Use of Nonhuman Sera as a Highly Cost-Effective Internal Standard for Quantitation of Multiple Human Proteins Using Species-Specific Tryptic Peptides: Applicability in Clinical LC-MS Analyses.

Quantitation of proteins using liquid chromatography-tandem mass spectrometry (LC-MS/MS) is complex, with a multiplicity of options ranging from label-free techniques to chemically and metabolically labeling proteins. Increasingly, for clinically relevant analyses, stable isotope-labeled (SIL) internal standards (ISs) represent the "gold standard" for quantitation due to their similar physiochemical properties to the analyte, wide availability, and ability to multiplex to several peptides. However, the purchase of SIL-ISs is a resource-intensive step in terms of cost and time, particularly for screening putative biomarker panels of hundreds of proteins. We demonstrate an alternative strategy utilizing nonhuman sera as the IS for quantitation of multiple human proteins. We demonstrate the effectiveness of this strategy using two high abundance clinically relevant analytes, vitamin D binding protein [Gc globulin] (DBP) and albumin (ALB). We extend this to three putative risk markers for cardiovascular disease: plasma protease C1 inhibitor (SERPING1), annexin A1 (ANXA1), and protein kinase, DNA-activated catalytic subunit (PRKDC). The results show highly specific, reproducible, and linear measurement of the proteins of interest with comparable precision and accuracy to the gold standard SIL-IS technique. This approach may not be applicable to every protein, but for many proteins it can offer a cost-effective solution to LC-MS/MS protein quantitation.

The Effect of COVID-19 Vaccination on Outpatient Antibiotic Prescribing in Older Adults: A Self-Controlled Risk-Interval Study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccination has been associated with reduced outpatient antibiotic prescribing among older adults with laboratory-confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We assessed the impact of COVID-19 vaccination on outpatient antibiotic prescribing in the broader population of older adults, regardless of SARS-CoV-2 infection status. METHODS: We included adults aged ≥65 years who received their first, second, and/or third COVID-19 vaccine dose from December 2020 to December 2022. We used a self-controlled risk-interval design and included cases who received an antibiotic prescription 2-6 weeks before vaccination (pre-vaccination or control interval) or after vaccination (post-vaccination or risk interval). We used conditional logistic regression to estimate the odds of being prescribed (1) any antibiotic, (2) a typical "respiratory" infection antibiotic, or (3) a typical "urinary tract" infection antibiotic (negative control) in the post-vaccination interval versus the pre-vaccination interval. We accounted for temporal changes in antibiotic prescribing using background monthly antibiotic prescribing counts. RESULTS: 469 923 vaccine doses met inclusion criteria. The odds of receiving any antibiotic or a respiratory antibiotic prescription were lower in the post-vaccination versus pre-vaccination interval (aOR, .973; 95% CI, .968-.978; aOR, .961; 95% CI, .953-.968, respectively). There was no association between vaccination and urinary antibiotic prescriptions (aOR, .996; 95% CI, .987-1.006). Periods with high (>10%) versus low (<5%) SARS-CoV-2 test positivity demonstrated greater reductions in antibiotic prescribing (aOR, .875; 95% CI, .845-.905; aOR, .996; 95% CI, .989-1.003, respectively). CONCLUSIONS: COVID-19 vaccination was associated with reduced outpatient antibiotic prescribing in older adults, especially during periods of high SARS-CoV-2 circulation.

Circulating sphingolipids and relationship to cardiac remodelling before and following a low-energy diet in asymptomatic Type 2 Diabetes.

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a heterogenous multi-system syndrome with limited efficacious treatment options. The prevalence of Type 2 diabetes (T2D) continues to rise and predisposes patients to HFpEF, and HFpEF remains one of the biggest challenges in cardiovascular medicine today. Novel therapeutic targets are required to meet this important clinical need. Deep phenotyping studies including -OMIC analyses can provide important pathogenic information to aid the identification of such targets. The aims of this study were to determine; 1) the impact of a low-energy diet on plasma sphingolipid/ceramide profiles in people with T2D compared to healthy controls and, 2) if the change in sphingolipid/ceramide profile is associated with reverse cardiovascular remodelling. METHODS: Post-hoc analysis of a randomised controlled trial (NCT02590822) including adults with T2D with no cardiovascular disease who completed a 12-week low-energy (∼810 kcal/day) meal-replacement plan (MRP) and matched healthy controls (HC). Echocardiography, cardiac MRI and a fasting blood for lipidomics were undertaken pre/post-intervention. Candidate biomarkers were identified from case-control comparison (fold change > 1.5 and statistical significance p < 0.05) and their response to the MRP reported. Association between change in biomarkers and change indices of cardiac remodelling were explored. RESULTS: Twenty-four people with T2D (15 males, age 51.1 ± 5.7 years), and 25 HC (15 male, 48.3 ± 6.6 years) were included. Subjects with T2D had increased left ventricular (LV) mass:volume ratio (0.84 ± 0.13 vs. 0.70 ± 0.08, p < 0.001), increased systolic function but impaired diastolic function compared to HC. Twelve long-chain polyunsaturated sphingolipids, including four ceramides, were downregulated in subjects with T2D at baseline. Three sphingomyelin species and all ceramides were inversely associated with LV mass:volume. There was a significant increase in all species and shift towards HC following the MRP, however, none of these changes were associated with reverse cardiac remodelling. CONCLUSION: The lack of association between change in sphingolipids/ceramides and reverse cardiac remodelling following the MRP casts doubt on a causative role of sphingolipids/ceramides in the progression of heart failure in T2D. TRIAL REGISTRATION: NCT02590822.

Associations between specialized dementia care, COVID-19 and central nervous system medication use in assisted living: a population-based repeated cross-sectional study.

BACKGROUND: Assisted living (AL) is an increasingly common residential setting for persons with dementia; yet concerns exist about sub-optimal care of this population in AL given its lower levels of staffing and services. Our objectives were to (i) examine associations between AL setting (dementia care vs. other), COVID-19 pandemic waves, and prevalent antipsychotic, antidepressant, anti-dementia, benzodiazepine, and anticonvulsant drug use among residents with dementia/cognitive impairment, and (ii) explore associations between resident and home characteristics and prevalent medication use. METHODS: We conducted a population-based, repeated cross-sectional study using linked clinical and health administrative databases for all publicly funded AL homes in Alberta, Canada, examined between January 2018 - December 2021. The quarterly proportion of residents dispensed a study medication was examined for each setting and period (pandemic vs. comparable historical [2018/2019 combined]) focusing on four pandemic waves (March-May 2020, September 2020-February 2021, March-May 2021, September-December 2021). Log-binomial GEE models estimated prevalence ratios (PR) for period (pandemic vs. historical periods), setting (dementia care vs. other) and period-setting interactions, adjusting for resident (age, sex) and home (COVID-19 cases, health region, ownership) characteristics. RESULTS: On March 1, 2020, there were 2,779 dementia care and 3,013 other AL residents (mean age 83, 69% female) with dementia/cognitive impairment. Antipsychotic use increased during waves 2-4 in both settings, but this was more pronounced in dementia care than other AL during waves 3 and 4 (e.g., adjusted [adj]PR 1.20, 95% CI 1.14-1.27 vs. adjPR 1.09, 95% CI 1.02-1.17, interaction p = 0.023, wave 3). Both settings showed a statistically significant but modest increase in antidepressant use and decrease in benzodiazepine use. For dementia care AL residents only, there was a statistically significant increase in gabapentinoid use during several waves (e.g., adjPR 1.32, 95% CI 1.10-1.59, wave 3). Other than a modest decrease in prevalent anti-dementia drug use for both settings in wave 2, no other significant pandemic effects were observed. CONCLUSIONS: The persistence of the pandemic-associated increase in antipsychotic and antidepressant use in AL residents coupled with a greater increase in antipsychotic and gabapentinoid use for dementia care settings raises concerns about the attendant risks for residents with cognitive impairment.

Prescribing Trends for Oral Vancomycin and Fidaxomicin after Guideline and Formulary Changes in Ontario, Canada: An Interrupted Time-Series Analysis.

Background: Clostridioides difficile is a pathogen causing diarrheal illness, which can be treated with vancomycin or fidaxomicin. Objective: To evaluate changes in monthly prescription volumes for oral vancomycin and fidaxomicin in Ontario community pharmacies following implementation of the 2017 and 2021 updates to guidelines from the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA) and after a 2019 provincial formulary change for vancomycin. Methods: An interrupted time-series analysis was conducted from November 2015 to October 2021 using monthly projected prescription volumes obtained from IQVIA's Compuscript database. Level and slope (trend) changes in prescribing were assessed using segmented linear regression. Results: The volume of vancomycin prescriptions increased by 74 prescriptions per month (95% confidence interval [CI] 16 to 132) following implementation of the 2017 guideline update and by 73 prescriptions per month (95% CI 13 to 133) after the 2019 formulary change; however, no statistically significant changes were observed after implementation of the 2021 guideline update. No significant trend changes were observed for fidaxomicin. Conclusion: Guidelines and formulary changes were correlated with increased volume of vancomycin prescriptions.

Contexte: Le Clostridioides difficile est un agent pathogène provoquant une maladie diarrhéique pouvant être traitée avec de la vancomycine ou de la fidaxomicine. Objectif: Évaluer les changements de volume mensuel des prescriptions de vancomycine et de fidaxomicine par voie orale dans les pharmacies communautaires de l'Ontario après la mise en œuvre des lignes directrices actualisées en 2017 et 2021 de l'Infectious Diseases Society of America (IDSA) et de la Society for Healthcare Epidemiology of America (SHEA) et à la suite d'une modification au régime d'assurance-médicaments pour la vancomycine à l'échelle provinciale en 2019. Méthodologie: Une analyse de séries chronologiques interrompues a été réalisée de novembre 2015 à octobre 2021 à l'aide des volumes mensuels de prescriptions projetés qui ont été obtenus grâce à la base de données Compuscript d'IQVIA. Les changements du volume des prescriptions et de son évolution dans le temps (le niveau et la pente, respectivement) ont été évalués à l'aide d'une régression linéaire segmentée. Résultats: Le volume des prescriptions de vancomycine a augmenté de 74 prescriptions par mois (intervalle de confiance [IC] à 95 % 16­132) après la mise en œuvre des lignes directrices actualisées en 2017; il a augmenté de 73 prescriptions par mois (IC à 95 % 13­133) après la modification du régime d'assurance-médicaments de 2019; cependant, aucun changement statistiquement significatif n'a été observé après la mise en œuvre des lignes directrices actualisées en 2021. Aucun changement significatif de tendance n'a été observé pour la fidaxomicine. Conclusion: Les lignes directrices et les modifications du régime d'assurance-médicaments étaient corrélées à une augmentation du volume des prescriptions de vancomycine.

The association between memory, COVID-19 testing, and COVID-19 incidence in middle-aged and older adults: a prospective analysis of the CLSA.

We investigated the association between pre-COVID-19 memory function and (a) receipt of a COVID-19 test and (b) incidence of COVID-19 using the COVID-19 Questionnaire Study (CQS) of the Canadian Longitudinal Study on Aging (CLSA). The CQS included 28,565 middle-aged and older adults. We regressed receipt of a COVID-19 test on participants' immediate and delayed recall memory scores and re-ran the regression models with COVID-19 incidence as the outcome. All regression models were adjusted for sociodemographic, lifestyle, and health covariates. In the analytical sample (n = 21,930), higher delayed recall memory (better memory) was significantly associated with lower COVID-19 incidence. However, this association was not significant for immediate recall memory. Immediate and delayed recall memory were not associated with receipt of a COVID-19 test. Health policymakers and practitioners may viewmemory status as a potential risk for COVID-19. Memory status may not be a barrier to COVID-19 testing.

Excess Deaths in Assisted Living and Nursing Homes during the COVID-19 Pandemic in Alberta, Canada.

OBJECTIVES: Assisted living (AL) is a significant and growing congregate care option for vulnerable older adults designed to reduce the use of nursing homes (NHs). However, work on excess mortality in congregate care during the COVID-19 pandemic has primarily focused on NHs with only a few US studies examining AL. The objective of this study was to assess excess mortality among AL and NH residents with and without dementia or significant cognitive impairment in Alberta, Canada, during the first 2 years of the COVID-19 pandemic, relative to the 3 years before. DESIGN: Population-based, retrospective cohort study. SETTING AND PARTICIPANTS: Residents who lived in an AL or NH facility operated or contracted by the Provincial health care system to provide publicly funded care in Alberta between January 1, 2017, and December 31, 2021. METHODS: We used administrative health care data, including Resident Assessment Instrument - Home Care (RAI-HC, AL) and Minimum Data Set 2.0 (RAI-MDS 2.0, NHs) records, linked with data on residents' vital statistics, COVID-19 testing, emergency room registrations, and hospital stays. The outcome was excess deaths during COVID-19 (ie, the number of deaths beyond that expected based on pre-pandemic data), estimated, using overdispersed Poisson generalized linear models. RESULTS: Overall, the risk of excess mortality [adjusted incidence rate ratio (95% confidence interval)] was higher in ALs than in NHs [1.20 (1.14-1.26) vs 1.10 (1.07-1.13)]. Weekly peaks in excess deaths coincided with COVID-19 pandemic waves and were higher among those with diagnosed dementia or significant cognitive impairment in both, AL and NHs. CONCLUSIONS AND IMPLICATIONS: Finding excess mortality within both AL and NH facilities should lead to greater focus on infection prevention and control measures across all forms of congregate housing for vulnerable older adults. The specific needs of residents with dementia in particular will have to be addressed.

Antipsychotic Discontinuation and New Trazodone Use in Ontario Nursing Homes: Evidence of Medication Substitution.

OBJECTIVES: An unintended consequence of efforts to reduce antipsychotic medications in nursing homes is the increase in use of other psychotropic medications; however, evidence of substitution remains limited. Our objective was to measure individual-level prescribing patterns consistent with substitution of trazodone for antipsychotics. DESIGN: Retrospective cohort study. SETTING AND PARTICIPANTS: Residents of Ontario nursing homes aged 66-105 years with an admission assessment between April 1, 2010, and March 31, 2019, who were receiving an antipsychotic and had no antidepressant medication use at admission to the nursing home. METHODS: We used linked health administrative data to examine changes in medication use over three quarterly assessments following admission. Antipsychotic and trazodone use were measured at each assessment. The rate of trazodone initiation was compared between residents no longer dispensed an antipsychotic (discontinued) and those with an ongoing antipsychotic (continued) using discrete time survival analysis, controlling for baseline resident characteristics. RESULTS: We identified 13,306 residents dispensed an antipsychotic with no antidepressant use at admission (mean age 84 years, 61.5% women, 82.8% with dementia). As of the first quarterly assessment, nearly 20% of residents no longer received an antipsychotic and 9% received a new trazodone medication. Over time, residents who discontinued antipsychotics had a rate of trazodone initiation that was 82% higher compared to residents who continued (adjusted hazard ratio 1.82, 95% CI 1.66-2.00). CONCLUSIONS AND IMPLICATIONS: Residents admitted to a nursing home with antipsychotic use had a higher rate of trazodone initiation if they discontinued (vs continued) an antipsychotic. These findings suggest antipsychotic substitution with trazodone after entering a nursing home.

Comparison of hospitalization events among residents of assisted living and nursing homes during COVID-19: Do settings respond differently during public health crises?

BACKGROUND: COVID-19 and resulting health system and policy decisions led to significant changes in healthcare use by nursing homes (NH) residents. It is unclear whether healthcare outcomes were similarly affected among older adults in assisted living (AL). This study compared hospitalization events in AL and NHs during COVID-19 pandemic waves 1 through 4, relative to historical periods. METHODS: This was a population-based, repeated cross-sectional study using linked clinical and health administrative databases (January 2018 to December 2021) for residents of all publicly subsidized AL and NH settings in Alberta, Canada. Setting-specific monthly cohorts were derived for pandemic (starting March 1, 2020) and comparable historical (2018/2019 combined) periods. Monthly rates (per 100 person-days) of all-cause hospitalization, hospitalization with delayed discharge, and hospitalization with death were plotted and rate ratios (RR) estimated for period (pandemic wave vs historical comparison), setting (AL vs NH) and period-setting interactions, using Poisson regression with generalized estimating equations, adjusting for resident and home characteristics. RESULTS: On March 1, 2020, there were 9,485 AL and 14,319 NH residents, comparable in age (mean 81 years), sex (>60% female) and dementia prevalence (58-62%). All-cause hospitalization rates declined in both settings during waves 1 (AL: adjusted RR 0.60, 95%CI 0.51-0.71; NH: 0.74, 0.64-0.85) and 4 (AL: 0.76, 0.66-0.88; NH: 0.65, 0.56-0.75) but unlike NHs, AL rates were not significantly lower during wave 2 (and increased 27% vs NH, January 2021). Hospitalization with delayed discharge increased in NHs only (during and immediately after wave 1). Both settings showed a significant increase in hospitalization with death in wave 2, this increase was larger and persisted longer for AL. CONCLUSIONS: Pandemic-related changes in hospitalization events differed for AL and NH residents and by wave, suggesting unique system and setting factors driving healthcare use and outcomes in these settings in response to this external stress.