Serious infections in people with polymyalgia rheumatica (PMR) or giant cell arteritis (GCA): a time-trend national US study

To assess incidence, time-trends, and outcomes of serious infections in people with polymyalgia rheumatica (PMR) or giant cell arteritis (GCA).

We examined the 1998–2016 US National Inpatient Sample for serious infections in PMR or GCA, namely, opportunistic infections (OI), skin and soft tissue infections (SSTI), urinary tract infection (UTI), pneumonia, and sepsis/bacteremia. Multivariable-adjusted logistic regressions assessed association of the type of infection, demographics, comorbidity, and hospital characteristics with healthcare utilization and mortality.

Hospitalized with serious infections, those with PMR or GCA were 2 decades older than people without PMR or GCA, and more likely to be female or white or have higher Deyo-Charlson index score or higher income. Sepsis rates in the general population, PMR, and GCA cohorts were 10.2%, 17.7%, and 18.9% in 2015–2016, respectively. Incidence rates of serious infections/100,000 NIS claims in PMR and GCA in 2015–2016 were as follows (rounded off): OI, < 1 and < 1; SSTI, 4 and 1; UTI, 4 and 1; pneumonia, 9 and 2; and sepsis, 20 and 4, respectively. Sepsis surpassed pneumonia as the most common serious infection in 2011–2012. In multivariable-adjusted analyses in the PMR cohort, sepsis, female sex, Deyo-Charlson comorbidity score ≥ 2, Medicare or Medicaid insurance, urban hospital location, and large hospital bed size were associated with significantly higher healthcare utilization and/or in-hospital mortality. Similar associations were noted in the GCA cohort.

Incidence of serious infections, especially sepsis, increased in both PMR and GCA cohorts over time. Interventions to improve serious infection outcomes in PMR/GCA are needed.