Epidemiology of Polymyalgia Rheumatica 2000-2014 and Examination of Incidence and Survival Trends Over 45 Years: A Population-Based Study.

OBJECTIVE

To determine time trends in the incidence and survival of polymyalgia rheumatica (PMR) over a 15-year period in Olmsted County, Minnesota, and to examine trends in incidence of PMR in the population by comparing this time period to a previous incidence cohort from the same population base.

METHODS

All cases of incident PMR among Olmsted County, Minnesota residents in 2000-2014 were identified to extend the previous 1970-1999 cohort. Detailed review of all individual medical records was performed. Incidence rates were age- and sex-adjusted to the US white 2010 population. Survival rates were compared with the expected rates in the population of Minnesota.

RESULTS

There were 377 incident cases of PMR during the 15-year study period. Of these, 64% were female and the mean age at incidence was 74.1 years. The overall age- and sex-adjusted annual incidence of PMR was 63.9 (95% confidence interval [95% CI] 57.4-70.4) per 100,000 population ages ≥50 years. Incidence rates increased with age in both sexes, but incidence fell after age 80 years. There was a slight increase in incidence of PMR in the recent time period compared to 1970-1999 (P = 0.063). Mortality among individuals with PMR was not significantly worse than that expected in the general population (standardized mortality ratio 0.70 [95% CI 0.57-0.85]).

CONCLUSION

The incidence of PMR has increased slightly in the past 15 years compared to previous decades. Survivorship in patients with PMR is not worse than in the general population.