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. However, this approach has not yet been feasible in large-scale datasets when investigators wish to flexibly balance general basis functions in an extended feature space. To address this practical problem, we describe a scalable and flexible approach to weighting that integrates a basis expansion in a reproducing kernel Hilbert space with state-of-the-art convex optimization techniques. Specifically, we use the rank-restricted Nyström method to efficiently compute a kernel basis for balancing in nearly linear time and space, and then use the specialized first-order alternating direction method of multipliers to rapidly find the optimal weights. In an extensive simulation study, we provide new insights into the performance of weighting estimators in large datasets, showing that the proposed approach substantially outperforms others in terms of accuracy and speed. Finally, we use this weighting approach to conduct a national study of the relationship between hospital profit status and heart attack outcomes in a comprehensive dataset of 1.27 million patients. We find that for-profit hospitals use interventional cardiology to treat heart attacks at similar rates as other hospitals but have higher mortality and readmission rates.

Preferences for Postacute Care at Home vs Facilities.

Importance: Two in 5 US hospital stays result in rehabilitative postacute care, typically through skilled nursing facilities (SNFs) or home health agencies (HHAs). However, a lack of clear guidelines and understanding of patient and caregiver preferences make it challenging to promote high-value patient-centered care. Objective: To assess preferences and willingness to pay for facility-based vs home-based postacute care among patients and caregivers, considering demographic variations. Design, Setting, and Participants: In September 2022, a nationally representative survey was conducted with participants 45 years or older. Using a discrete choice experiment, participants acting as patients or caregivers chose between facility-based and home-based postacute care that best met their preferences, needs, and family conditions. Survey weights were applied to generate nationally representative estimates. Main Outcomes and Measures: Preferences and willingness to pay for various attributes of postacute care settings were assessed, examining variation based on demographic factors, socioeconomic status, job security, and previous care experiences. Results: A total of 2077 adults were invited to participate in the survey; 1555 (74.9%) completed the survey. In the weighted sample, 52.9% of participants were women, 6.5% were Asian or Pacific Islander, 1.7% were American Indian or Alaska Native, 11.2% were Black or African American, 78.4% were White; the mean (SD) age was 62.6 (9.6) years; and there was a survey completion rate of 74.9%. Patients and caregivers showed a substantial willingness to pay for home-based and high-quality care. Patients and caregivers were willing to pay an additional $58.08 per day (95% CI, 45.32-70.83) and $45.54 per day (95% CI, 31.09-59.99) for HHA care compared with a shared SNF room, respectively. However, increased demands on caregiver time within an HHA scenario and socioeconomic challenges, such as insecure employment, shifted caregivers' preferences toward facility-based care. There was a strong aversion to below average quality. To avoid below average SNF care, patients and caregivers were willing to pay $75.21 per day (95% CI, 61.68-88.75) and $79.10 per day (95% CI, 63.29-94.91) compared with average-quality care, respectively. Additionally, prior awareness and experience with postacute care was associated with willingness to pay for home-based care. No differences in preferences among patients and caregivers based on race, educational background, urban or rural residence, general health status, or housing type were observed. Conclusions and Relevance: The findings of this survey study underscore a prevailing preference for home-based postacute care, aligning with current policy trends. However, attention is warranted for disadvantaged groups who are potentially overlooked during the shift toward home-based care, particularly those facing caregiver constraints and socioeconomic hardships. Ensuring equitable support and improved quality measure tools are crucial for promoting patient-centric postacute care, with emphasis on addressing the needs of marginalized groups.

Factors Underlying Reduced Hospitalizations for Myocardial Infarction During the COVID-19 Pandemic.

Importance: The incidence of hospital encounters for acute myocardial infarction (AMI) decreased sharply early in the COVID-19 pandemic and has not returned to prepandemic levels. There has been an ongoing debate about what mechanism may underlie this decline, including patients avoiding the hospital for treatment, excess mortality from COVID-19 among patients who would otherwise have had an AMI, a reduction in the incidence or severity of AMIs due to pandemic-related changes in behavior, or a preexisting temporal trend of lower AMI incidence. Objective: To describe drivers of changing incidence in AMI hospital encounters during the COVID-19 pandemic. Design, Setting, and Participants: This cross-sectional study used traditional Medicare claims from all patients enrolled in traditional Medicare from January 2016 to June 2023 (total of 2.85 billion patient-months) to calculate the rate of AMI hospital encounters (emergency department visits, observation stays, or inpatient admissions) per capita at all short-term acute care and critical access hospitals in the United States overall and by patient characteristics. Observed rates were compared with expected rates that accounted for shifts in population characteristics and the prepandemic temporal trend (as estimated over 2016-2019). Data were analyzed in November 2023. Main Outcomes and Measures: Hospital encounters for AMI. Results: On average, the study sample included 31 623 928 patients each month from January 2016 through June 2023, for a total of 2 846 153 487 patient-months during the 90-month study period. In June 2023, there were 0.044 AMI hospital encounters per 100 patients, which was 20% lower than in June 2019 (0.055 encounters per 100 patients). Early in the pandemic, AMI rates moved inversely with COVID-19 death rates and tracked patterns seen for other painful acute conditions, such as nephrolithiasis, suggesting these changes were associated with care avoidance. Changes in patient characteristics driven by excess deaths during the pandemic explained little of the decline. Later in the pandemic, the decline may be explained by the long-standing downward trend in AMI incidence; by April 2022, the observed rate of encounters matched the expected rate that accounted for this trend. During the full pandemic period, from March 2020 to June 2023, there were an estimated 5% (95% prediction interval, 1%-9%) fewer AMI hospital encounters than expected. Conclusions and Relevance: The early reduction in AMI encounters was likely driven by care avoidance, while ongoing reductions through June 2023 likely reflect long-standing temporal trends. During the pandemic, there were 5% fewer AMI encounters than expected.