Health, Economic Burden of Comorbid Gout, CKD Projected to Increase Through 2035

Joshua Card-Gowers, MSc

Credit: Joshua Card-Gowers on LinkedIn

Findings from a recent microsimulation study are sounding the alarm on projected increases in the prevalence of comorbid gout and chronic kidney disease (CKD) through 2035, driven primarily by population aging and CKD progression.¹

Results showed a projected 29% increase in the prevalence of comorbid gout and CKD from 2023 to 2035, also highlighting a subsequent 21.8% increase in both direct and indirect costs for patients during this time frame.¹

The US Centers for Disease Control and Prevention estimates about 35.5 million US adults have CKD, while an estimated 8.3 million US adults have gout.^2,3 CKD and gout are bidirectionally related – reduced kidney function in CKD can lead to a buildup of uric acid causing gout, and the excess of uric acid associated with gout is also believed to cause kidney damage potentially leading to kidney disease or failure over time.⁴

“Chronic kidney disease and gout are both prevalent and interrelated conditions with significant public health implications,” Joshua Card-Gowers, MSc, senior evidence lead at HealthLumen, and colleagues wrote.¹ “Data on the current health and economic burden of gout in the chronic kidney disease population is sparse. Moreover, the future health and economic burden of comorbid gout and CKD is unknown.”

Investigators used a validated microsimulation model to estimate the current and future health and economic burden of controlled and uncontrolled gout in patients with CKD in the US through 2035. Databases were utilized to build a virtual population, with modeling assumptions based on available literature.¹

For the first year of the simulation, investigators assigned each virtual individual an age, sex, urinary albumin creatinine ratio (UACR), estimated glomerular filtration rate (eGFR), serum urate level, gout status, baseline disease status, and relative risk of future disease development. The virtual population reflected key characteristics of the US population in 2023 and comprised 200 million individuals, later scaled to match the true size of the US population in 2023 and the projected population size thereafter.¹

UACR and eGFR were determined based on age and sex-aggregated data extracted from the 2018 National Health and Nutrition Examination Survey (NHANES) and simulated dynamically to account for changes in each parameter as age increased. These values were then used to assign each individual a CKD stage using the Kidney Disease Improving Global Outcomes classification.¹

Serum urate level data were extracted from the NHANES database and grouped by age, sex, and CKD stage, again simulated dynamically to account for advances in age and changes in CKD stage. The probability of having gout based on serum urate level was also extracted from the NHANES study and grouped by sex and CKD stage.¹

Based on prevalence data for age and sex, individuals were assigned a probability of having a comorbidity, including hypertension, type 2 diabetes, coronary heart disease, and/or stroke at the start of the simulation. Each subsequent year, individuals were assigned a risk of developing an incident gout-associated comorbidity based on incidence statistics by age and sex as well as relative risks based on serum urate level.¹

Based on the model, investigators projected the number of people living with CKD would grow by 17.1% between 2023 and 2035, increasing from 51.6 million to 60.5 million. The number of people living with advanced CKD (stages 3–5) was projected to increase by 35.8% from 21.5 million in 2023 to 29.2 million in 2035. Of note, the prevalence of comorbid gout and CKD was projected to increase by 29%, from 7.9 million in 2023 to 9.6 million in 2035.¹

Further analysis revealed a 22.2% increase in projected gout flares experienced in the comorbid gout-CKD population each year, from 5.0 million in 2023 to 6.15 million in 2035. Gout-associated complications were projected to rise between 2023 and 2035, with the simulation predicting 964,100 new cases of coronary heart disease, 908,700 new cases of hypertension, 764,600 new cases of type 2 diabetes, and 441,400 new strokes through 2035.¹

The annual direct and indirect costs of gout in patients with CKD were $38.9 billion in 2023, increasing by 21.8% to $47.3 billion in 2035. Investigators pointed out nearly half of the $568.1 billion cumulative cost over the entire simulation time frame was associated with uncontrolled gout, also noting a large contributor to the indirect costs of uncontrolled gout was the number of working days missed annually.¹

Administering an oral urate-lowering therapy to all individuals with uncontrolled gout in this virtual CKD population led to approximately 613,000 fewer cases of uncontrolled gout in 2023 and 744,000 fewer cases in 2035. A projected 118,200 fewer incident complications occurred with oral urate-lowering therapy intervention between 2023 and 2035, and 557,000 QALYs were gained through 2035. Widespread oral urate-lowering therapy use was projected to lead to direct and indirect cost savings of $58.4 billion through 2035.¹

Similarly, administering pegloticase with immunomodulator co-therapy in patients with refractory gout was projected to result in approximately 292,000 fewer cases of uncontrolled gout in 2023 and 353,000 fewer cases in 2035. Between 2023 and 2035, a projected 53,600 fewer incident complications occurred with pegloticase intervention, and 273,000 QALYs were gained. Use of pegloticase with immunomodulator co-therapy reduced the direct and indirect costs associated with gout by $27.8 billion through 2035.¹

Investigators outlined several potential limitations to these findings, including their reliance on modeling epidemiological assumptions where evidence was not available in the literature; the use of relative risks based on serum urate data; the assumption that all individuals were eligible for and remained on medication through the end of the simulation; and the lack of a consistent definition for uncontrolled gout.¹

“This study demonstrates the large current and potential future health and economic burden of gout in a virtual US CKD population,” investigators concluded.¹

References:

1. ^{Card-Gowers J, Retat L, Kumar A, et al. Projected Health and Economic Burden of Comorbid Gout and Chronic Kidney Disease in a Virtual US Population: A Microsimulation Study. Rheumatol Ther (2024). https://doi.org/10.1007/s40744-024-00681-2}
2. ^{US Centers for Disease Control and Prevention. Chronic Kidney Disease in the United States, 2023. May 15, 2024. Accessed June 12, 2024. https://www.cdc.gov/kidney-disease/php/data-research/index.html}
3. ^{National Kidney Foundation. Quick Facts: Gout and Chronic Kidney Disease. Accessed June 12, 2024. https://www.kidney.org/atoz/content/gout/patient-facts}
4. ^{American Kidney Fund. Gout and kidney disease. May 7, 2024. Accessed June 12, 2024. https://www.kidneyfund.org/living-kidney-disease/health-problems-caused-kidney-disease/gout/gout-and-kidney-disease}