Trends in Hospitalization Rates, Major Causes of Hospitalization, and In-Hospital Mortality in Rheumatoid Arthritis in the United States From 2000 to 2014.

objectiveTo evaluate national trends in hospitalizations and in-hospital mortality in rheumatoid arthritis (RA).

methodsNational Inpatient Sample from 2000-2014 and United States Census data were used to study temporal trends in adult RA hospitalizations, reasons for hospitalizations, and in-hospital mortality.

resultsThe data represented 183 983 hospitalizations with a primary diagnosis of RA. The annual rates of hospitalization for the primary diagnosis of RA decreased from 76.54 admissions per 1 million in 2000 to 29.96 per 1 million in 2014 (P trend < 0.0001). The hospital mortality rate declined from 0.70% to 0.41% (P trend < 0.0001) in this group. With a primary or nonprimary diagnosis of RA, the mortality rate ranged between 1.95 and 2.87 (P trend 0.08). For a nonprimary diagnosis of RA, we noted that the proportion of hospitalizations with a diagnosis of myocardial infarction (6.4% in 2000 to 4.6% in 2014; P < 0.001) significantly decreased, but the absolute number of hospitalizations significantly increased. In contrast, the proportion and the absolute number of hospitalizations with any diagnosis of sepsis, congestive heart failure, lung disease, and urinary tract infection increased significantly. We also noted a significant increase in the actual rate and proportions for hospitalizations for hip and knee arthroplasty. Among in-hospital deaths when RA was a nonprimary diagnosis, the most common primary diagnosis was pneumonia (12.5 %) in 2000, whereas sepsis accounted for the most deaths in 2014 (31.4%).

conclusionWe observed that hospitalization rates and in-hospital mortality rates in patients with RA have changed significantly over the past 15 years.