A population-based prevalence of adults with dermatomyositis and polymyositis in Colombia: a bayesian approach

Idiopathic inflammatory myopathies are a heterogeneous group of chronic autoimmune diseases characterized by inflammation and muscle weakness. In Colombia, these conditions have been poorly studied. Therefore, an analysis of the prevalence and demographic characteristics of the main reported inflammatory myopathies in the country (dermatomyositis and polymyositis) was carried out, based on data from the Ministry of Health.

A descriptive observational study was conducted. Bayesian methods were employed for frequency analysis. Data were collected from the Comprehensive Information System of the Ministry of Health of Colombia during the period 2018 to 2021. Key diagnostic codes from the international manual of diseases (ICD-10) related to dermatomyositis and polymyositis were used.

A prevalence of 8.3 cases per 100,000 inhabitants was found, with a female-to-male ratio of 2.4:1 and an average age of 51.5 years. These conditions were more common in the age group between 71 and 80 years. The highest prevalence was observed in the western area of Colombia, especially in Antioquia and in the Eje Cafetero region.

The point prevalence during the period from 2018 to 2021 remained relative constant. A predominance of these diseases was found in the female population of advanced age, with the Southwest region being the most affected and the Southeast being the least affected. This study is one of the few focused on describing the epidemiology of dermatomyositis and polymyositis in Colombia recently and is the first one made using a Bayesian statistical approach in this specific topic and population.