OBJECTIVES: To document the epidemiology, economic burden and all-cause mortality among palmoplantar pustulosis (PPP) patients seen in Canadian hospitals, emergency departments (ED) and hospital-/community-based outpatient clinics, and to compare with plaque psoriasis (PP).

METHODS: Data from the Canadian Institute for Health Information were used to identify adult Canadians (excluding Quebec) hospitalized or visiting an ED or hospital-/community-based outpatient clinic between April 1, 2010 and March 31, 2020 with a diagnosis code of PPP (i.e., ICD-10-CA L40.3) or PP (ICD10-CA L40.9 or L40.0). Patient characteristics and 10-year costs associated with hospitalizations and visits to an ED or hospital-/community-based outpatient clinic for which the most responsible diagnosis (MRD) was PPP or PP (i.e., “MRD costs”) were documented as well as inpatient all-cause mortality when adjusting for patient characteristics. Multivariable generalized linear models (gamma distribution; log link) and logistic regressions were respectively used for comparing costs and all-cause inpatient mortality between PPP and PP. Sensitivity analyses were conducted considering costs associated with any inpatient resource use independently of the presence of a PPP/PP code (i.e., “all-cause costs”).

RESULTS: Over the 10-year period, 338 PPP (10-year prevalence rate: 1.54/1,000,000) and 24,828 PP (10-year prevalence rate: 113.13/1,000,000) unique individuals were identified with a PPP and PP code, respectively. Compared with PP patients, PPP patients were younger (mean age [standard deviation] of 50.9 [17.7] years versus 53.3 [18.3] years; p=0.01) and mostly female (59% versus 44%; p<0.01). Compared with PP patients, PPP patients incurred higher 10-year MRD mean (SD) costs (i.e., $544 [$1,874] versus $132 [$833]; p <0.01) and lower inpatient all-cause mortality (3.9% versus 7.3%; p=0.12). Ten-year all-cause mean (SD) costs were $33,348 ($71,610) for PPP and $42,574 ($83,960) for PP (p<0.01).

CONCLUSIONS: Findings indicated that PPP patients incurred significantly higher costs than PP when healthcare resource utilization were due to MRD of PPP or PP.