Credit: Original article published here.
Recent estimates suggest that 37 million adults in the United States, one in seven, have chronic kidney disease (CKD), excluding those with end-stage renal disease. As the population in the United States ages and as the prevalence of risk factors for CKD such as hypertension and obesity increase among all age groups, CKD is expected to become even more common.
CKD is most prevalent among US adults ≥65 years of age; most of the research on the economic burden of CKD has focused on the Medicare population. Excluding patients with ESRD, costs from patients with CKD accounted for more than 22% ($81 billion) of the Medicare fee-for-service spending in 2018. Increasing CKD stage as well as common comorbidities such as heart failure and type 2 diabetes mellitus (T2DM) contribute to cost of care for this patient population.
There are fewer data available on the burden of CKD for commercial payers. Results of some studies have suggested that an increase in all-cause costs due to increasing CKD sages among patients <65 years of age is similar to the observed increases among those ≥65 years of age. However, according to Haechung Chung, MPH, and colleagues, there is a gap in understanding the role of comorbidities in the burden of CKD in patients with commercial health coverage.
The researchers conducted an observational, descriptive retrospective cohort study to describe the economic and health care resource utilization (HCRU) burden of CKD in three patient groups: T2DM only, CKD only, and both T2DM and CKD. Eligible patients were 45 to 64 years of age with commercial health insurance. For patients with CKD only and with CKD and T2DM, the cost burden was also described by Kidney Disease: Improving Global Outcomes (KDIGO) CKD estimated glomerular filtration rate-based stage categories. Results were reported in the Journal of Managed Care & Specialty Pharmacy [2023;29(1):80-89].
The study utilized administrative medical and pharmacy claims integrated into data on laboratory results in the HealthCore Integrated Research (HIRD) database from January 1, 2017, to December 31, 2019. For each of the three study groups, all-cause and disease-specific HCRU and costs in total, by medical and pharmacy benefits and across all places of service, were described for 12 months following the index date.
The HIRD includes adjudicated administrative claims for 14 commercial and Medicare Advantage insurance plans, covering more than 70 million enrollees from all US census regions. A total of 10.3 million members had at least 1 day of health plan enrollment between January 1, 2018, and December 31, 2018. Following application of inclusion and exclusion criteria, the researchers identified three mutually exclusive groups: T2DM only (n=203,576); CKD only (n=22,689); and CKD and T2DM (n=38,587). From those groups, the researchers identified commercially insured members 46 to 64 years of age as of their index date: T2DM only (n=120,364); CKD only (n=7876); and CKD and T2DM (n=13,052).
The three groups were similar in age distribution; mean age was around 56 years for each group. The T2DM only and CKD only groups were similar in sex compositions: 44.5% female in the T2DM only group and 43.2% female in the CKD only group. The proportion of female patients was slightly lower in the CKD and T2DM group (39.7%). In all three groups the majority of participants resided in the Midwest and South regions of the United States (26.5% and 42.0% in the T2DM only group, 25.2% and 40.1% in the CKD only group, and 26.3% and 41.2% in the CKD and T2DM group, respectively).
The CKD and T2DM group had the highest crude baseline comorbidity burden, followed by the CKD only group and the T2DM only group (Quan Enhanced-Charlson Comorbidity Index ≥3: 19.8%, 11.3%, and 4.2%). Across the three groups, the most prevalent comorbid conditions were hypertension, dyslipidemia, and obesity. Cardiovascular conditions were twice as prevalent in the CKD and T2DM group compared with the T2DM only and CKD only groups.
Across all places of service, the CKD and T2DM group had the highest crude post-index all-cause and CKD/T2DM-related HCRU, followed by the CKD only group and the T2DM only group. The CKD and T2DM group had the highest proportion of patients with at least one hospitalization (19.4% vs 13.3% vs 8.5%), highest proportion of patients with at least one emergency department visit (24.3% vs 19.0% vs 18.6%), highest mean number of outpatient encounters per patient (32.1 vs 27.0 vs 19.9), and highest mean number of prescription fills per patient (32.2 vs 21.9 vs 24.1).
Mean 12-month all-cause costs for the CKD and T2DM group were $35,649, compared with $25,010 for the CKD only group and $16,121 for the T2DM only group. For CKD-T2DM-related costs, the mean total 12-month costs were relatively similar in the T2DM only and CKD only groups ($6388 vs $5086. Costs in the CKD and T2DM group were about two to three times as high as those costs ($16,078).
For both all-cause and CKD/T2DM-related costs, inpatient costs represented the greatest proportion of mean total costs in the CKD only and the CKD and T2DM groups. In the T2DM only group, the greatest proportion of mean total costs were prescription costs.
When stratified according to KDIGO CKD stage, total cost trends were similar. For a given CKD stage, both all-cause and CKD/T2DM-related crude costs for the CKD and T2DM group tended to be greater than costs for the CKD only group. As CKD stage increased, costs tended to increase, with increases beginning at KDIGO stage 3b and higher. For the CKD and T2DM group, mean CKD/T2DM-related costs were lowest at stage 1 ($13,193) and only slightly increased at stage 2 ($16,982) and stage 3a ($17,452). Compared with those earlier stages, costs were substantially higher at stage 3B ($25,234), stage 4 ($27,023), and stage 5 ($59,121). At all stages in the CKD only and the CKD and T2DM groups, all-cause and CKD/T2DM-related medical costs were much higher than pharmacy costs.
Limitations to the study findings cited by the authors included using claims provided by major managed care health plans, the possibility of selection bias, the lack of a washout period, and the descriptive nature of the study.
In conclusion, the researchers said, “To our knowledge, this real-world study was among the first to describe the HCRU and cost burden of CKD with and without T2DM in a commercially insured population. Individuals with CKD and T2DM had substantial burden in terms of HCRU and costs. Additionally, costs began to increase at KDIGO CKD stage 3b and continued increasing in later stages, as quantified by the magnitude described in the study. Therefore, there is an opportunity to reduce the burden of CKD in this population by investing in interventions to prevent or delay CKD disease progression.”
Takeaway Points
- Researchers reported results of a study of health care use and costs across three groups: patients with type 2 diabetes mellitus (T2DM), patients with chronic kidney disease (CKD), and patients with both T2DM and CKD.
- Health care use and costs were highest among those in the group with both T2DM and CKD.
- Health care use and costs increased across Kidney Disease Improving Global Outcomes CKD stages, and increased most rapidly at stage 3b and higher.
