The risk of post-polio syndrome among immigrant groups in Sweden.

To examine the risk of post-polio syndrome (PPS) in immigrant groups using native Swedish-born individuals as referents. This is a retrospective study. The study population included all individuals aged 18 years and older registered in Sweden. PPS was defined as having at least one registered diagnosis in the Swedish National Patient Register. The incidence of post-polio in different immigrant groups, using Swedish-born individuals as referents, was assessed by Cox regression, with hazard ratios (HRs) and 99% confidence intervals (CI). The models were stratified by sex and adjusted for age, geographical residence in Sweden, educational level, marital status, co-morbidities, and neighbourhood socioeconomic status. In total 5300 post-polio cases were registered, 2413 males and 2887 females. Fully adjusted HRs (99% CI) in immigrants versus Swedish-born were 1.77 in men (1.52-2.07) and 1.39 (1.19-1.62) in women. Statistically significant excess risks of post-polio were found in the following subgroups: men and women from Africa, HRs (with 99% CI) 7.40 (5.17-10.59) and 8.39 (5.44-12.95), respectively, and Asia, HRs 6.32 (5.11-7.81) and 4.36 (3.38-5.62) respectively, and in men from Latin America, HR 3.66 (2.17-6.18). It is of importance to be aware of risks of PPS in immigrants settled in Western countries, and that it is more common in immigrants from regions of the world where polio is still prevalent. Patients with PPS need treatment and proper follow-up until polio has been eradicated through global vaccination programs.