Oral primary care: an analysis of its impact on the incidence and mortality rates of oral cancer.

BACKGROUND: Oral cancer is a potentially fatal disease, especially when diagnosed in advanced stages. In Brazil, the primary health care (PHC) system is responsible for promoting oral health in order to prevent oral diseases. However, there is insufficient evidence to assess whether actions of the PHC system have some effect on the morbidity and mortality from oral cancer. The purpose of this study was to analyze the effect of PHC structure and work processes on the incidence and mortality rates of oral cancer after adjusting for contextual variables. METHODS: An ecological, longitudinal and analytical study was carried out. Data were obtained from different secondary data sources, including three surveys that were nationally representative of Brazilian PHC and carried out over the course of 10 years (2002-2012). Data were aggregated at the state level at different times. Oral cancer incidence and mortality rates, standardized by age and gender, served as the dependent variables. Covariables (sociodemographic, structure of basic health units, and work process in oral health) were entered in the regression models using a hierarchical approach based on a theoretical model. Analysis of mixed effects with random intercept model was also conducted (alpha = 5%). RESULTS: The oral cancer incidence rate was positively association with the proportion of of adults over 60 years (ß = 0.59; p = 0.010) and adult smokers (ß = 0.29; p = 0.010). The oral cancer related mortality rate was positively associated with the proportion of of adults over 60 years (ß = 0.24; p < 0.001) and the performance of preventative and diagnostic actions for oral cancer (ß = 0.02; p = 0.002). Mortality was inversely associated with the coverage of primary care teams (ß = -0.01; p < 0.006) and PHC financing (ß = -0.52-9; p = 0.014). CONCLUSIONS: In Brazil, the PHC structure and work processes have been shown to help reduce the mortality rate of oral cancer, but not the incidence rate of the disease. We recommend expanding investments in PHC in order to prevent oral cancer related deaths.