Market Competition and Anemia Management in the United States Following Dialysis Payment Reform

BACKGROUND

Whether market competition influences health care provider responses to national reimbursement reforms is unknown.

OBJECTIVES

We examined whether changes in anemia management after the expansion of Medicare's dialysis payment bundle varied with market competition.

RESEARCH DESIGN

With data from the US dialysis registry, we used a difference-in-differences (DID) design to estimate the independent associations of market competition with changes in anemia management after dialysis reimbursement reform.

SUBJECTS

A total of 326,150 patients underwent in-center hemodialysis in 2009 and 2012, representing periods before and after reimbursement reform.

MEASURES

Outcomes were erythropoiesis-stimulating agent (ESA) and intravenous iron dosage, the probability of hemoglobin <9 g/dL, hospitalizations, and mortality. We also examined serum ferritin concentration, an indicator of body iron stores. We used a dichotomous market competition index, with less competitive areas defined as effectively having <2 competing dialysis providers.

RESULTS

Compared with areas with more competition, patients in less competitive areas had slightly more pronounced declines in ESA dose (60% vs. 57%) following reimbursement reform (DID estimate: -3%; 95% CI, -5% to -1%) and less pronounced declines in intravenous iron dose (-14% vs. -19%; DID estimate: 5%; 95% CI, 1%-9%). The likelihoods of hemoglobin <9 g/dL, hospitalization, and mortality did not vary with market competition. Serum ferritin concentrations in 2012 were 4% (95% CI, 3%-6%) higher in less competitive areas.

CONCLUSIONS

After the expansion of Medicare's dialysis payment bundle, ESA use declined by more, and intravenous iron use declined by less in concentrated markets. More aggressive cost-reduction strategies may be implemented in less competitive markets.

Infliximab for Treatment of Immune Adverse Events and Its Impact on Tumor Response

Background: Immune-related adverse events (irAEs) challenge the use of immune checkpoint inhibitors (ICIs). We performed a retrospective study to evaluate response to infliximab for immune-related adverse event management, and infliximab's effect on progression-free survival (PFS) and overall survival (OS) with a focus on melanoma and genitourinary cancers. Methods: We retrospectively reviewed records of all cancer patients exposed to infliximab after immune checkpoint inhibitor (ICI) treatment from 2004 to 2021 at the MD Anderson Cancer Center. Survival was assessed utilizing the Kaplan-Meier method. Univariate and multivariate logistic regression was utilized to evaluate predictors of infliximab response, OS, and PFS. Results: We identified 185 cancer patients (93 melanoma and 37 genitourinary cancers) treated with ICI and who received infliximab to treat irAEs. Within 3 months of treatment initiation, 71% of the patients responded to infliximab, 27% had no response, and 2% had unknown response. Among different irAEs, colitis was associated with increased response to infliximab at 3 months, irrespective of the type of malignancy. We evaluated best tumor response before and after infliximab in the entire cohort and again in the melanoma and genitourinary (GU); the findings were similar in the melanoma cohort and the entire cohort, where best tumor response before and after infliximab was not significantly different. In the melanoma cohort, acute kidney injury (AKI) was associated with increased risk of death, p = 0.0109, and having response to infliximab was associated with decreased risk of death, p = 0.0383. Interestingly in GU cancer patients, myositis was associated with increased risk of death, p = 0.0041, and having a response to infliximab was marginally associated with decreased risk of death, p = 0.0992. As regards PFS, in a multivariate Cox regression model, having a history of cardiovascular disease remained significantly associated with shorter PFS in the melanoma cohort. For patients with GU cancers, response to infliximab was associated with longer PFS. Conclusions: Our study is among the largest retrospective analyses of infliximab use for irAE management. Patients with colitis were the best responders to infliximab. AKI before initiation of infliximab in the melanoma subcohort and myositis in GU subcohort are associated with higher risk of death. Our results indicate no association between infliximab and cancer progression with the exception of genitourinary cancers.