Clinical characteristics and health‐care resource utilization in patients with generalized pustular psoriasis using real‐world evidence from the Japanese Medical Data Center database

Little is known about the disease burden, health-care resource utilization (HCRU), or treatment of patients with generalized pustular psoriasis (GPP) in Japan. This retrospective cohort study used data from the Japanese Medical Data Center database to compare the demographics, comorbidities, and medication use of patients with GPP and plaque psoriasis and estimate their all-cause HCRU. The patient selection period was from January 1, 2015 to December 31, 2019, and patients must have had at least one confirmed inpatient claim or outpatient claim for GPP or plaque psoriasis. During the 12-month follow-up period, 110 patients with GPP and 20,254 patients with plaque psoriasis were identified. An age- and sex-matched (4:1) comparator control cohort, including members of the general population without a diagnosis of psoriasis (but allowing for a diagnosis of psoriatic arthritis), GPP, or palmoplantar pustulosis, was used. The most prevalent comorbidities in patients with GPP included allergic rhinoconjunctivitis, hypertension, and peptic ulcer disease. Patients with GPP were more likely to experience more comorbidities than those with plaque psoriasis, including asthma, chronic obstructive pulmonary disease, interstitial pneumonia, hyperuricemia and gout, tonsillitis, psoriatic arthritis, other psoriasis, and osteoporosis. Patients with GPP were more likely to be treated with a combination therapy than those with plaque psoriasis (65.5% vs 21.7%, respectively) and less likely to be treated with a topical medication alone (20.9% vs 50.8%). Patients with GPP had more outpatient visits than patients in the plaque psoriasis or matched control cohorts (mean standard deviation, 14.8 8.3 vs 11.0 7.6 and 7.8 7.2, respectively). They were also more likely to require inpatient hospitalization (24.5% vs 6.4% and 5.0%, respectively). Despite study limitations, patients with GPP in Japan were found to have a higher disease burden, including presence of comorbidities and medication use, than those with plaque psoriasis.