Regional disparities in access to spirometry in the Brazilian public health system

Objective: To describe the spatial distribution of spirometry tests recorded in the Brazilian Sistema Único de Saúde (SUS, Unified Health Care System) in 2023 and 2024. Methods: This was a population-based observational study analyzing all spirometry records in the SUS Outpatient Database for the 2023-2024 period across all 5,570 Brazilian municipalities. Rates of spirometry per 100,000 population were calculated by using population projections from the Brazilian Institute of Geography and Statistics, considering only individuals ≥ five years of age, and subtracting those with private health insurance-as per data from the National Regulatory Agency for Private Health Insurance and Plans. Results: A total of 718,464 spirometry tests were recorded in the SUS during the study period (341,654 in 2023 and 376,810 in 2024). The tests were performed in only 398 municipalities (7.1% of the total number of Brazilian municipalities). It is estimated that approximately 83.5 million individuals, representing 61% of the SUS-dependent population, live in municipalities without any records of spirometry. The median distance to the nearest municipality with spirometry was 50 km, being as high as 902 km in remote areas of the Amazon region. The southeastern region had the highest proportion of municipalities providing the test (11.6%), and the northern region had the lowest (2.7%). Among the state capitals, there was marked heterogeneity in test rates, with Vitória at the top (with 2,406 tests per 100,000 population) and Macapá recording no tests. Conclusions: Access to spirometry in the SUS is highly unequal, with severe geographic and population-based disparities. A significant proportion of the population lacks local availability, often requiring long travel distances to have access to spirometry.