Brazil’s public health system is treating only a small fraction of the people estimated to need medication for psoriatic arthritis, and the patients who do get treated are heavily concentrated in the country’s wealthiest states. A nationwide cross-sectional analysis published in Advances in Rheumatology found that just 17 percent of an estimated 126,587 eligible individuals received treatment through the Brazilian Unified Health System, known as the SUS, in 2025. Behind that national average lies a stark territorial divide: the ratio of treated patients to the eligible population varied twenty-fold between federative units, from 0.02 to 0.37.
Psoriatic arthritis is a chronic inflammatory immune-mediated disease associated with significant impairment and reduced quality of life. Although a clinical protocol for its treatment exists within the SUS, the coverage and socioeconomic distribution of pharmacological treatment across Brazil’s states and federal district had remained uncharacterized until this analysis.
The headline finding is a pronounced pro-rich gradient in access. For treatment coverage, the Slope Index of Inequality was 0.167 with a 95 percent confidence interval of 0.053 to 0.280, and the Relative Index of Inequality was 5.304 with a confidence interval of 2.373 to 11.855. In practical terms, federative units at the upper socioeconomic extreme showed roughly four-fold higher coverage than those at the bottom.
Drug consumption followed the same pattern, and even more steeply. Consumption ranged from 2.4 to 78.8 defined daily doses per patient across the country, a thirty-three-fold difference. The inequality indices confirmed this was not random variation: the Slope Index of Inequality for consumption was 48.065 with a confidence interval of 27.381 to 68.749, and the Relative Index of Inequality was 9.404 with a confidence interval of 4.550 to 19.439. States at the top of the socioeconomic distribution consumed approximately nine times more medication per patient than those at the bottom.
Expenditure, by contrast, told a different story. Mean per capita spending ranged from USD 480 to USD 34,184, a seventy-one-fold spread that was the widest relative variation of any measure in the study. Yet when the researchers tested for a socioeconomic gradient, none reached statistical significance. The Relative Index of Inequality for expenditure was 0.986 with a confidence interval spanning 0.404 to 2.406, a range that includes the null value of 1. The authors interpret this combination, high coverage and consumption in richer places without a matching spending gradient, as consistent with a territorial misallocation of resources and an inequitable distribution of health benefits across the system.
The direction of every effect held, with no gradient inversion, meaning the pro-rich patterns in coverage and consumption survived the alternative statistical specification.
The scale of the treatment gap is the study’s most striking number. Of roughly 126,587 people estimated to be eligible for pharmacological treatment nationwide, only 21,731 patient-equivalents actually received it according to the defined daily dose records in the outpatient system. That leaves more than four out of five eligible individuals without recorded treatment, and the shortfall is not evenly shared. A patient living in a federative unit at the bottom of the Human Development Index distribution faces odds of being treated that are a small fraction of those facing a patient in the wealthiest units, and even among those treated, the intensity of medication use, measured in defined daily doses per patient, differs by more than an order of magnitude.
The authors conclude that reducing these inequalities requires strengthening diagnostic and care capacity in lower-HDI states, alongside systematic equity monitoring within the specialized pharmaceutical care component of the SUS.
Subject of Research: Socioeconomic inequalities in the coverage, use and expenditure of psoriatic arthritis pharmacological treatment across Brazil's federative units in 2025
Article Title: Socioeconomic inequalities in psoriatic arthritis treatment in Brazil: a nationwide analysis of coverage, use and expenditure
Article References: Mosegui, G. B. G., Antoñanzas-Villar, F., de Mello Vianna, C. M., Lucietto, D. A., & Gil-López, A. J. (2026). Socioeconomic inequalities in psoriatic arthritis treatment in Brazil: a nationwide analysis of coverage, use and expenditure. Advances in Rheumatology. https://doi.org/10.1186/s42358-026-00575-7
Image Credits: AI Generated
DOI: 10.1186/s42358-026-00575-7
Keywords: psoriatic arthritis, Brazil, Unified Health System, SUS, health inequality, Slope Index of Inequality, Relative Index of Inequality, Human Development Index, pharmaceutical care, defined daily doses, treatment coverage, health expenditure
News Source: Phoebe Ingram. (October 30, 2026). Richer Brazilian States Get Far More Psoriatic Arthritis Treatment, Nationwide Study Finds. Scienmag.
