Validation of Claims-Based Frailty Index for Identifying Moderate-to-Severe Dementia in Medicare Beneficiaries.

OBJECTIVE: Previous research using the National Health and Aging Trends Study showed that a claims-based frailty index (CFI) could be useful for identifying moderate-to-severe dementia in Medicare claims data. This study aims to validate the findings in an independent cohort. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: The study included 658 fee-for-service beneficiaries with dementia who participated in the 2016-2020 Medicare Current Beneficiary Survey in the community-dwelling. METHODS: We operationalized the Functional Assessment Staging Test (FAST) scale (range: 1-7, stages 5-7 indicate moderate-to-severe dementia) using survey information. CFI (range: 0-1, higher scores indicate greater frailty) was calculated using Medicare claims 12 months before the participants' interview date. Using the previously proposed cut point of 0.280, we calculated sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for identifying moderate-to-severe dementia. Survey procedures were used to account for survey design and weighted to reflect national estimates. RESULTS: The population had a mean age (SD) of 80.7 (8.9) years, 58.5% female, and 101 beneficiaries (14.8%) had moderate-to-severe dementia. The CFI cut point of 0.280 demonstrated sensitivity 0.49 (95% CI, 0.38-0.59), specificity 0.80 (0.77-0.84), PPV 0.30 (0.23-0.38), and NPV 0.90 (0.87-0.93). Compared with those with a CFI <0.280, beneficiaries with a CFI ≥0.280 had an elevated risk of mortality (2.9% vs 4.1%) over 1 year. CONCLUSIONS AND IMPLICATIONS: These results confirm our previous findings that CFI among beneficiaries with a dementia diagnosis is a useful measure of moderate-to-severe dementia for Medicare claims data.

Extracts of Phlomoides umbrosa Turczaninow alleviate allergic airway inflammation in lipopolysaccharide-stimulated RAW 264.7 cells and ovalbumin-induced hyper-responsiveness mouse model.

Phlomoides umbrosa Turczaninow (PU), a traditional Korean medicinal herb, exhibits osteogenic and anti-inflammatory effects. This research explored the effect of PU extracts on hyperimmune responses within the respiratory tract using lipopolysaccharide-stimulated RAW 264.7 cells and an ovalbumin-induced hyper-responsiveness model. The inflammatory cytokines, protein expression linked to airway inflammation, antioxidant enzyme activity, histopathological observation, and expectorant activity were measured. The results revealed that PU treatment led to a concentration-dependent reduction in Th2 cytokines and the expression of nuclear factor (NF)-κB, phosphatase-tensin homolog, mitogen-activated protein kinase (MAPK), and inducible nitric oxide synthase (iNOS). Simultaneously, antioxidant enzyme activity increased. Furthermore, PU exhibited substantial enhancements in lung tissue condition and expectorant activity relative to the allergic rhinitis-induced group. These findings indicate the potential of PU to mitigate airway inflammation and excessive mucus production by suppressing NF-κB, MAPK, and iNOS pathways. Consequently, PU emerges as a promising anti-inflammatory agent for respiratory tract applications. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-024-01521-3.

Highly conductive, stretchable, and biocompatible graphene oxide biocomposite hydrogel for advanced tissue engineering.

The importance of hydrogels in tissue engineering cannot be overemphasized due to their resemblance to the native extracellular matrix (ECM). However, natural hydrogels with satisfactory biocompatibility exhibit poor mechanical behavior, which hampers their application in stress-bearing soft tissue engineering. Here, we describe the fabrication of a double methacrylated gelatin bioink covalently linked to graphene oxide (GO) via a zero-length crosslinker, digitally light-processed (DLP) printable into 3D complex structures with high fidelity. The resultant natural hydrogel (GelGOMA) exhibits a conductivity of 15.0 S m-1 as a result of the delocalization of the π-orbital from the covalently linked GO. Furthermore, the hydrogel shows a compressive strength of 1.6 MPa, and a 2.0 mm thick GelGOMA can withstand a 1.0 kg ms­1 momentum. The printability and mechanical properties of GelGOMA were demonstrated by printing a fish heart with a functional fluid pumping mechanism and tricuspid valves. Its biocompatibility, electroconductivity, and physiological relevance enhanced the proliferation and differentiation of myoblasts and neuroblasts and the contraction of hiPSC-derived cardiomyocytes. GelGOMA demonstrates the potential for the tissue engineering of functional hearts and wearable electronic devices. .

Efficient Deep-Blue Light-Emitting Diodes Through Decoupling of Colloidal Perovskite Quantum Dots.

Metal halide perovskite light-emitting diodes (PeLEDs) have exceptional color purity but designs that emit deep-blue color with high efficiency have not been fully achieved and become more difficult in the thin film of confined perovskite colloidal quantum dots (PeQDs) due to particle interaction. Here it is demonstrated that electronic coupling and energy transfer in PeQDs induce redshift in the emission by PeQD film, and consequently hinder deep-blue emission. To achieve deep-blue emission by avoiding electronic coupling and energy transfer, a QD-in-organic solid solution is introduced to physically separate the QDs in the film. This physical separation of QDs reduces the interaction between them yielding a blueshift of ≈7 nm in the emission spectrum. Moreover, using a hole-transporting organic molecule with a deep-lying highest occupied molecular orbital (≈6.0 eV) as the organic matrix, the formation of exciplex emission is suppressed. As a result, an unprecedently high maximum external quantum efficiency of 6.2% at 462 nm from QD-in-organic solid solution film in PeLEDs is achieved, which satisfies the deep-blue color coordinates of CIEy < 0.06. This work suggests an important material strategy to deepen blue emission without reducing the particle size to <≈4 nm.

Enhancing procedural decision making with cone beam CT in renal artery embolization.

Cone-beam computed tomography (CBCT) has proven to be a safe and effective adjunctive imaging tool for interventional radiology. Nevertheless, limited studies have examined the application of CBCT in renal artery embolization (RAE). The objective of this study is to evaluate the role of CBCT in intra-procedural decision-making for RAE. This multicenter retrospective study included 40 consecutive patients (age: 55.9 ± 16.5 years; male, 55%) who underwent CBCT during RAE from January 2019 to January 2023. The additional information provided by CBCT was classified into Category 1 (no additional information), Category 2 (more information without changing the treatment plan), and Category 3 (valuable information that led to a change in the treatment plan). CBCT did not add unique information for four patients (10%) classified as Category 1. CBCT clarified ambiguous angiographic findings and confirmed the existing treatment plan for 19 patients (47.5%) graded as Category 2; complex vascular anatomy was explained (n = 13), and a correlation between vascular territory and target lesion was established (n = 6). CBCT offered valuable information that was not visible on digital subtraction angiography and changed the treatment plan for 17 patients categorized as Category 3; a mismatch between the vascular territory and the target lesion led to the identification of alternative (n = 3) and additional feeders (n = 8); and the extent of embolization was reduced by using automatic feeder detection software (n = 6). CBCT is an efficient tool that aids in the decision-making process during the embolization procedure by providing supplementary imaging information. This additional information enables the confident identification of target vessels, facilitates superselective embolization, prevents non-target embolization, and helps locate missing feeders.

Fam49b dampens TCR signal strength to regulate survival of positively selected thymocytes and peripheral T cells.

The fate of developing T cells is determined by the strength of T cell receptor (TCR) signal they receive in the thymus. This process is finely regulated through the tuning of positive and negative regulators in thymocytes. The Family with sequence similarity 49 member B (Fam49b) protein is a newly discovered negative regulator of TCR signaling that has been shown to suppress Rac-1 activity in vitro in cultured T cell lines. However, the contribution of Fam49b to the thymic development of T cells is unknown. To investigate this important issue, we generated a novel mouse line deficient in Fam49b (Fam49b-KO). We observed that Fam49b-KO double positive (DP) thymocytes underwent excessive negative selection, whereas the positive selection stage was unaffected. Fam49b deficiency impaired the survival of single positive thymocytes and peripheral T cells. This altered development process resulted in significant reductions in CD4 and CD8 single-positive thymocytes as well as peripheral T cells. Interestingly, a large proportion of the TCRγδ+ and CD8αα+TCRαß+ gut intraepithelial T lymphocytes were absent in Fam49b-KO mice. Our results demonstrate that Fam49b dampens thymocytes TCR signaling in order to escape negative selection during development, uncovering the function of Fam49b as a critical regulator of the selection process to ensure normal thymocyte development and peripheral T cells survival.

Enhancing Prognostication and Treatment Response Evaluation in Primary CNS Lymphoma with 18F-FDG PET/CT.

BACKGROUND: The role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG-PET/CT) in the prognostication and response evaluation of primary central nervous system lymphoma (PCNSL) remains inadequately defined. METHODS: We conducted a retrospective analysis of 268 consecutive newly diagnosed patients with PCNSL between 2006 and 2020. Of these patients, 105 and 110 patients were included to evaluate the prognostic value of baseline and post-treatment 18F-FDG-PET/CT scans, respectively. Tumor uptake was considered positive when it exceeded that of the contralateral brain upon visual assessment. Quantitative analysis of baseline 18F-FDG-PET/CT included measurement of the maximal standardized uptake value (SUVmax), total metabolic tumor volume (TMTV), and total lesion glycolysis (TLG). RESULTS: The median age of the 268 patients was 62 years (range: 17-85), with 55% being male. The median progression-free survival (PFS) was 24.5 months (95% confidence interval [CI], 19.9-29.1), and the median overall survival (OS) was 34.5 months (95% CI, 22.9-46.1). The average SUVmax was 15.3 ± 5.7 and the mean TMTV and TLG were 12.6 ± 13.9 cm3 and 135.0 ± 152.7 g, respectively. Patients with a baseline TMTV ≥17.0 cm3 had significantly shorter OS (12.5 vs. 74.0 months, p=0.011). Post-treatment metabolic response by 18F-FDG-PET/CT significantly predicted PFS (median: 10.5 vs. 46.0 months, p=0.001) and OS (median: 21.0 vs. 62.0 months, p=0.002), whereas anatomic response by contrast-enhanced MRI showed no statistically significant differences in PFS (p=0.130) or OS (p=0.540). CONCLUSION: Baseline TMTV and post-treatment metabolic response, as assessed by 18F-FDG-PET/CT, are significant prognostic factors in patients with PCNSL.

Effects of body mass index on mortality in elderly patients with hip fractures.

Hip fractures remain a substantial health concern, particularly among elderly individuals with osteoporosis, leading to high global mortality rates. This study aimed to analyze the association between body mass index (BMI) and postoperative mortality in patients who underwent surgery for hip fractures. A total of 680 patients treated at a single institution between January 2018 and December 2022 were included. Factors such as age, BMI, sex, Charlson Comorbidity Index (CCI), preoperative hemoglobin levels, American Society of Anesthesiologists score, anesthesia method, duration of surgery, and time from injury to surgery were assessed. Underweight status, male sex, higher CCI, and general anesthesia were significantly associated with 1-year and in-hospital mortality. Notably, underweight individuals exhibited a higher risk of mortality than normal-weight individuals, and female patients had lower mortality rates. This study underscores the importance of considering BMI, along with other demographic and clinical factors, in predicting postoperative mortality among patients with hip fractures, aiding the development of tailored management strategies to improve outcomes and reduce complications in this vulnerable patient population.

Lateral Piezoelectricity of Alzheimer's Aß Aggregates.

Alzheimer's disease (AD) is the most frequent neurodegenerative disorder in the elderly aged over 65. The extracellular accumulation of beta-amyloid (Aß) aggregates in the brain is considered as the major event worsening the AD symptoms, but its underlying reason has remained unclear. Here the piezoelectric characteristics of Aß aggregates are revealed. The vector piezoresponse force microscopy (PFM) analysis results exhibit that Aß fibrils have spiraling piezoelectric domains along the length and a lateral piezoelectric constant of 44.1 pC N-1. Also, the continuous sideband Kelvin probe force microscopy (KPFM) images display that the increment of charge-induced surface potential on a single Aß fibril is allowed to reach above +1700 mV in response to applied forces. These findings shed light on the peculiar mechano-electrical surface properties of pathological Aß fibrils that exceed those of normal body components.

Diagnostic criteria for eosinophilic chronic rhinosinusitis: Comparative analysis and novel scoring system.

BACKGROUND: Accurate identification of eosinophilic chronic rhinosinusitis is essentialg because its treatment and prognosis substantially differ from other subtypes. METHODS: This retrospective observational study included 640 patients who underwent endoscopic sinus surgery for chronic rhinosinusitis in a single tertiary center from January 2021 to December 2022. Receiver operating characteristic curves were generated to compare accuracy, sensitivity, specificity of the novel scoring system, and previous diagnostic criteria (Japanese Epidemiological Survey of Refractory Eosinophilic Chronic Rhinosinusitis, European Forum for Research and Education in Allergy and Airway Diseases, European Position Paper on Rhinosinusitis and Nasal Polyps, and Sakuma et al.) for predicting eosinophilic chronic rhinosinusitis (ECRS) by tissue eosinophil count ≥70 per high power field. RESULTS: Patients were randomly divided into estimation (n = 430) and validation (n = 210) groups. The area under the receiver operating characteristic curve for the novel score was 0.753 (95% confidence interval [CI], 0.670-0.835) in the estimation group, 0.729 (0.629-0.830) in the validation group, and 0.661 (0.584-0.738) in the 20-fold cross-validation with the entire dataset. CONCLUSIONS: We propose a novel scoring system that incorporates three key parameters: "novel score = blood eosinophil (%) + total Lund-Mackay score of anterior ethmoid sinuses + 2 if nasal polyp present" greater than 7 can be reliably used for diagnosing ECRS. This system can facilitate decision-making processes regarding the administration of oral steroids and biologics targeting type 2 inflammation prior to surgical intervention.

Ferredoxin: A novel antimicrobial peptide derived from the black scraper (Thamnaconus modestus).

Ferredoxin (FDX) is a highly conserved iron-sulfur protein that participates in redox reactions and plays an important role as an electron transport protein in biological processes. However, its function in marine fish remains unclear. We identified two ferrodoxin proteins, FDX1 and FDX2, from black scraper (Thamnaconus modestus) to confirm their genetic structures and expression profiles and to investigate their antimicrobial activity properties by fabricating them with antimicrobial peptides based on sequences. The two TmFDXs mRNAs were most abundant in peripheral blood leukocytes of healthy T. modestus. After artificial infection with Vibrio anguillarum, a major pathogen of T. modestus, TmFDX1 mRNA was significantly upregulated in the gills, heart, intestines, kidneys, liver, and spleen, but was consistently downregulated in the brain. The expression levels of TmFDX2 mRNA were significantly upregulated in the heart, intestines, kidneys, liver, and spleen; however, no significant changes in expression were observed in the brain or gills. Based on the 2Fe-2S ferredoxin-type iron-sulfur-binding domain sequence, two peptides (pFDX1 and pFDX2) were synthesized. The bactericidal effect, biofilm formation inhibition, and gDNA-binding activity of these peptides were investigated. These findings highlight the potential as a natural peptide candidate for TmFDXs.

Male animal sterilization: history, current practices, and potential methods for replacing castration.

Sterilization and castration have been synonyms for thousands of years. Making an animal sterile meant to render them incapable of producing offspring. Castration or the physical removal of the testes was discovered to be the most simple but reliable method for managing reproduction and sexual behavior in the male. Today, there continues to be global utilization of castration in domestic animals. More than six hundred million pigs are castrated every year, and surgical removal of testes in dogs and cats is a routine practice in veterinary medicine. However, modern biological research has extended the meaning of sterilization to include methods that spare testis removal and involve a variety of options, from chemical castration and immunocastration to various methods of vasectomy. This review begins with the history of sterilization, showing a direct link between its practice in man and animals. Then, it traces the evolution of concepts for inducing sterility, where research has overlapped with basic studies of reproductive hormones and the discovery of testicular toxicants, some of which serve as sterilizing agents in rodent pests. Finally, the most recent efforts to use the immune system and gene editing to block hormonal stimulation of testis function are discussed. As we respond to the crisis of animal overpopulation and strive for better animal welfare, these novel methods provide optimism for replacing surgical castration in some species.

Mortality in patients receiving renal replacement therapy in South Korea.

Background: This study analyzed data from the end-stage renal disease patient registry collected by the Korean Society of Nephrology to explore trends in mortality among dialysis patients from 2001 to 2022. Methods: Mortality was analyzed in two ways: firstly, using the annual mortality rate; and secondly, by assessing survivability after a certain period of time since the initiation of dialysis. Additionally, we categorized the causes of death by disease group annually to observe how the proportions changed. Results: Since 2001, annual mortality for dialysis patients generally declined, except for a rise in 2020 and 2021 among hemodialysis patients. Overall mortality rates for all dialysis patients dropped from 74.2/1,000 person-years in 2001 to 42.3/1,000 person-years in 2022, with a more pronounced decrease in peritoneal dialysis. While survival probability over the 5 years following initiation of dialysis has shown a steady increase, short-term mortality from 2018 to 2020 affected by coronavirus disease 2019 (COVID-19) has shown a yearly increase by age group, with a greater effect in those aged 75 years and older. The leading causes of death for all dialysis patients have changed little, in the order of heart disease, infection, and vascular problems. Conclusion: While annual mortality and survival probability after dialysis initiation have generally improved in dialysis patients, there has been a temporary deterioration during the COVID-19 pandemic, most pronounced in the elderly.

SARS-CoV-2 Omicron XBB lineage spike structures, conformations, antigenicity, and receptor recognition.

A recombinant lineage of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron variant, named XBB, appeared in late 2022 and evolved descendants that successively swept local and global populations. XBB lineage members were noted for their improved immune evasion and transmissibility. Here, we determine cryoelectron microscopy (cryo-EM) structures of XBB.1.5, XBB.1.16, EG.5, and EG.5.1 spike (S) ectodomains to reveal reinforced 3-receptor binding domain (RBD)-down receptor-inaccessible closed states mediated by interprotomer RBD interactions previously observed in BA.1 and BA.2. Improved XBB.1.5 and XBB.1.16 RBD stability compensated for stability loss caused by early Omicron mutations, while the F456L substitution reduced EG.5 RBD stability. S1 subunit mutations had long-range impacts on conformation and epitope presentation in the S2 subunit. Our results reveal continued S protein evolution via simultaneous optimization of multiple parameters, including stability, receptor binding, and immune evasion, and the dramatic effects of relatively few residue substitutions in altering the S protein conformational landscape.

Epoxidation of perillyl alcohol by engineered bacterial cytochrome P450 BM3.

Perillyl alcohol (POH) is a secondary metabolite of plants. POH and its derivatives are known to be effective as an anticancer treatment. In this study, oxidative derivatives of POH, which are difficult to synthesize chemically, were synthesized using the engineered bacterial cytochrome P450 BM3 (CYP102A1) as a biocatalyst. The activity of wild-type (WT) CYP102A1 and 29 engineered enzymes toward POH was screened using a high-performance liquid chromatography. They produced one major product. Among them, the engineered CYP102A1 M601 mutant with seven mutations (R47L/F81I/F87V/E143G/L150F/L188Q/E267V) showed the highest conversion, 6.4-fold higher than the WT. Structure modeling using AlphFold2 and PyMoL suggests that mutations near the water channel may be responsible for the increased catalytic activity of the M601 mutant. The major product was identified as a POH-8,9-epoxide by gas chromatography-mass spectrometry and nuclear magnetic resonance analysis. The optimal temperature and pH for the product formation were 35 °C and pH 7.4, respectively. The kcat and Km of M601 were 540 min-1 and 2.77 mM, respectively. To improve POH-8,9-epoxide production, substrate concentration and reaction time were optimized. The optimal condition for POH-8,9-epoxide production by M601 was 5.0 mM POH, pH 7.4, 35 ℃, and 6 h reaction, which produced the highest concentration of 1.72 mM. Therefore, the biosynthesis of POH-8,9-epoxide using M601 as a biocatalyst is suggested to be an efficient and sustainable synthetic process that can be applied to chemical and pharmaceutical industries.

Cancer therapy-related cardiac dysfunction and the role of cardiovascular imaging: systemic review and opinion paper from the Working Group on Cardio-Oncology of the Korean Society of Cardiology.

Cardio-oncology is a critical field due to the escalating significance of cardiovascular toxicity as a side effect of anticancer treatments. Cancer therapy-related cardiac dysfunction (CTRCD) is a prevalent condition associated with cardiovascular toxicity, necessitating effective strategies for prediction, monitoring, management, and tracking. This comprehensive review examines the definition and risk stratification of CTRCD, explores monitoring approaches during anticancer therapy, and highlights specific cardiovascular toxicities linked to various cancer treatments. These include anthracyclines, HER2-targeted agents, vascular endothelial growth factor inhibitors, immune checkpoint inhibitors, chimeric antigen receptor T-cell therapies, and tumor-infiltrating lymphocytes therapies. Incorporating the Korean data, this review offers insights into the regional nuances in managing CTRCD. Using systematic follow-up incorporating cardiovascular imaging and biomarkers, a better understanding and management of CTRCD can be achieved, optimizing the cardiovascular health of both cancer patients and survivors.

Hypertrophic cardiomyopathy detection with artificial intelligence electrocardiography in international cohorts: an external validation study.

Aims: Recently, deep learning artificial intelligence (AI) models have been trained to detect cardiovascular conditions, including hypertrophic cardiomyopathy (HCM), from the 12-lead electrocardiogram (ECG). In this external validation study, we sought to assess the performance of an AI-ECG algorithm for detecting HCM in diverse international cohorts. Methods and results: A convolutional neural network-based AI-ECG algorithm was developed previously in a single-centre North American HCM cohort (Mayo Clinic). This algorithm was applied to the raw 12-lead ECG data of patients with HCM and non-HCM controls from three external cohorts (Bern, Switzerland; Oxford, UK; and Seoul, South Korea). The algorithm's ability to distinguish HCM vs. non-HCM status from the ECG alone was examined. A total of 773 patients with HCM and 3867 non-HCM controls were included across three sites in the merged external validation cohort. The HCM study sample comprised 54.6% East Asian, 43.2% White, and 2.2% Black patients. Median AI-ECG probabilities of HCM were 85% for patients with HCM and 0.3% for controls (P < 0.001). Overall, the AI-ECG algorithm had an area under the receiver operating characteristic curve (AUC) of 0.922 [95% confidence interval (CI) 0.910-0.934], with diagnostic accuracy 86.9%, sensitivity 82.8%, and specificity 87.7% for HCM detection. In age- and sex-matched analysis (case-control ratio 1:2), the AUC was 0.921 (95% CI 0.909-0.934) with accuracy 88.5%, sensitivity 82.8%, and specificity 90.4%. Conclusion: The AI-ECG algorithm determined HCM status from the 12-lead ECG with high accuracy in diverse international cohorts, providing evidence for external validity. The value of this algorithm in improving HCM detection in clinical practice and screening settings requires prospective evaluation.

Influenza Virus-Derived CD8 T Cell Epitopes: Implications for the Development of Universal Influenza Vaccines.

The influenza virus poses a global health burden. Currently, an annual vaccine is used to reduce influenza virus-associated morbidity and mortality. Most influenza vaccines have been developed to elicit neutralizing Abs against influenza virus. These Abs primarily target immunodominant epitopes derived from hemagglutinin (HA) or neuraminidase (NA) of the influenza virus incorporated in vaccines. However, HA and NA are highly variable proteins that are prone to antigenic changes, which can reduce vaccine efficacy. Therefore, it is essential to develop universal vaccines that target immunodominant epitopes derived from conserved regions of the influenza virus, enabling cross-protection among different virus variants. The internal proteins of the influenza virus serve as ideal targets for universal vaccines. These internal proteins are presented by MHC class I molecules on Ag-presenting cells, such as dendritic cells, and recognized by CD8 T cells, which elicit CD8 T cell responses, reducing the likelihood of disease and influenza viral spread by inducing virus-infected cell apoptosis. In this review, we highlight the importance of CD8 T cell-mediated immunity against influenza viruses and that of viral epitopes for developing CD8 T cell-based influenza vaccines.

Postoperative use of sleep aids and delirium in older adults after major surgery: A retrospective cohort study.

BACKGROUND: Sleep aids are commonly prescribed to treat sleep disturbance, a modifiable risk factor for postoperative delirium in older patients. The use of melatonin receptor agonists in the postoperative period has been increasing. The comparative safety of melatonin receptor agonists, zolpidem, and temazepam remains uncertain. METHODS: This retrospective study included 22,083 patients ≥65 years old who initiated melatonin receptor agonists, zolpidem, or temazepam after major surgery in the Premier Healthcare Database 2009-2018. We performed propensity score-based overlap weighting and estimated the risk ratio (RR) and risk difference (RD) of postoperative delirium as the primary outcome and a composite of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality as secondary outcomes. RESULTS: The mean age of the study population was 78 (SD, 7) years and 50% were female. There was no significant difference in the risk of postoperative delirium among patients treated with melatonin receptor agonists (3.4%, reference group), zolpidem (2.9%; RR [95% CI], 0.9 [0.7-1.2]; RD [95% CI] per 100 persons, -0.3 [-1.1 to 0.6]), and temazepam (3.1%; 0.9 [0.7-1.1]; RD [95% CI] per 100 persons, -0.5 [-1.2 to 0.3]). The risks of delirium or new antipsychotic initiation, pneumonia, and in-hospital mortality were also similar among all groups. CONCLUSIONS: Melatonin receptor agonists were not associated with a lower risk of postoperative delirium and other adverse outcomes compared with zolpidem and temazepam in older adults after major surgery.