Epidemiology of Sarcoidosis 1946-2013: A Population-Based Study.

OBJECTIVE: To characterize the epidemiology of sarcoidosis from 1946 through 2013.

PATIENTS AND METHODS: An inception cohort of patients with incident sarcoidosis from January 1, 1976, through December 31, 2013, in Olmsted County, Minnesota, was identified based on comprehensive individual medical record review. Inclusion required physician diagnosis supported by histopathologic confirmation, radiologic features of intrathoracic sarcoidosis, and a compatible clinical presentation. Data were collected on demographic characteristics, clinical presentation, laboratory investigations, and mortality. The data were augmented with a previously identified cohort of Olmsted County residents diagnosed as having sarcoidosis in 1946-1975. Incidence rates were age and sex adjusted to the 2010 US white population.

RESULTS: A total of 448 incident cases of sarcoidosis were identified (mean age, 44.2 years; 52% women). The annual incidence of sarcoidosis was 10.0 per 100,000 population. The incidence of sarcoidosis increased in women from 1950 to 1960, but otherwise there were no significant calendar year trends. However, the peak age at incidence for women shifted from 40 to 59 years in 1950 to 50 to 69 years in 2010. Similarly, the peak age at incidence for men shifted from 30 to 49 years in 1950 to 40 to 59 years in 2010. Ninety-seven percent of patients had intrathoracic involvement, but only 43% had respiratory symptoms. The overall mortality of patients with sarcoidosis was not different from that of the general population (standardized mortality ratio=0.90; 95% CI, 0.74-1.08).

CONCLUSION: Sarcoidosis occurred in approximately 10 persons per 100,000 per year. Most of the patients had intrathoracic involvement, although less than half had respiratory symptoms. Overall mortality was not different from that of the general population.