Kidney Failure Attributed to Immunoglobulin A Nephropathy: A USRDS Retrospective Cohort Study of Epidemiology, Treatment Modalities, and Economic Burden
Kidney Medicine – 2023
Impact of Proteinuria and Kidney Function Decline on Health Care Costs and Resource Utilization in Adults With IgA Nephropathy in the United States: A Retrospective Analysis
Journal article
Published on June 25, 2023
Contributors:
Lerma EV, Bensink ME, Thakker KM et al.
Lerma EV, Bensink ME, Thakker KM et al.
DOI:
10.1016/j.xkme.2023.100693
10.1016/j.xkme.2023.100693
Summary
Increased healthcare costs in patients with IgA nephropathy and high-risk proteinuria and worsening kidney function1
Background
IgA nephropathy is among the most common primary glomerular diseases in the US,2 and can progress to kidney failure.3
Current guidelines recommend management of blood pressure and proteinuria in IgA nephropathy to preserve kidney function, and angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs) are recommended as initial therapy.4 Guidelines also consider proteinuria ≥0.75–1 g/day as high risk for progression and recommend reduction of proteinuria to <1 g/day as a therapeutic goal.4
A previous literature review did not find a prevalence estimate of IgA nephropathy for the US,5 and data on the associated economic burden were also scarce.1
Aim
The aim of this study was to estimate the prevalence of IgA nephropathy in the US, describe the characteristics of this population and estimate healthcare resource utilization and costs for patients stratified by proteinuria level and chronic kidney disease (CKD) stage.1
Approach
A retrospective cohort study was performed using the Optum database of electronic health record data including claims and prescription data from January 2007 to March 2021.1 Patients in the prevalence cohort were identified based on disease and symptom entries related to IgA nephropathy, with index date defined as the first IgA nephropathy-related entry within the study period.1 The healthcare resource utilization cohort was a subset of the prevalence cohort, of which patients also had to be ≥18 years old at index date, have ≥6 months of enrollment pre- and post-index, and have linked claims data.1
Findings
Baseline demographics (Prevalence cohort: n=9,984)1
- Age: 44.9 years (91.9% aged ≥18 years)
- Median follow-up: 44 months
- Male: 57%
- Median proteinuria: 1.2 g/day
- Median estimated glomerular filtration rate (eGFR): 56.3 mL/min per 1.73m2
Prevalence of IgA nephropathy
The average estimated prevalence of IgA nephropathy in the US was 329.0 per 1,000,000.1
An increase in prevalence was observed over the study period (2016–2000).1
Healthcare resource utilization and cost/resource use cohort (n=813)1
High-risk proteinuria is associated with higher resource use and costs1
Healthcare resource usage of patients with high-risk proteinuria (≥1 g/day) vs <1 g/day1:
- Outpatient visits (mean per patient per month [PPPM]): 3.49 vs 1.74; (P=0.01)
- Pharmacy claims (mean PPPM): 3.79 vs 2.41; (P=0.01)
- Patients with an inpatient stay: 32.3% vs 16.9%; (P=0.03)
There was a consistent trend towards higher costs associated with high-risk proteinuria across various elements of cost.1
Significantly higher outpatient costs and total costs were found for high-risk proteinuria patients vs <1 g/day1:
- Outpatient costs (mean, PPPM): $1,848 vs $682; (P<0.01)
- Total costs (mean, PPPM): $3,732 vs $1,457; (P=0.01)
Higher CKD stage is associated with higher resource use and costs1
Similar differences were associated with higher CKD stages vs lower1:
- Outpatient visits (mean, PPPM): 1.94 Stage 1 vs 8.01 Stage 5 (P<0.001)
- Total costs (mean, PPPM): $2,111 Stage 1 vs $10,703 Stage 5 (P<0.001)
Key takeaway
Considering the rising prevalence of IgA nephropathy, treatments that can reduce proteinuria in IgA nephropathy and preserve kidney function may help reduce resource usage and healthcare costs.1
Related Content
Kidney Failure Attributed to Immunoglobulin A Nephropathy: A USRDS Retrospective Cohort Study of Epidemiology, Treatment Modalities, and Economic Burden
Kidney Medicine – 2023
Footnotes
ACEi, angiotensin-converting enzyme inhibitor; ARB, angiotensin receptor blocker; CKD, chronic kidney disease; eGFR, estimated glomerular filtration rate; PPPM, per patient per month; US, United States.
- Lerma EV et al. Kidney Med. 2023;5(9):100693.
- McGrogan A et al. Nephrol Dial Transplant. 2011;26(2):414-430.
- Nasri H, Mubarak M. J Nephropathol. 2015;4(1):1-5.
- Kidney Disease: Improving Global Outcomes (KDIGO) Glomerular Diseases Work Group. Kidney Int. 2021;100(4S):S1-S276.
- Kwon CS et al. Health Econ Outcomes Res. 2021;8(2):36-45.
MA-DS-24-0033 | September 2024