Psoriatic Arthritis Hospitalization Is Associated with Increased Health Care Charges: A Report from the National Inpatient Sample

Background: This study aims to compare the outcomes of psoriasis hospitalizations with and without joint involvement. The primary outcome was inpatient mortality, while secondary outcomes were hospital length of stay (LOS) and total hospital charges. Methods: Data were abstracted from the National Inpatient Sample (NIS) 2016 and 2017 databases. The NIS was searched for psoriasis hospitalizations with and without joint involvement as principal or secondary diagnosis using the International Classification of Diseases, tenth revision (ICD-10) codes. Psoriasis hospitalizations for adult patients (aged ≥18 years) from the above groups were identified. Multivariate logistic and linear regression analysis was used to adjust for confounders for the primary and secondary outcomes, respectively. Results: There were over 71 million discharges included in the combined 2016 and 2017 NIS database. A total of 323,405 hospitalizations were for adult patients with either a principal or secondary ICD-10 code for psoriasis. Of these hospitalizations, 77,980 (24.11%) had joint involvement. Psoriasis hospitalizations with joint involvement had similar inpatient mortality (1.42% vs. 1.78%, adjusted odds ratio (AOR): 0.89, 95% CI: 0.76-1.05, p=0.159) compared with those without joint involvement. Psoriasis with joint involvement hospitalizations had a decrease in adjusted mean LOS of 0.15 days (95% CI: 0.26-0.04, p=0.007) compared with the group without joint involvement. Psoriasis with joint involvement hospitalizations had an increase in adjusted mean total hospital charges of $3,655 (95% CI: 2,146-5,164; p<0.0001) compared with the group without joint involvement. Conclusions: Hospitalizations for psoriasis with and without joint involvement have similar inpatient mortality. However, joint involvement increases total hospital charges, which increases the burden to the health care system.