Healthcare Resource Utilization and Related Costs in Chronic Fibrosing Interstitial Lung Diseases with a Progressive Phenotype: A US Claims Database Analysis

Introduction We aimed to describe healthcare resource utilization (HCRU) patterns and costs in patients with fibrosing interstitial lung disease (ILD) and those with a progressive phenotype of fibrosing ILD in a US claims database. Methods Data from the IBM ® MarketScan ® databases (1 October 2011–30 September 2015) were used. Diagnosis codes documented on medical claims on two occasions (without any claims during the 12 months prior) identified patients with incident fibrosing ILD. Patients with chronic fibrosing ILD with a progressive phenotype were identified by proxies for progression. Patients aged ≥ 18 years with 365 days of continuous coverage before the index date were eligible for inclusion. Data were analyzed for 12 months prior to identification of fibrosing ILD/progressive phenotype (baseline) and 12 months after (follow-up). Outcomes included treatment patterns, outpatient and inpatient claims, and costs. Results We identified 23,577 patients with incident fibrosing ILD and 14,722 with the progressive phenotype. Follow-up data were available for 9986 and 5840 patients, respectively. The most frequent ILD-related medications during baseline were corticosteroids (49.4% and 56.6%). Mean (± standard deviation [SD]) annualized number of outpatient claims was 30.0 (± 26.4) and 34.1 (± 27.7) in the baseline period and 36.2 (± 28.6) and 41.9 (± 30.2) in the follow-up in fibrosing ILD and with a progressive phenotype, respectively. Mean (SD) number of all-cause hospitalizations was 0.5 (± 1.1) and 0.7 (± 1.2) during baseline and 0.6 (± 1.1) and 0.7 (± 1.2) during follow-up. Mean (SD) total costs were $40,907 (± 92,496) and $49,561 (± 98,647) during baseline and $46,157 (± 102,858) and $54,215 (± 116,833) during follow-up. Inpatient mortality during follow-up was 53.50 and 77.44 per 1000 patient-years. Conclusion HCRU and costs were high in patients with chronic fibrosing ILD with a progressive phenotype, likely reflecting the disease severity and the need for close monitoring and acute care. Outpatient claims accounted for a substantial proportion of the total costs.