Longitudinal Trends of Hospitalizations for Giant Cell Arteritis: A 21-Year Longitudinal National Population-Based Study.

Background Long-term longitudinal studies on giant cell arteritis (GCA) hospitalizations are limited. Here we aim to fill gaps in knowledge by analyzing longitudinal trends of GCA hospitalizations over the last two decades in the United States (U.S.). Materials and methods We performed a 21-year longitudinal trend analysis of GCA hospitalizations using data obtained from the National Inpatient Sample (NIS) database between 1998 and 2018. Using the NIS database, we searched for hospitalizations for patients aged ≥ 50 years with a principal diagnosis of GCA using ICD billing codes. The principal diagnosis was the main reason for hospitalization. We used all hospitalizations in patients without GCA aged ≥50 years as the control population. Multivariable logistic and linear regression analysis was utilized to calculate the adjusted p-trend for outcomes of interest. Results The incidence of GCA hospitalization remained stable at about one per 100,000 U.S. persons throughout the study period. There was no statistically significant change in the inpatient mortality for the GCA group during the study period (adjusted p-trend=0.111). In comparison, inpatient mortality reduced from 4.4% to 3.1% from 1998 to 2018 (adjusted p-trend <0.0001) in the control group. The proportion of whites reduced, while the proportion of racial minorities increased over time in both the GCA and control groups. Conclusion The non-GCA control population saw significant reductions in mortality over time, but unfortunately, the GCA group did not see such improvements. More research into additional treatment modalities for inpatient GCA management may help improve mortality.