Dialysis Centers With More Commercially Insured Patients Have Lower Mortality Rates, Study Finds

Private insurance plans reimburse for dialysis at far higher rates — some six times higher — than Medicare, research has found. In theory, more revenue per patient can allow centers to pay their physicians, nurses and techs more, enabling them to attract more qualified, competent employees and better maintain their equipment.

A 2022 Supreme Court decision that allows commercial insurers to pay beneficiaries much less could lead many privately insured patients to switch to Medicare.

Researchers at Baylor College of Medicine and Tufts Medical Center wanted to know whether dialysis centers with higher proportions of patients with commercial insurance provide better quality of care than those with lower proportions. If so, then a large-scale shift toward Medicare could harm a lot of people.

Their findings, published May 1 in Kidney Medicine, show that dialysis centers whose payer mixes contained higher percentages of commercial insurance had significantly lower mortality rates than those with lower percentages.

Kevin F. Erickson, M.D., M.S.

Corresponding author Kevin F. Erickson, M.D., M.S., an associate at Baylor’s Selzman Institute for Kidney Health and a nonresident scholar at Rice University's Baker Institute for Public Policy, both in Houston, and colleagues analyzed quality metrics from the CMS’ Facility Reports for 7,194 dialysis facilities in the continental United States with majority adult patient populations in 2019, the last year before the pandemic.

On average, 4.4% of patients had commercial insurance. Each 10% increase in patients with commercial insurance was linked to an 8.3% lower standardized mortality ratio (the ratio of deaths to expected deaths given the patient population).

But none of the six other quality of care metrics yielded statistically significant associations, although two of them (long-term catheter rate and standardized hospitalization ratio) also showed declines.

The authors speculated that their study sample may not have been large enough and the data collection period long enough — just 2019, the last year before the pandemic — to yield statistically significant results on these measures, or that the differences in care quality addressed issues specific to mortality.

But they were clear about their concerns in the wake of the court ruling.

The Supreme Court’s 2022 decision in Marietta Memorial Hospital Employee Health Benefit Plan v. DaVita Inc. allowed commercial health insurers to classify all dialysis facilities as out-of-network, which typically means much lower patient reimbursement rates than for in-network providers. This, the authors wrote, could cause many commercially insured patients who receive dialysis to switch to Medicare as their primary payer.

Cross-sectional studies such as this one can identify associations that may suggest cause-and-effect relationships, but they cannot prove them.

Erickson and his co-authors wrote this in their conclusion: “If the observed association between commercial insurance and mortality reflects a causal connection, then our findings suggest that the effects of the Supreme Court ruling, combined with other cost pressures currently facing US dialysis facilities, could negatively affect care quality and outcomes for dialysis patients. Clinicians, dialysis facility administrators, and policymakers should be aware of the potential effects of this decision on patient care and consider possible mitigation strategies for maintaining patient outcomes.”