Supplementary Material for: Health Care Resource Utilization and Productivity Impairment in Adults With IgA Nephropathy: A Real-World, Observational, Global Analysis

Introduction: There are limited data characterizing the health care resource utilization (HCRU) associated with immunoglobulin A nephropathy (IgAN) and its burden on patients and health care systems. Here, we describe the impact of IgAN on HCRU and productivity using nephrologist- and patient-reported data collected across distinct global geographic regions.

Methods: This was a retrospective, cross-sectional survey of nephrologists managing patients with IgAN (N = 295) and their consulting patients with IgAN (N = 1,792) in the United States, China, and Japan, and France, Germany, Italy, Spain, and the United Kingdom (EU5) between June and October 2021. Data on patient demographics, clinical characteristics, tests/investigations used to diagnose and manage patients, hospitalizations, dialysis, kidney transplantation, and productivity impairment were collected from nephrologist-completed patient record forms and patient self-completion forms. Results were reported using descriptive statistics.

Results: At survey completion, mean (± standard deviation [SD]) patient age was 43.6 (±15.0) years and 58.7% of patients were male. Mean (±SD) estimated glomerular filtration rate was 67.6 (±30.7) mL/min/1.73 m2 and 4.2% of patients were receiving regular dialysis. IgAN was diagnosed by kidney biopsy in 85.8% of patients (range: 79.9 [EU5]–98.2% [Japan]). In the 12 months preceding the survey, patients had a mean (±SD) of 7.1 (±7.7) visits with any health care practitioner and 0.4 (±1.1) IgAN-related hospitalizations. In the 7 days prior to the survey, patients missed 11.8% of their work time, 24.3% of their work was impaired while working, 30.0% of their overall work was impaired, and 32.3% of their daily activities were impaired due to IgAN.

Conclusion: The diagnosis and management of IgAN are associated with a substantial impact on HCRU and productivity across distinct regions. This highlights the unmet need for novel therapies that target the underlying disease pathophysiology to reduce the ongoing HCRU and humanistic burden associated with IgAN.