Frequency of health-care service use and severity of illness in undocumented migrants in Catalonia, Spain: a population-based, cross-sectional study.

Background: In Spain, legislation was passed in 2012 excluding undocumented migrants from the public health-care system. Catalonia was one of the Spanish regions that did not implement this legislation, and continued to guarantee access to health care to the whole population. We aimed to analyse health-care use and health status among undocumented migrants in Catalonia, and compare health-care use and health status with legal residents classified according to their socioeconomic position (SEP).

Methods: We did a population-based, cross-sectional study, with administrative individual data. The study included the resident population in Catalonia, Spain, in 2017, aged younger than 65 years and with a maximum annual income of less than €18 000 per year, and classified into three socioeconomic (SEP) groups-low SEP, very low SEP, and undocumented migrants. Indicators regarding health-care service use (primary care, emergency care, mental health care, acute care), drug prescriptions, and selected chronic and infectious diseases were analysed.

Findings: Between Jan 1 and Dec 31, 2017, 4 071 988 residents of Catalonia were included in this study; undocumented migrants represented 2·8% (n=113 450) of this population. Of all undocumented migrants, 25 942 (61·0%) female participants aged 15-64 years and 19 819 (46·0%) male participants aged 15-64 years attended primary health-care centres: these rates were lower than in individuals with a very low SEP (84·8% in female participants and 72·1% in male participants). Hospital admission rates among male participants aged 15-64 years in the very low SEP group were more than three times as high as in undocumented migrants (111·6 vs 35·7). The highest tuberculosis rate was found in undocumented male migrants (incidence rate 4·35 [95% CI 3·55-5·16]).

Interpretation: Undocumented migrants made less use of health-care services than those in the low and very low SEP groups, but for some infectious diseases, incidence was higher in undocumented migrants. These results constitute an additional argument to support the maintenance of universal health coverage for all citizens.

Funding: None.