Incidence of referred progressive collapsing foot deformity in the Swedish general population

Abstract

Abstract Background: Progressive collapsing foot deformity (PCFD) is a disabling condition that may require complex surgical treatment. Little is known about the incidence of PCFD in the general population and specifically of PCFD requiring specialist care. Methods: We conducted a nation-wide epidemiological study to estimate the incidence of referred PCFD in the general population. We retrieved data from the Swedish National Patient Register. All individuals aged 16 years or older, with a first-time diagnosis of PCFD (ICD-10 code M214) between 2007 and 2018 were identified. Total incidences, change over time, gender- and age specific incidences per 100,000 person-years were calculated using population size data from Statistics Sweden. Incidences were compared using Poisson test. Results: The incidence rate (IR) of referred PCFD in the general population was 23.0 (95% CI 22.7-23.3) per 100,000 person-years. The IR in women was 30.4 (95% CI 29.9-30.8) and in men 15.4 (95% CI 15.1-15.8). The highest IRs were found in the age group 61-75 years old. Among the 21 regions in Sweden, large variations in the IRs were found, with age- and sex-standardized IRs ranging from 8.3 (95% CI 7.2-9.4) to 69.1 (95% CI 62.4-75.8). Conclusion: PCFD requiring specialist care is common in the general population. The incidence in women is almost double that in men. Large unexplained regional variations in the incidence rates exist.