This cohort study examines whether market-level academic medical center presence is associated with outcomes for Medicare patients treated at nonteaching hospitals within the same markets.

This cross-sectional study assesses whether the increase in adult and pediatric and neonatal mechanical ventilators in US hospitals in response to the COVID-19 pandemic varied across hospital structural features, region, and safety-net status.

This cross-sectional study examines changes in mortality rates over time in White and Black patients undergoing surgery for cancer.

This cross-sectional study examines whether Medicaid expansion is associated with improved mortality among patients with breast, colorectal, and lung cancer.

This study evaluates COVID-19 case rates between high- and low-performing nursing homes based on CMS quality measures.

This cross-sectional study examines trends in total standardized 30-day costs of care associated with an emergency department visit among Medicare beneficiaries.

This Viewpoint introduces the notion of a polysocial risk score, much like a polygenic risk score, which might help predict the risk that varying combinations of social conditions contribute to specific health outcomes.

This cohort study determines the proportion and degree of total spending directly associated with mental health conditions vs spending on other non–mental health conditions among Medicare beneficiaries in the US.

This cross-sectional study examines trends in 30-day mortality rates associated with care in the emergency department among Medicare beneficiaries aged 65 years or older.

This study of Medicare-defined avoidable hospital stays for conditions such as urinary tract infection and complications of diabetes uses Medicare Fee-for-Service Inpatient and Outpatient Claim Files to investigate whether a decrease in inpatient admissions from 2011 to 2015 represented real gains in ambulatory care.

In the context of limited evidence to date that national health care quality improvement (QI) initiatives are effective, this Viewpoint proposes shifting the focus of QI efforts to high-need, high-cost individuals, such as frail older patients and those at the end of life, because they are especially vulnerable to adverse consequences of low-value, high-cost care.

This study of 100% Medicare Inpatient Files assesses strategies for managing coding of comorbidities associated with hospitalization before and after Centers for Medicare & Medicaid coding changes.

This cross-sectional study compares the 30-day costs of care for common conditions among US Medicare beneficiaries by hospital teaching status.