OBJECTIVES: Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide, with an annual incidence of ~25/1000000. Here, we describe the socioeconomic burden of IgAN, through the work productivity, and activity impairment (WPAI) questionnaire.

METHODS: The Adelphi IgAN Disease Specific Programme™ was a point-in-time survey of IgAN-treating nephrologists and their patients in the US, and France, Germany, Italy, Spain, UK (EU5), Japan, and China, June-October 2021. Nephrologists completed online records for successive patients with IgAN, including clinical characteristics and patients’ insurance coverage. Patients reported disease impact on work and routine activities, including the WPAI general health questionnaire. Analyses were descriptive.

RESULTS:

Nephrologists completed records for 883 patients, with known proteinuria at survey and corresponding patient-reported WPAI (US n=67, EU5 n=176, Japan n=98, China n=542). Mean patient age was 42 years, 56% were male. Median time since IgAN diagnosis was 3.3 years (US 4.0, EU5 5.0, Japan 4.2, China 2.5).

At survey, 37% of patients had proteinuria ≥1 g/day (US 66%, EU5 43%, Japan 16%, China 35%). 88% had health insurance that covered treatment for IgAN.

Mean patient-reported work time missed in patients with proteinuria ≥1 g/day vs <1 g/day was US 10.5% vs 0.4%, EU5 8.2% vs 8.3%, Japan 19.9% vs 3.5%, China 20.5% vs 12.7%. Mean percentage impairment while working in patients with proteinuria ≥1 g/day vs <1 g/day was US 31.8% vs 9.4%, EU5 16.9% vs 8.7%, Japan 37.5% vs 15.3%, China 37.0% vs 26.4%. Differences in impairment of daily activities were noted, with ≥1 g/day vs <1 g/day: US 36.4% vs 14.3%, EU5 25.1% vs 11.7%, Japan 41.2% vs 22.1%, China 47.6% vs 33.7%.

CONCLUSIONS: IgAN patients with ≥1 g/day proteinuria may experience greater WPAI burden than patients with <1 g/day. This impact on patient’s work productivity and daily impairment highlights the need for effective therapies.