Scalable kernel balancing weights in a nationwide observational study of hospital profit status and heart attack outcomes.

Weighting is a general and often-used method for statistical adjustment. Weighting has two objectives: first, to balance covariate distributions, and second, to ensure that the weights have minimal dispersion and thus produce a more stable estimator. A recent, increasingly common approach directly optimizes the weights toward these two objectives.

Examining sources of post-acute care inequities with layered target matching.

Objective: To examine factors associated with racial inequities in discharge location, skilled nursing facility (SNF) utilization, and readmissions.

Data Sources: A 20% sample of longitudinal Medicare claims from 2016 to 2018.

Study Design: We present layered target matching, a method for studying sources of inequities.

Alzheimer's Dementia After Exposure to Anesthesia and Surgery in the Elderly: A Matched Natural Experiment Using Appendicitis.

Objective: The aim of this study was to determine whether surgery and anesthesia in the elderly may promote Alzheimer disease and related dementias (ADRD).

Background: There is a substantial conflicting literature concerning the hypothesis that surgery and anesthesia promotes ADRD. Much of the literature is confounded by indications for surgery or has small sample size.

Evaluating the Costs and Outcomes of Hospital Nursing Resources: a Matched Cohort Study of Patients with Common Medical Conditions.

Background: Nursing resources, such as staffing ratios and skill mix, vary across hospitals. Better nursing resources have been linked to better patient outcomes but are assumed to increase costs. The value of investments in nursing resources, in terms of clinical benefits relative to costs, is unclear.

Valuing hospital investments in nursing: multistate matched-cohort study of surgical patients.

Background: There are known clinical benefits associated with investments in nursing. Less is known about their value.

Aims: To compare surgical patient outcomes and costs in hospitals with better versus worse nursing resources and to determine if value differs across these hospitals for patients with different mortality risks.

Comparing Outcomes and Costs of Medical Patients Treated at Major Teaching and Non-teaching Hospitals: A National Matched Analysis.

Background: Teaching hospitals typically pioneer investment in new technology and cultivate workforce characteristics generally associated with better quality, but the value of this extra investment is unclear.

Objective: Compare outcomes and costs between major teaching and non-teaching hospitals by closely matching on patient characteristics.

Design: Medicare patients at 339 major teaching hospitals (resident-to-bed (RTB) ratios ≥ 0.

Comparing Outcomes and Costs of Surgical Patients Treated at Major Teaching and Nonteaching Hospitals: A National Matched Analysis.

Objective: To compare outcomes and costs between major teaching and nonteaching hospitals on a national scale by closely matching on patient procedures and characteristics.

Background: Teaching hospitals have been shown to often have better quality than nonteaching hospitals, but cost and value associated with teaching hospitals remains unclear.

Methods: A study of Medicare patients at 340 teaching hospitals (resident-to-bed ratios ≥ 0.

A National Comparison of Operative Outcomes of New and Experienced Surgeons.

Objective: To determine whether outcomes achieved by new surgeons are attributable to inexperience or to differences in the context in which care is delivered and patient complexity.

Background: Although prior studies suggest that new surgeon outcomes are worse than those of experienced surgeons, factors that underlie these phenomena are poorly understood.

Methods: A nationwide observational tapered matching study of outcomes of Medicare patients treated by new and experienced surgeons in 1221 US hospitals (2009-2013).

Disparities in Breast Cancer Survival by Socioeconomic Status Despite Medicare and Medicaid Insurance.

Unlabelled: Policy Points Patients with low socioeconomic status (SES) experience poorer survival rates after diagnosis of breast cancer, even when enrolled in Medicare and Medicaid. Most of the difference in survival is due to more advanced cancer on presentation and the general poor health of lower SES patients, while only a very small fraction of the SES disparity is due to differences in cancer treatment. Even when comparing only low- versus not-low-SES whites (without confounding by race) the survival disparity between disparate white SES populations is very large and is associated with lower use of preventive care, despite having insurance.

Twelve-Month Outcomes After Transplant of Hepatitis C-Infected Kidneys Into Uninfected Recipients: A Single-Group Trial.

Background: Organs from hepatitis C virus (HCV)-infected deceased donors are often discarded. Preliminary data from 2 small trials, including THINKER-1 (Transplanting Hepatitis C kidneys Into Negative KidnEy Recipients), suggested that HCV-infected kidneys could be safely transplanted into HCV-negative patients. However, intermediate-term data on quality of life and renal function are needed to counsel patients about risk.

Defining Multimorbidity in Older Surgical Patients.

Background: There are numerous definitions of multimorbidity (MM). None systematically examines specific comorbidity combinations accounting for multiple testing when exploring large datasets.

Objectives: Develop and validate a list of all single, double, and triple comorbidity combinations, with each individual qualifying comorbidity set (QCS) more than doubling the odds of mortality versus its reference population.

Adjustment for Atherosclerosis Diagnosis Distorts the Effects of Percutaneous Coronary Intervention and the Ranking of Hospital Performance.

Background: Coronary atherosclerosis raises the risk of acute myocardial infarction (AMI), and is usually included in AMI risk-adjustment models. Percutaneous coronary intervention (PCI) does not cause atherosclerosis, but may contribute to the notation of atherosclerosis in administrative claims. We investigated how adjustment for atherosclerosis affects rankings of hospitals that perform PCI.

Failure-to-Rescue After Acute Myocardial Infarction.

Background: Failure-to-rescue (FTR), originally developed to study quality of care in surgery, measures an institution's ability to prevent death after a patient becomes complicated.

Objectives: Develop an FTR metric modified to analyze acute myocardial infarction (AMI) outcomes.

Research Design: Split-sample design: a random 20% of hospitals to develop FTR definitions, a second 20% to validate test characteristics, and an out-of-sample 60% to validate results.

Comparing Outcomes between Antibody Induction Therapies in Kidney Transplantation.

Kidney transplant recipients often receive antibody induction. Previous studies of induction therapy were often limited by short follow-up and/or absence of information about complications. After linking Organ Procurement and Transplantation Network data with Medicare claims, we compared outcomes between three induction therapies for kidney recipients.

Indirect Standardization Matching: Assessing Specific Advantage and Risk Synergy.

Objective: To develop a method to allow a hospital to compare its performance using its entire patient population to the outcomes of very similar patients treated elsewhere.

Data Sources/setting: Medicare claims in orthopedics and common general, gynecologic, and urologic surgery from Illinois, New York, and Texas from 2004 to 2006.

Study Design: Using two example "focal" hospitals, each hospital's patients were matched to 10 very similar patients selected from 619 other hospitals.

Comparison of the Value of Nursing Work Environments in Hospitals Across Different Levels of Patient Risk.

Importance: The literature suggests that hospitals with better nursing work environments provide better quality of care. Less is known about value (cost vs quality).

Objectives: To test whether hospitals with better nursing work environments displayed better value than those with worse nursing environments and to determine patient risk groups associated with the greatest value.

Examining Causes of Racial Disparities in General Surgical Mortality: Hospital Quality Versus Patient Risk.

Background: Racial disparities in general surgical outcomes are known to exist but not well understood.

Objectives: To determine if black-white disparities in general surgery mortality for Medicare patients are attributable to poorer health status among blacks on admission or differences in the quality of care provided by the admitting hospitals.

Research Design: Matched cohort study using Tapered Multivariate Matching.

Racial disparities in colon cancer survival: a matched cohort study.

Background: Differences in colon cancer survival by race are a recognized problem among Medicare beneficiaries.

Objective: To determine to what extent the racial disparity in survival is due to disparity in presentation characteristics at diagnosis or disparity in subsequent treatment.

Design: Black patients with colon cancer were matched with 3 groups of white patients: a "demographic characteristics" match controlling for age, sex, diagnosis year, and Survey, Epidemiology, and End Results (SEER) site; a "presentation" match controlling for demographic characteristics plus comorbid conditions and tumor characteristics, including stage and grade; and a "treatment" match, including presentation variables plus details of surgery, radiation, and chemotherapy.

A hospital-specific template for benchmarking its cost and quality.

Objective: Develop an improved method for auditing hospital cost and quality tailored to a specific hospital's patient population.

Data Sources/setting: Medicare claims in general, gynecologic and urologic surgery, and orthopedics from Illinois, New York, and Texas between 2004 and 2006.

Study Design: A template of 300 representative patients from a single index hospital was constructed and used to match 300 patients at 43 hospitals that had a minimum of 500 patients over a 3-year study period.

Template matching for auditing hospital cost and quality.

Objective: Develop an improved method for auditing hospital cost and quality.

Data Sources/setting: Medicare claims in general, gynecologic and urologic surgery, and orthopedics from Illinois, Texas, and New York between 2004 and 2006.

Study Design: A template of 300 representative patients was constructed and then used to match 300 patients at hospitals that had a minimum of 500 patients over a 3-year study period.

Characteristics associated with differences in survival among black and white women with breast cancer.

Importance: Difference in breast cancer survival by race is a recognized problem among Medicare beneficiaries.

Objective: To determine if racial disparity in breast cancer survival is primarily attributable to differences in presentation characteristics at diagnosis or subsequent treatment.

Design, Setting, And Patients: Comparison of 7375 black women 65 years and older diagnosed between 1991 to 2005 and 3 sets of 7375 matched white control patients selected from 99,898 white potential controls, using data for 16 US Surveillance, Epidemiology and End Results (SEER) sites in the SEER-Medicare database.