favor absolute poverty rather than inequality. Conclusions. PHC in Brazil fulfills its role of reducing access inequalities. Therefore, the inverse theory hypothesis does not apply to this case.