Effect of patient death on referrals to cardiac specialists.

In this paper, I examine how patient death affects referrals from referring physicians to cardiac surgeons. I use Medicare data to identify pairs of referring physicians and cardiac surgeons who experience a patient death after a major surgical procedure to examine how these events affect referrals. I construct counterfactuals for affected pairs using pairs that experience a patient death but five quarters in the future. I find that there is a significant decline in the number of referrals and probability of a referral from the referring physician to the cardiac surgeon after the patient's death.

Estimates of diagnosed dementia prevalence and incidence among diverse beneficiaries in traditional Medicare and Medicare Advantage.

Approximately half of Medicare beneficiaries are enrolled in Medicare Advantage (MA), a private plan alternative to traditional Medicare (TM). Yet little is known about diagnosed dementia rates among MA enrollees, limiting population estimates. All (100%) claims of Medicare beneficiaries using encounter data for MA and claims for TM for the years 2015 to 2018 were used to quantify diagnosed dementia prevalence and incidence rates in MA, compare rates to TM, and provide estimates for the entire Medicare population and for different racial/ethnic populations. In 2017, dementia incidence and prevalence among MA beneficiaries were 2.54% (95% confidence interval [CI]: 2.53 to 2.55) and 7.04% (95% CI: 7.03 to 7.06). Comparison to TM adjusted for sociodemographic and health differences among beneficiaries in MA and TM; the prevalence of diagnosed dementia among beneficiaries in MA was lower (7.1%; 95% CI: 7.12 to 7.13) than in TM (8.7%; 95% CI: 8.71 to 8.72). The diagnosed dementia incidence rate was also lower in MA (2.50%; 95% CI: 2.50 to 2.50) compared to TM (2.99%; 95% CI: 2.99 to 2.99). There were lower rates in MA compared to TM for men and women and White, Black, Hispanic, Asian, American Indian/Alaska Native persons. Diagnosed dementia prevalence and incidence for the entire Medicare population was 7.9% (95% CI: 7.91 to 7.93) and 2.8% (95% CI: 2.77 to 2.78). Lower diagnosed dementia rates in MA compared to TM may exacerbate racial/ethnic disparities in diagnosed dementia. Rates tracked over time will provide understanding of the impact on dementia diagnosis of 2020 MA risk adjustment for dementia.

Medicare Advantage: A Disadvantage for Complex Cancer Surgery Patients.

PURPOSE: Nearly half of all Medicare beneficiaries are enrolled in privatized Medicare insurance plans (Medicare Advantage [MA]). Little comparative information is available about access, outcomes, and cost of inpatient cancer surgery between MA and Traditional Medicare (TM) beneficiaries. We set out to assess and compare access, postoperative outcomes, and estimated cost of inpatient cancer surgery among MA and TM beneficiaries. METHODS: Retrospective cohort analysis of MA or TM beneficiaries undergoing elective inpatient cancer surgery (for cancers located in lung, esophagus, stomach, pancreas, liver, colon, or rectum) was performed using the Office of Statewide Health Planning Inpatient Database linked to California Cancer Registry from 2000 to 2020. For each cancer site, risk-standardized access to high-volume hospitals, postoperative 30-day mortality, complications, failure to rescue, and surgery-specific estimated costs were compared between MA and TM beneficiaries. RESULTS: This analysis of 76,655 Medicare beneficiaries (median age 74 years, 51% female, 39% MA) included 31,913 colectomies, 10,358 proctectomies, 4,604 hepatectomies, 2,895 pancreatectomies, 3,639 gastrectomies, 1,555 esophagectomies, and 21,691 lung resections. Except for colon surgery, MA beneficiaries were less likely to receive care at a high-volume hospital. Mortality was significantly higher among MA beneficiaries (v TM) for gastrectomy (adjusted risk difference [ARD], 1.5%; 95% CI, 0.01 to 2.9; P = .036), pancreatectomy (ARD, 2.0%; CI, 0.80 to 3.3; P = .002), and hepatectomy (ARD, 1.4%; 95% CI, 0.1 to 2.9; P = .04). By contrast, compared with TM, MA beneficiaries incurred lower estimated hospital costs. CONCLUSION: Enrollment in MA plan is associated with lower estimated hospital costs. However, compared with TM, MA beneficiaries had lower access to high-volume hospitals and increased 30-day mortality for stomach, pancreas, or liver surgery.

Systematic failure to operate on colorectal cancer liver metastases in California.

BACKGROUND: Despite evidence that liver resection improves survival in patients with colorectal cancer liver metastases (CRCLM) and may be potentially curative, there are no population-level data examining utilization and predictors of liver resection in the United States. METHODS: This is a population-based cross-sectional study. We abstracted data on patients with synchronous CRCLM using California Cancer Registry from 2000 to 2012 and linked the records to the Office of Statewide Health Planning Inpatient Database. Quantum Geographic Information System (QGIS) was used to map liver resection rates to California counties. Patient- and hospital-level predictors were determined using mixed-effects logistic regression. RESULTS: Of the 24 828 patients diagnosed with stage-IV colorectal cancer, 16 382 (70%) had synchronous CRCLM. Overall liver resection rate for synchronous CRCLM was 10% (county resection rates ranging from 0% to 33%) with no improvement over time. There was no correlation between county incidence of synchronous CRCLM and rate of resection (R2  = .0005). On multivariable analysis, sociodemographic and treatment-initiating-facility characteristics were independently associated with receipt of liver resection after controlling for patient disease- and comorbidity-related factors. For instance, odds of liver resection decreased in patients with black race (OR 0.75 vs white) and Medicaid insurance (OR 0.62 vs private/PPO); but increased with initial treatment at NCI hospital (OR 1.69 vs Non-NCI hospital), or a high volume (10 + cases/year) (OR 1.40 vs low volume) liver surgery hospital. CONCLUSION: In this population-based study, only 10% of patients with liver metastases underwent liver resection. Furthermore, the study identifies wide variations and significant population-level disparities in the utilization of liver resection for CRCLM in California.

Liver Resection Improves Survival in Colorectal Cancer Patients: Causal-effects From Population-level Instrumental Variable Analysis.

OBJECTIVE: The aim of this study was to estimate population-level causal effects of liver resection on survival of patients with colorectal cancer liver metastases (CRC-LM). BACKGROUND: A randomized trial to prove that liver resection improves survival in patients with CRC-LM is neither feasible nor ethical. Here, we test this assertion using instrumental variable (IV) analysis that allows for causal-inference by controlling for observed and unobserved confounding effects. METHODS: We abstracted data on patients with synchronous CRC-LM using the California Cancer Registry from 2000 to 2012 and linked the records to the Office of Statewide Health Planning and Development Inpatient Database. We used 2 instruments: resection rates in a patient's neighborhood (within 50-mile radius)-NALR rate; and Medical Service Study Area resection rates-MALR rate. IV analysis was performed using the 2SLS method. RESULTS: A total of 24,828 patients were diagnosed with stage-IV colorectal cancer of which 16,382 (70%) had synchronous CRC-LM. Liver resection was performed in 1635 (9.8%) patients. NALR rates ranged from 8% (lowest-quintile) to 11% (highest-quintile), whereas MALR rates ranged from 3% (lowest quintile) to 19% (highest quintile). There was a strong association between instruments and probability of liver resection (F-statistic at median cut-off: NALR 24.8; MALR 266.8; P < 0.001). IV analysis using both instruments revealed a 23.6 month gain in survival (robust SE 4.4, P < 0.001) with liver resection for patients whose treatment choices were influenced by the rates of resection in their geographic area (marginal patients), after accounting for measured and unmeasured confounders. CONCLUSION: Less than 10% of patients with CRC-LM had liver resection. Significant geographic variation in resection rates is attributable to community biases. Liver resection leads to extensive survival benefit, accounting for measured and unmeasured confounders.