The effect of silent eating during school lunchtime on COVID-19 outbreaks.

Silent eating-no talking during mealtimes-has been used as a measure to reduce the spread of the COVID-19 infection because the emission of droplets during conversations has been considered a risk factor for spreading the virus. Japan implemented silent eating during school lunchtimes in May 2020, and it remained in effect until November 2022. However, concerns have been raised regarding its potential negative effects on children's well-being and educational attainment. More importantly, no study to date has examined its effectiveness in reducing the risk of COVID-19 outbreaks. This study aims to address this important knowledge gap by examining the impact of silent eating on the risk of COVID-19 outbreaks. In November 2022, the Japanese government announced that silent eating in public schools was no longer needed, which resulted in discontinuation of the measure in some schools while other schools maintained it. Taking advantage of this cancelation of the silent eating requirement as a natural experiment, we investigated whether silent eating was associated with a reduced risk of COVID-19 outbreaks. We measured the probability of class closures in public schools (the government's guidelines required class closure when more than one child was infected with COVID-19) by applying a Difference-in-Differences model with two-way fixed effects to panel data. We found no evidence that silent eating was associated with a reduced probability of class closures. Heterogeneity analysis also revealed that our findings did not vary by school characteristics. Our findings indicate that policymakers should be cautious about using silent eating at schools as a potential lever to control outbreaks of infectious diseases.

Depression Onset After a Spouse's Cardiovascular Event.

Importance: Although cardiovascular disease (CVD) is a known risk factor for depression, evidence is lacking regarding whether and to what extent a spouse's CVD is associated with the subsequent mental health of individuals. Objective: To examine the association between CVD onset in spouses and subsequent depression. Design, Setting, and Participants: This cohort study examined 277 142 matched married couples enrolled in the Japan Health Insurance Association health insurance program between April 2015 and March 2022, covering approximately 40% of the working-age population in Japan. Index individuals (primary insured) whose spouses (dependent) experienced incident CVD between April 2016 and March 2022 were 1:1 matched to controls whose spouses did not experience CVD. Matching was based on age, sex, income, or the onset date of the spouses' CVD. Data analysis was conducted from April 2016 to March 2022. Exposure: Spousal onset of CVD between fiscal years 2016 and 2021. The International Statistical Classification of Diseases and Related Health Problems, Tenth Revision codes were used to identify the composite CVD outcomes (stroke, heart failure, and myocardial infarction). Main Outcomes and Measures: Multivariate Cox proportional hazards models were used to investigate the association between spouses' new-onset CVD and individuals' depression, adjusting for sociodemographic characteristics and comorbidities of index individuals (diabetes, hypertension, and CVD) and spouses (diabetes, hypertension, and depression). Subgroup analyses were conducted according to sex, age, income levels, and history of CVD. Results: Among 277 142 matched pairs of married couples, 263 610 (95.1%) had a male index individual; the mean (SD) age of index individuals was 58.2 (10.2) years. A new onset of depression was observed in 4876 individuals (1.8%). In multivariable Cox models, there was an association between the spouse's CVD and the individuals' depression (hazard ratio, 1.13 [95% CI, 1.07-1.20]). The subgroup analysis found no evidence of heterogeneity in sex, age, income level, or CVD history. The results were consistent when additionally adjusted for health behaviors (smoking, alcohol consumption, physical activity, and use of antihypertensive drugs) and objectively measured physical health conditions (body mass index, blood pressure, cholesterol levels, glucose levels, and estimated glomerular filtration rate) (hazard ratio, 1.16 [95% CI, 1.06-1.28]). Conclusions and Relevance: In this nationwide cohort study of matched couples, a spouse's onset of CVD was associated with an increased risk of an individual's depression. These findings highlight the importance of preventive care for mental health disorders in individuals whose spouses experience incident CVD.

Physician characteristics associated with antiviral prescriptions for older adults with COVID-19 in Japan: an observational study.

OBJECTIVES: Although guidelines recommend antiviral therapy for outpatients with COVID-19 who are at high risk of progressing to severe conditions, such as older adults, many patients do not receive appropriate treatment. Little is known, however, about the physician factors associated with the prescription of guideline-recommended antiviral therapy for patients with COVID-19. DESIGN: A cross-sectional study. SETTING: Data including outpatient visits in primary care clinics in Japan from April to August 2023. PARTICIPANTS: We analysed 30 953 outpatients aged ≥65 years treated with COVID-19 (mean (SD) age, 75.0 (7.6) years; 17 652 women (57.0%)) in 1394 primary care clinics. OUTCOME MEASURES: The primary outcome was the prescription of guideline-recommended antivirals (ie, nirmatrelvir-ritonavir or molnupiravir), adjusted for patient characteristics, months of visits and regions. RESULTS: Antiviral prescriptions were concentrated among a small proportion of physicians; for example, the top 10% of physicians that had the largest number of nirmatrelvir-ritonavir prescriptions accounted for 92.4% of all nirmatrelvir-ritonavir prescriptions. After adjusting for potential confounders, physicians with higher patient volumes were more likely to prescribe guideline-recommended antivirals to their patients (adjusted OR (aOR) for high vs low volume, 1.76; 95% CI 1.31 to 2.38; adjusted p<0.001). We found no evidence that the likelihood of guideline-recommended antiviral prescription differed based on physicians' gender (aOR for women vs men, 1.24; 95% CI 0.88 to 1.74; adjusted p=0.48) or age (aOR for 45-59 vs <45 years, 1.16; 95% CI 0.87 to 1.54; adjusted p=0.48; aOR for ≥60 vs <45 years, 0.88; 95% CI 0.66 to 1.16; adjusted p=0.48). These patterns were similar when examining nirmatrelvir-ritonavir and molnupiravir separately. CONCLUSIONS: Our findings suggest that provider-level factors, such as the clinical experience of treating the patients with COVID-19, play an important role in the appropriate prescription of antiviral medications for COVID-19 in the primary care setting.

Machine Learning Detects Heterogeneous Effects of Medicaid Coverage on Depression.

In 2008, Oregon expanded its Medicaid program using a lottery, creating a rare opportunity to study the effects of Medicaid coverage using a randomized controlled design (Oregon Health Insurance Experiment). Analysis showed that Medicaid coverage lowered the risk of depression. However, this effect may vary between individuals, and the identification of individuals likely to benefit the most has the potential to improve the effectiveness and efficiency of the Medicaid program. By applying the machine learning causal forest to data from this experiment, we found substantial heterogeneity in the effect of Medicaid coverage on depression; individuals with high predicted benefit were older and had more physical or mental health conditions at baseline. Expanding coverage to individuals with high predicted benefit generated greater reduction in depression prevalence than expanding to all eligible individuals (21.5 vs. 8.8 percentage point reduction; adjusted difference [95%CI], +12.7 [+4.6,+20.8]; P=0.003), at substantially lower cost per case prevented ($16,627 vs. $36,048; adjusted difference [95%CI], -$18,598 [-$156,953,-$3,120]; P=0.04). Medicaid coverage reduces depression substantially more in a subset of the population than others, in ways that are predictable in advance. Targeting coverage on those most likely to benefit could improve the effectiveness and efficiency of insurance expansion.

Changes in surgical mortality during COVID-19 pandemic by patients' race, ethnicity and socioeconomic status among US older adults: a quasi-experimental event study model.

OBJECTIVES: To examine changes in the 30-day surgical mortality rate after common surgical procedures during the COVID-19 pandemic and investigate whether its impact varies by urgency of surgery or patient race, ethnicity and socioeconomic status. DESIGN: We used a quasi-experimental event study design to examine the effect of the COVID-19 pandemic on surgical mortality rate, using patients who received the same procedure in the prepandemic years (2016-2019) as the control, adjusting for patient characteristics and hospital fixed effects (effectively comparing patients treated at the same hospital). We conducted stratified analyses by procedure urgency, patient race, ethnicity and socioeconomic status (dual-Medicaid status and median household income). SETTING: Acute care hospitals in the USA. PARTICIPANTS: Medicare fee-for-service beneficiaries aged 65-99 years who underwent one of 14 common surgical procedures from 1 January 2016 to 31 December 2020. MAIN OUTCOME MEASURES: 30-day postoperative mortality rate. RESULTS: Our sample included 3 620 689 patients. Surgical mortality was higher during the pandemic, with peak mortality observed in April 2020 (adjusted risk difference (aRD) +0.95 percentage points (pp); 95% CI +0.76 to +1.26 pp; p<0.001) and mortality remained elevated through 2020. The effect of the pandemic on mortality was larger for non-elective (vs elective) procedures (April 2020: aRD +0.44 pp (+0.16 to +0.72 pp); p=0.002 for elective; aRD +1.65 pp (+1.00, +2.30 pp); p<0.001 for non-elective). We found no evidence that the pandemic mortality varied by patients' race and ethnicity (p for interaction=0.29), or socioeconomic status (p for interaction=0.49). CONCLUSIONS: 30-day surgical mortality during the COVID-19 pandemic peaked in April 2020 and remained elevated until the end of the year. The influence of the pandemic on surgical mortality did not vary by patient race and ethnicity or socioeconomic status, indicating that once patients were able to access care and undergo surgery, surgical mortality was similar across groups.

Comparison of Effectiveness Among Different Sodium-Glucose Cotransoporter-2 Inhibitors According to Underlying Conditions: A Network Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: To investigate the individual profile of each SGLT2 (sodium-glucose cotransoporter-2) inhibitor in patients with different backgrounds. METHODS AND RESULTS: This study included 21 placebo-controlled randomized controlled trials with a total of 96 196 participants, investigating empagliflozin, ertugliflozin, dapagliflozin, canagliflozin, and sotagliflozin. The primary efficacy end point was the composite of cardiovascular death and hospitalizations for heart failure. The secondary efficacy end points were all-cause death, cardiovascular death, hospitalizations for heart failure, kidney disease progression, and acute kidney injury. We conducted subgroup analyses based on the underlying comorbidities, including diabetes and chronic kidney disease. Safety end points were also assessed among SGLT2 inhibitors in the overall cohort. In the overall cohort, there were no significant differences in the primary efficacy outcome among the SGLT2 inhibitors, while empagliflozin (hazard ratio [HR], 0.70 [95% CI, 0.53-0.92]) and dapagliflozin (HR, 0.73 [95% CI, 0.56-0.96]) were associated with lower risk of acute kidney injury than sotagliflozin. The presence or absence of diabetes did not alter the results. In patients with chronic kidney disease, there were no differences in the efficacy outcomes among SGLT2 inhibitors, while in patients without chronic kidney disease, empagliflozin was associated with lower risk of the primary outcome compared with ertugliflozin (HR, 0.77 [95% CI, 0.60-0.98]). For safety outcomes, no significant differences were observed in amputation, urinary tract infection, genital infection, hypoglycemia, and diabetic ketoacidosis. CONCLUSIONS: The differences in reducing cardiovascular and kidney outcomes as well as safety profiles across SGLT2 inhibitors were not consistently significant, although empagliflozin might be preferred in patients without chronic kidney disease. Further investigations are needed to better understand the mechanism and clinical effectiveness of each SGLT2 inhibitor in certain populations.

Early-Stage Chronic Kidney Disease and Related Health Care Spending.

Importance: The global burden of chronic kidney disease (CKD) is substantial and potentially leads to higher health care resource use. Objective: To examine the association between early-stage CKD and health care spending and its changes over time in the general population. Design, Setting, and Participants: Cohort study using nationwide health checkup and medical claims data in Japan. Participants included individuals aged 30 to 70 years with estimated glomerular filtration rates (eGFR) of 30 mL/min/1.73 m2 or greater at the baseline screening in 2014. Data analyses were conducted from April 2021 to October 2023. Exposure: The CKD stages at baseline, defined by the eGFR and proteinuria, were as follows: eGFR of 60 mL/min/1.73 m2 or greater without proteinuria, eGFR of 60 mL/min/1.73 m2 or greater with proteinuria, eGFR of 30 to 59 mL/min/1.73 m2 without proteinuria, and eGFR of 30 to 59 mL/min/1.73 m2 with proteinuria. Main Outcome and Measures: The primary outcome was excess health care spending, defined as the absolute difference in health care spending according to the baseline CKD stages (reference group: eGFR ≥60 mL/min/1.73 m2 without proteinuria) in the baseline year (2014) and in the following 5 years (2015 to 2019). Results: Of the 79 988 participants who underwent a health checkup (mean [SD] age, 47.0 [9.4] years; 22 027 [27.5%] female), 2899 (3.6%) had an eGFR of 60 mL/min/1.73 m2 or greater with proteinuria, 1116 (1.4%) had an eGFR of 30 to 59 mL/min/1.73 m2 without proteinuria, and 253 (0.3%) had an eGFR of 30 to 59 mL/min/1.73 m2 with proteinuria. At baseline, the presence of proteinuria and an eGFR less than 60 mL/min/1.73 m2 were associated with greater excess health care spending (adjusted difference, $178; 99% CI, $6-$350 for proteinuria; $608; 99% CI, $233-$983 for an eGFR of 30-59 mL/min/1.73 m2; and $1254; 99% CI, $134-$2373 for their combination). The study consistently found excess health care spending over the following 5 examined years. Conclusions and Relevance: In this cohort study of nationwide health checkup and medical claims data in Japan, early-stage CKD was associated with excess health care spending over the 5 examined years, and the association was more pronounced with a more advanced disease stage.

Cardiac Reoperation or Transcatheter Mitral Valve Replacement for Patients With Failed Mitral Prostheses.

BACKGROUND: Evidence is limited regarding patient outcomes comparing redo surgical mitral valve replacement (redo SMVR) vs transcatheter mitral valve replacement (TMVR) for failed prostheses. OBJECTIVES: The goal of this study was to compare the outcomes of redo SMVR vs TMVR in patients with failed prostheses, as well as evaluate the association between case volume and outcomes. METHODS: Medicare beneficiaries aged ≥65 years who underwent redo SMVR or TMVR for failed mitral prostheses between 2016 and 2020 were included. The primary endpoint was mid-term (up to 3 years) major adverse cardiovascular events (MACE), including all-cause death, heart failure rehospitalization, stroke, or reintervention. Propensity score-matched analysis was used. RESULTS: A total of 4,293 patients were included (redo SMVR: 64%; TMVR: 36%). TMVR recipients were older, with a higher comorbidity burden. In matched cohort (n = 1,317 in each group), mid-term risk of MACE was similar (adjusted HR: 0.92; 95% CI: 0.80-1.04; P = 0.2). However, landmark analysis revealed a lower risk of MACE with TMVR in the first 6 months (adjusted HR: 0.75; 95% CI: 0.63-0.88; P < 0.001) albeit with a higher risk beyond 6 months (adjusted HR: 1.28; 95% CI: 1.04-1.58; P = 0.02). Increasing procedural volume was associated with decreased risk of mid-term MACE after redo SMVR (P = 0.001) but not after TMVR (P = 0.3). CONCLUSIONS: In this large cohort of Medicare beneficiaries with failed mitral prostheses, outcomes were similar between redo SMVR and TMVR at 3 years, with TMVR showing a lower initial risk but a higher risk of MACE after 6 months. These findings highlight the importance of striking a balance between surgical risk, anticipated longevity, and hospital expertise when selecting interventions.

Changes in Site of Death Among Older Adults Without a COVID-19 Diagnosis During the COVID-19 Pandemic.

BACKGROUND: Understanding how the coronavirus disease 2019 (COVID-19) pandemic affected site of death-an important patient-centered outcome related to end-of-life care-would inform healthcare system resiliency in future public health emergencies. OBJECTIVE: To evaluate the changes in site of death during the COVID-19 pandemic among older adults without a COVID-19 diagnosis. DESIGN: Using a quasi-experimental difference-in-differences method, we estimated net changes in site of death during the pandemic period (March-December 2020) from the pre-pandemic period (January-February 2020), using data on the same months in prior years (2016-2019) as the control. PARTICIPANTS: A 20% sample of Medicare Fee-for-Service beneficiaries aged 66 years and older who died in 2016-2020. We excluded beneficiaries with a hospital diagnosis of COVID-19. MAIN MEASURES: We assessed each of the following sites of death separately: (1) home or community; (2) acute care hospital; and (3) nursing home. KEY RESULTS: We included 1,133,273 beneficiaries without a hospital diagnosis of COVID-19. We found that the proportion of Medicare beneficiaries who died at home or in the community setting increased (difference-in-differences [DID] estimate, + 3.1 percentage points [pp]; 95% CI, + 2.6 to + 3.6 pp; P < 0.001) and the proportion of beneficiaries who died (without COVID-19 diagnosis) in an acute care hospital decreased (- 0.8 pp; 95% CI, - 1.2 to - 0.4 pp; P < 0.001) during the pandemic. We found no evidence that the proportion of deaths in nursing homes changed during the pandemic. CONCLUSIONS: Using national data on older adults without a COVID-19 diagnosis, we found that site of death shifted toward home or community settings during the COVID-19 pandemic. Our findings may inform clinicians and policymakers in supporting end-of-life care during future public health emergencies.

Association between patient-surgeon gender concordance and mortality after surgery in the United States: retrospective observational study.

OBJECTIVE: To determine whether patient-surgeon gender concordance is associated with mortality of patients after surgery in the United States. DESIGN: Retrospective observational study. SETTING: Acute care hospitals in the US. PARTICIPANTS: 100% of Medicare fee-for-service beneficiaries aged 65-99 years who had one of 14 major elective or non-elective (emergent or urgent) surgeries in 2016-19. MAIN OUTCOME MEASURES: Mortality after surgery, defined as death within 30 days of the operation. Adjustments were made for patient and surgeon characteristics and hospital fixed effects (effectively comparing patients within the same hospital). RESULTS: Among 2 902 756 patients who had surgery, 1 287 845 (44.4%) had operations done by surgeons of the same gender (1 201 712 (41.4%) male patient and male surgeon, 86 133 (3.0%) female patient and female surgeon) and 1 614 911 (55.6%) were by surgeons of different gender (52 944 (1.8%) male patient and female surgeon, 1 561 967 (53.8%) female patient and male surgeon). Adjusted 30 day mortality after surgery was 2.0% for male patient-male surgeon dyads, 1.7% for male patient-female surgeon dyads, 1.5% for female patient-male surgeon dyads, and 1.3% for female patient-female surgeon dyads. Patient-surgeon gender concordance was associated with a slightly lower mortality for female patients (adjusted risk difference -0.2 percentage point (95% confidence interval -0.3 to -0.1); P<0.001), but a higher mortality for male patients (0.3 (0.2 to 0.5); P<0.001) for elective procedures, although the difference was small and not clinically meaningful. No evidence suggests that operative mortality differed by patient-surgeon gender concordance for non-elective procedures. CONCLUSIONS: Post-operative mortality rates were similar (ie, the difference was small and not clinically meaningful) among the four types of patient-surgeon gender dyads.

The Accuracy and Potential Racial and Ethnic Biases of GPT-4 in the Diagnosis and Triage of Health Conditions: Evaluation Study.

BACKGROUND: Whether GPT-4, the conversational artificial intelligence, can accurately diagnose and triage health conditions and whether it presents racial and ethnic biases in its decisions remain unclear. OBJECTIVE: We aim to assess the accuracy of GPT-4 in the diagnosis and triage of health conditions and whether its performance varies by patient race and ethnicity. METHODS: We compared the performance of GPT-4 and physicians, using 45 typical clinical vignettes, each with a correct diagnosis and triage level, in February and March 2023. For each of the 45 clinical vignettes, GPT-4 and 3 board-certified physicians provided the most likely primary diagnosis and triage level (emergency, nonemergency, or self-care). Independent reviewers evaluated the diagnoses as "correct" or "incorrect." Physician diagnosis was defined as the consensus of the 3 physicians. We evaluated whether the performance of GPT-4 varies by patient race and ethnicity, by adding the information on patient race and ethnicity to the clinical vignettes. RESULTS: The accuracy of diagnosis was comparable between GPT-4 and physicians (the percentage of correct diagnosis was 97.8% (44/45; 95% CI 88.2%-99.9%) for GPT-4 and 91.1% (41/45; 95% CI 78.8%-97.5%) for physicians; P=.38). GPT-4 provided appropriate reasoning for 97.8% (44/45) of the vignettes. The appropriateness of triage was comparable between GPT-4 and physicians (GPT-4: 30/45, 66.7%; 95% CI 51.0%-80.0%; physicians: 30/45, 66.7%; 95% CI 51.0%-80.0%; P=.99). The performance of GPT-4 in diagnosing health conditions did not vary among different races and ethnicities (Black, White, Asian, and Hispanic), with an accuracy of 100% (95% CI 78.2%-100%). P values, compared to the GPT-4 output without incorporating race and ethnicity information, were all .99. The accuracy of triage was not significantly different even if patients' race and ethnicity information was added. The accuracy of triage was 62.2% (95% CI 46.5%-76.2%; P=.50) for Black patients; 66.7% (95% CI 51.0%-80.0%; P=.99) for White patients; 66.7% (95% CI 51.0%-80.0%; P=.99) for Asian patients, and 62.2% (95% CI 46.5%-76.2%; P=.69) for Hispanic patients. P values were calculated by comparing the outputs with and without conditioning on race and ethnicity. CONCLUSIONS: GPT-4's ability to diagnose and triage typical clinical vignettes was comparable to that of board-certified physicians. The performance of GPT-4 did not vary by patient race and ethnicity. These findings should be informative for health systems looking to introduce conversational artificial intelligence to improve the efficiency of patient diagnosis and triage.

Effect of age-based left-digit bias on stroke diagnosis: Regression discontinuity design.

BACKGROUND: Little is known about how left-digit bias- where humans tend to discretely categorize their decisions based on the left-most digit of the continuous variables-based on patients' age affects the initial diagnosis of stroke patients. The aim of this study is to examine whether there is a discontinuous change in the ordering of imaging tests for stroke at the age threshold of 40 years old, which is indicative of left-digit bias, and whether the effect varies by patient sex. METHODS: We conducted a cohort study by regression discontinuity design (RDD). We analyzed the claims database from a nationwide working-age health insurance plan in Japan. Patients who had after-hours hospital visits from January 2014 through December 2019 were included in our analysis. The exposure is patients' age, and the primary outcome was physicians' ordering imaging tests (CT or MRI) to diagnose stroke during the index visit. RESULTS: Of 293,390 total visits, 48,598 visits within data-driven optimal bandwidths of 6.0 years from the cut-off of 40 years were included for the RDD analysis (mean age 40.8 years [standard deviation 3.4], female 50.5%). The baseline probability of receiving imaging tests for stroke diagnosis was 0.9%. Physicians had a higher likelihood of ordering imaging tests when patients' age was above 40 years compared with when patients' age was just below 40 years (adjusted difference, +0.51 percentage points [pp], 95%CI, +0.13 to +1.07 pp; P = 0.01). We found a significant discontinuous change in the ordering of imaging tests for stroke at 40 years for male patients (+0.84 pp, 95%CI, +0.24 to +1.69 pp; P = 0.009) but not for female patients. CONCLUSIONS: Physicians have a cognitive bias in estimating stroke risk and, consistent with a left-digit bias, treat male patients aged 40 and just below differently. This pattern was observed only among male patients.

Effect of no cost sharing for paediatric care on healthcare usage by household income levels: regression discontinuity design.

OBJECTIVES: To investigate the impact of no cost sharing on paediatric care on usage and health outcomes, and whether the effect varies by household income levels. DESIGN: Regression discontinuity design. SETTING: Nationwide medical claims database in Japan. PARTICIPANTS: Children aged younger than 20 years from April 2018 to March 2022. EXPOSURE: Co-insurance rate that increases sharply from 0% to 30% at a certain age threshold (the threshold age varies between 6 and 20 years depending on region). PRIMARY OUTCOME MEASURES: The outpatient care usage (outpatient visit days and healthcare spending for outpatient care) and inpatient care (experience of any hospitalisation and healthcare spending for inpatient care). RESULTS: Of 244 549 children, 49 556 participants were in the bandwidth and thus included in our analyses. Results from the regression discontinuity analysis indicate that no cost sharing was associated with a significant increase in the number of outpatient visit days (+5.26 days; 95% CI, +4.89 to +5.82; p<0.01; estimated arc price elasticity, -0.45) and in outpatient healthcare spending (+US$369; 95% CI, +US$344 to +US$406; p<0.01; arc price elasticity, -0.55). We found no evidence that no cost sharing was associated with changes in inpatient care usage. Notably, the effect of no cost-sharing policy on outpatient healthcare usage was larger among children from high-income households (visit days +5.96 days; 95% CI, +4.88 to +7.64, spending +US$511; 95% CI, +US$440 to +US$627) compared with children from low-income households (visit days +2.64 days; 95% CI, +1.54 to +4.23, spending +US$154; 95% CI, +US$80 to +US$249). CONCLUSIONS: No cost sharing for paediatric care was associated with a greater usage of outpatient care services, but did not affect inpatient care usage. The study found that this effect was more pronounced among children from high-income households, indicating that the no cost sharing disproportionately benefits high-income households and may contribute to larger disparities.

Antibiotic Prescription for Outpatients With COVID-19 in Primary Care Settings in Japan.

This cross-sectional study assesses the characteristics of patients and physicians associated with antibiotic prescription for COVID-19.

Association between physicians' geriatric training and patterns of end-of-life care delivered to persons with dementia.

BACKGROUND: Geriatric training is designed to prepare physicians to meet the complex needs of older adults, including persons with dementia at the end-of-life (EOL) stage. We sought to compare patterns of EOL care delivered to persons with dementia between physicians with versus without geriatric training. METHODS: We conducted a cross-sectional study of a 20% random sample of fee-for-service Medicare beneficiaries with dementia who died in 2016-2018 (n = 99,631). We attributed beneficiaries to a physician who had the largest number of primary care visits during the last 6 months of life and determined whether the physician was trained in geriatrics. Our outcome measures included: (i) advance care planning (ACP) and palliative care (e.g., ACP, hospice enrollment in the last 90 days of life), and (ii) high-intensity EOL care (e.g., emergency department visits or hospital admissions in the last 30 days of life). RESULTS: Beneficiaries with dementia under the care of physicians with geriatric training had a higher proportion of ACP (adjusted proportion, 15.8% vs. 13.0%; p < 0.001 after accounting for multiple comparisons), palliative care counseling (22.4% vs. 20.9%; p = 0.01), and hospice enrollment (63.7% vs. 60.6%; p < 0.001). Geriatric training was also associated with a lower proportion of emergency department visits (55.1% vs. 59.1%; p < 0.001), hospital admissions (48.8% vs. 52.3%; p < 0.001), ICU admissions (24.9% vs. 27.4%; p < 0.001), use of mechanical ventilation (11.2% vs. 13.0%; p < 0.001), and use of cardiopulmonary resuscitation (2.1% vs. 2.4%; p = 0.03) in the last 30 days of life. There was no evidence that the placement of feeding tubes differed between the two groups. CONCLUSIONS: Physicians' geriatric training was associated with the receipt of more ACP and palliative care and less intensive EOL care among persons with dementia. Provision of geriatric training for physicians may have the potential to improve the quality of EOL care delivered to persons with dementia.

Timing and setting of billed advance care planning among Medicare decedents in 2017-2019.

BACKGROUND: The Centers for Medicare & Medicaid Services (CMS) began to reimburse clinicians for advance care planning (ACP) discussions, effective January 1, 2016. We sought to characterize the timing and setting of first-billed ACP discussions among Medicare decedents to inform future research on ACP billing codes. METHODS: Using a random 20% sample of Medicare fee-for-service beneficiaries aged 66 years and older who died in 2017-2019, we described the timing (relative to death) and setting (inpatient, nursing home, office, or outpatient with or without Medicare Annual Wellness Visit [AWV], home or community, or elsewhere) of the first-billed ACP discussion for each beneficiary. RESULTS: Our study included 695,985 decedents (mean [SD] years of age, 83.2 [8.8]; 54.2% female); the proportion of decedents who had at least one billed ACP discussion increased from 9.7% in 2017 to 21.9% in 2019. We found that the proportion of first-billed ACP discussions held during the last month of life decreased from 37.0% in 2017 to 26.2% in 2019, while the proportion of first-billed ACP discussions held more than 12 months before death increased from 11.1% in 2017 to 35.2% in 2019. We also found that the proportion of first-billed ACP discussions held in the office or outpatient setting along with AWV increased over time (from 10.7% in 2017 to 14.1% in 2019), while the proportion held in the inpatient setting decreased (from 41.7% in 2017 to 38.0% in 2019). CONCLUSIONS: We found that with increasing exposure to the CMS policy change, uptake of the ACP billing code has increased; first-billed ACP discussions are occurring sooner before the end-of-life stage and are more likely to occur with AWV. Future studies should evaluate changes in ACP practice patterns, rather than only an increasing uptake in ACP billing codes, following the policy implementation.

Comparison of Hospital Outcomes for Patients Treated by Allopathic Versus Osteopathic Hospitalists : An Observational Study.

BACKGROUND: The United States has 2 types of degree programs that educate physicians: allopathic and osteopathic medical schools. OBJECTIVE: To determine whether quality and costs of care differ between hospitalized Medicare patients treated by allopathic or osteopathic physicians. DESIGN: Retrospective observational study. SETTING: Medicare claims data. PATIENTS: 20% random sample of Medicare fee-for-service beneficiaries hospitalized with a medical condition during 2016 to 2019 and treated by hospitalists. MEASUREMENTS: The primary outcome was 30-day patient mortality. The secondary outcomes were 30-day readmission, length of stay (LOS), and health care spending (Part B spending). Multivariable regression models adjusted for patient and physician characteristics and their hospital-level averages (to effectively estimate differences within hospitals) were estimated. RESULTS: Of 329 510 Medicare admissions, 253 670 (77.0%) and 75 840 (23.0%) received care from allopathic and osteopathic physicians, respectively. The results can rule out important differences in quality and costs of care between allopathic versus osteopathic physicians for patient mortality (adjusted mortality, 9.4% for allopathic physicians vs. 9.5% [reference] for osteopathic hospitalists; average marginal effect [AME], -0.1 percentage point [95% CI, -0.4 to 0.1 percentage point]; P = 0.36), readmission (15.7% vs. 15.6%; AME, 0.1 percentage point [CI, -0.4 to 0.3 percentage point; P = 0.72), LOS (4.5 vs. 4.5 days; adjusted difference, -0.001 day [CI, -0.04 to 0.04 day]; P = 0.96), and health care spending ($1004 vs. $1003; adjusted difference, $1 [CI, -$8 to $10]; P = 0.85). LIMITATION: Data were limited to elderly Medicare patients hospitalized with medical conditions. CONCLUSION: The quality and costs of care were similar between allopathic and osteopathic hospitalists when they cared for elderly patients and worked as the principal physician in a team of health care professionals that often included other allopathic and osteopathic physicians. PRIMARY FUNDING SOURCE: National Institutes of Health/National Institute on Aging.

Machine-learning-based high-benefit approach versus conventional high-risk approach in blood pressure management.

BACKGROUND: In medicine, clinicians treat individuals under an implicit assumption that high-risk patients would benefit most from the treatment ('high-risk approach'). However, treating individuals with the highest estimated benefit using a novel machine-learning method ('high-benefit approach') may improve population health outcomes. METHODS: This study included 10 672 participants who were randomized to systolic blood pressure (SBP) target of either <120 mmHg (intensive treatment) or <140 mmHg (standard treatment) from two randomized controlled trials (Systolic Blood Pressure Intervention Trial, and Action to Control Cardiovascular Risk in Diabetes Blood Pressure). We applied the machine-learning causal forest to develop a prediction model of individualized treatment effect (ITE) of intensive SBP control on the reduction in cardiovascular outcomes at 3 years. We then compared the performance of high-benefit approach (treating individuals with ITE >0) versus the high-risk approach (treating individuals with SBP ≥130 mmHg). Using transportability formula, we also estimated the effect of these approaches among 14 575 US adults from National Health and Nutrition Examination Surveys (NHANES) 1999-2018. RESULTS: We found that 78.9% of individuals with SBP ≥130 mmHg benefited from the intensive SBP control. The high-benefit approach outperformed the high-risk approach [average treatment effect (95% CI), +9.36 (8.33-10.44) vs +1.65 (0.36-2.84) percentage point; difference between these two approaches, +7.71 (6.79-8.67) percentage points, P-value <0.001]. The results were consistent when we transported the results to the NHANES data. CONCLUSIONS: The machine-learning-based high-benefit approach outperformed the high-risk approach with a larger treatment effect. These findings indicate that the high-benefit approach has the potential to maximize the effectiveness of treatment rather than the conventional high-risk approach, which needs to be validated in future research.

Association of Daily Step Patterns With Mortality in US Adults.

Importance: Previous studies have shown that individuals who regularly walk, particularly 8000 daily steps or more, experience lower mortality. However, little is known about the health benefits of walking intensively only a few days a week. Objective: To evaluate the dose-response association between the number of days an individual takes 8000 steps or more and mortality among US adults. Design, Setting, and Participants: This cohort study evaluated a representative sample of participants aged 20 years or older in the National Health and Nutrition Examination Surveys 2005-2006 who wore an accelerometer for 1 week and their mortality data through December 31, 2019. Data were analyzed from April 1, 2022, to January 31, 2023. Exposures: Participants were grouped by the number of days per week they took 8000 steps or more (0 days, 1-2 days, and 3-7 days). Main Outcomes and Measures: Multivariable ordinary least squares regression models were used to estimate adjusted risk differences (aRDs) for all-cause and cardiovascular mortality during the 10-year follow-up, adjusting for potential confounders (eg, age, sex, race and ethnicity, insurance status, marital status, smoking, comorbidities, and average daily step counts). Results: Among 3101 participants (mean [SD] age, 50.5 [18.4] years; 1583 [51.0%] women and 1518 [49.0%] men; 666 [21.5%] Black, 734 [23.7%] Hispanic, 1579 [50.9%] White, and 122 [3.9%] other race and ethnicity), 632 (20.4%) did not take 8000 steps or more any day of the week, 532 (17.2%) took 8000 steps or more 1 to 2 days per week, and 1937 (62.5%) took 8000 steps or more 3 to 7 days per week. Over the 10-year follow-up, all-cause and cardiovascular deaths occurred in 439 (14.2%) and 148 (5.3%) participants, respectively. Compared with participants who walked 8000 steps or more 0 days per week, all-cause mortality risk was lower among those who took 8000 steps or more 1 to 2 days per week (aRD, -14.9%; 95% CI -18.8% to -10.9%) and 3 to 7 days per week (aRD, -16.5%; 95% CI, -20.4% to -12.5%). The dose-response association for both all-cause and cardiovascular mortality risk was curvilinear; the protective association plateaued at 3 days per week. Different thresholds for the number of daily steps between 6000 and 10 000 yielded similar results. Conclusions and Relevance: In this cohort study of US adults, the number of days per week taking 8000 steps or more was associated with a lower risk of all-cause and cardiovascular mortality in a curvilinear fashion. These findings suggest that individuals may receive substantial health benefits by walking just a couple days a week.