33760 Mortality in patients with pemphigus: a retrospective US claims database study

Objective: We evaluated mortality in patients with pemphigus compared with non-pemphigus individuals matched on age and gender, in the United States (US). Methods: This retrospective cohort study used data from the US Optum Clinformatics claims database between May 1, 2000 and December 31, 2020. Mortality was assessed during a follow-up of up to 4 years after the index date (first pemphigus diagnosis). A sensitivity analysis was conducted (end of study period, March 31, 2020) to exclude the potential impact of COVID-19 on mortality analysis. Multivariable models (comorbidities as adjustment variables) were used to assess hazard ratios (HRs). Propensity score matched (PSM) model was used to minimize comorbidities difference at baseline. Results: Overall, 1391 patients with pemphigus (ICD-9 and ICD-10 codes) were identified (mean [SD] age: 63.7 [17.9] years; females: 57.0%). During follow-up, 227 patients (16.3%) died in the pemphigus cohort, compared with 172 patients (12.4%) in the non-pemphigus cohort. Pemphigus patients had higher death rate than the non-pemphigus cohort (adjusted HR [95% CI]: 1.69 [1.37–2.09]; unadjusted HR [95% CI]: 1.33 [1.09–1.63]; PSM HR [95% CI]: 1.49 [1.19–1.86]; P < .01 for all). Similar results were observed in the sensitivity analysis (adjusted HR [95% CI]: 1.77 [1.41–2.23]; P < .01); PSM HR [95% CI]: 1.52 [1.20–1.93]; P < .01]). Infections, hypertension, diabetes, hematologic abnormalities, and cardiovascular comorbidities were strongly associated with mortality in pemphigus patients. Conclusions: These results suggest that pemphigus is associated with increased mortality observed over 4 years, highlighting the need for better treatment options for these patients.