Incidence, mortality, and national costs of hospital admissions for potentially preventable infections in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) patients have high infection rates. Streptococcus pneumoniae, herpes zoster (HZV), and influenza are common and potentially preventable causes of morbidity and mortality. Vaccinations have been shown to reduce the rates of these infections. In this study, we aim to determine incidence, mortality, and national costs of hospital admissions for Streptococcus pneumoniae, HZV, and influenza infections in patients with RA. We conducted a retrospective analysis of the adult RA hospitalizations in 2016 from the National Inpatient Sample database. We limited the RA cases to hospitalizations with a principal discharge diagnosis of S. pneumoniae, HZV, and influenza infections. The total number of discharges, age, length of stay, mortality, and hospital charges were recorded. In 2016, 552,230 adult hospitalizations had either a primary or secondary diagnosis of RA. Among this group, there were 1120 hospitalizations for influenza, 590 hospitalizations for herpes zoster, and 785 hospitalizations for S. pneumoniae. These infections constituted 0.5% of RA hospitalizations and were a more common cause of hospitalizations when compared to non-RA hospitalizations. Aggregate annual national hospital charges reached $124 million and an aggregate annual LOS of 13,750 days. Infections, such as influenza, HZV, and S. pneumoniae, remain a common cause of inpatient morbidity and mortality among RA patients. Additionally, the economic burden of these infections is significant. Universal vaccination programs in RA patients, as well as other interventions aiming to improve quality of care of this susceptible population, should be further studied to reduce hospitalizations, cost, morbidity, and mortality.