LC-MS Approach to Decipher a Light Chain Chromatographic Peak Splitting of a Monoclonal Antibody

PURPOSE

Monoclonal antibodies (mAbs), like other protein therapeutics, are prone to various forms of degradation, some of which are difficult to distinguish from the native form yet may alter potency. A generalizable LC-MS approach was developed to enable quantitative analysis of isoAsp. In-depth understanding of product quality attributes (PQAs) enables optimization of the manufacturing process, better formulation selection, and decreases risk associated with product handling in the clinic or during shipment.

METHODS

Reversed-phase chromatographic peak splitting was observed when a mAb was exposed to elevated temperatures. Multiple LC-MS based methods were applied to identify the reason for peak splitting. The approach involved the use of complementary HPLC columns, multiple enzymatic digestions and different MS/MS ion dissociation methods. In addition, mAb potency was measured by enzyme-linked immunosorbent assay (ELISA).

RESULTS

The split peaks had identical masses, and the root cause of the peak splitting was identified as isomerization of an aspartic acid located in the complementarity-determining region (CDR) of the light chain. And the early eluting and late eluting peaks were collected and performed enzymatic digestion to confirm the isoAsp enrichment in the early eluting peak. In addition, decreased potency was observed in the same heat-stressed sample, and the increased isoAsp levels in the CDR correlate well with a decrease of potency.

CONCLUSION

Liquid chromatography-mass spectrometry (LC-MS) has been utilized extensively to assess PQAs of biological therapeutics. In this study, a generalizable LC-MS-based approach was developed to enable identification and quantitation of the isoAsp-containing peptides.

Sexual Orientation and Gender Identity (SOGI) Data Collection: Opportunities to Advance Best Clinical Practices for LGBTQ+ Patients in Radiation Oncology

PURPOSE/OBJECTIVE(S)

A long-standing barrier to progress against health disparities is the lack of data regarding cancer risks, prevalence, treatment, and outcomes for sexual and gender minority (SGM) patients. Sexual orientation and gender identity (SOGI) data are not routinely collected by individual oncologists, cancer centers, or most non-federal hospital systems. Alarmingly high proportions of SGM patients report discrimination in healthcare or avoid routine care due to perceived lack of acceptance in the healthcare system. For these and other reasons, healthcare institutions must adopt practices that promote an inclusive environment for all patients including those self-identified from SGM groups. One strategy to achieve this aim is through SOGI data collection. The purpose of this study was to pilot new procedures and training for SOGI data collection, the aims of this project were to standardize the collection of SOGI data for all new patients referred to the Division of Radiation Oncology; promote clinical staff awareness of SGM health disparities and strategies for fostering an inclusive hospital environment; and to provide SGM patients and caregivers educational resources and support systems tailored to their needs.

MATERIALS/METHODS

We designed a Quality Improvement program for collecting SOGI data, which was approved by our institution's QIAB. Patient access specialists (PAS) were trained to collect SOGI data from newly registered patients and enter the data into the electronic health record. Radiation Oncology staff completed surveys before and after SOGI training to estimate its impact on the provision of patient care. A Fisher's exact test was utilized to evaluate associations between training and provider-reported outcomes.

RESULTS

Within a 3-week period starting in January 2023, two 1-hour interactive training sessions were offered to twenty-five PAS. Three 1-hour training sessions were offered to twenty-seven Radiation Oncology clinical staff. (1) Confidence for incorporating SOGI classifiers around patients improved from before training (52%, 13/25) to after training (100%, 17/17) among medical providers surveyed (odds ratio (OR) 32, 95% confidence interval (CI) 0.70-1493, p = 0.005). Use of SOGI data in clinical decision making increased from before training (9/25, 36%) to after training (100%, 17/17) among medical providers (OR 60.79, 95% CI 3.271-1130, p<0.0001). (2) A clinical pathway for SGM patients was developed to facilitate referral to our institution's SGM patient support group and distribution of patient education materials focused on sexual health.

CONCLUSION

Establishing standardized SOGI data collection can facilitate the provision of tailored resources and care that meets the needs of patients and staff in a large comprehensive cancer center. Specialized training for staff developed through this initiative helps foster an inclusive and welcoming environment that promotes the integration, visibility, and advancement of SGM cancer care at our institution.

The effect of digital interventions on related health literacy and skills for individuals living with chronic diseases: A systematic review and meta-analysis

BACKGROUND

Chronic diseases are a leading cause of death and disease burden globally. Digital interventions could be an approach to improve patients' ability to find, evaluate, and use health information.

OBJECTIVES

The main objective was to conduct a systematic review to determine the effect of digital interventions on digital health literacy for patients living with chronic disease. Secondary objectives were to provide an overviewof the design and delivery characteristics of interventions that impact digital health literacy in people with chronic disease.

METHODS

Randomized controlled trials examining digital health literacy (and related components) for individuals with cardiovascular disease, chronic lung disease, osteoarthritis, diabetes, chronic kidney disease, and HIV were identified. This review was conducted following the PRIMSA guidelines. Certainty was assessed using GRADE and the Cochrane risk of bias tool. Meta-analyses were conducted using Review Manager 5.1. The protocol was registered on PROSPERO (CRD42022375967).

RESULTS

9386 articles were identified and 17 articles representing 16 unique trials were included. Studies evaluated 5138 individuals with one or more chronic conditions (50% women, ages 42 ± 7-71 ± 12 years). The most targeted conditions were cancer, diabetes, cardiovascular disease, and HIV. Interventions included: skills training, websites, electronic personal health records, remote patient monitoring, and education. The effects of the interventions were related to: (i) digital health literacy, (ii) health literacy, (iii) health information skills, (iv) technology skills and access, and (v) self-management and participation in care. A meta-analysis of three studies identified the effect of digital interventions was better than usual care for eHealth literacy (1.22 [CI 0.55, 1.89], p < 0.001).

CONCLUSIONS

The evidence of the effects of digital interventions on related health literacy is limited. Existing studies reflect the heterogeneity in study design, population, and outcome measures. There is a need for further studies on the effects of digital interventions on related health literacy for individuals with chronic conditions.

Leukocytes, microRNA, and complement activity in raw, heat-treated, and frozen colostrum and their dynamics as colostrum transitions to mature milk in dairy cows

The objectives of this study were to evaluate the abundance and viability of leukocytes, the abundance of microRNA, and the activity of the complement pathway in (1) colostrum following heat-treatment or freezing, and (2) colostrum, transition milk, and mature milk. In experiment 1, composite colostrum samples were harvested from individual cows (n = 14) on a commercial dairy farm in NY and split into 3 aliquots using single-use colostrum bags. One aliquot was immediately cooled on ice following harvest (RAW) and stored at 4°C overnight, one was heat-treated for 60 min at 60°C (HT) before being cooled on ice and stored at 4°C overnight, and one was frozen at -20°C overnight (FR). The following morning, all samples were warmed to 40°C before further processing. In experiment 2, cows were sampled in a longitudinal study where composite samples were collected from colostrum (first milking, n = 23), transition milk (3 to 4 d postpartum, n = 13), and mature milk (6 to 7 d postpartum, n = 13). In both experiments colostrum was harvested from the first milking within 8 h of calving and samples were processed within 14 h of collection. Colostral leukocytes were isolated before viability was determined by trypan blue exclusion and manual differential cell counts were performed. Extracellular vesicles were isolated from whey by ultracentrifugation to isolate and quantify microRNA. Activity of the alternative complement pathway was determined in casein-depleted whey by semi-solid phase hemolysis assay. Somatic cell counts were determined for all raw samples. Macrophages and neutrophils made up the greatest proportion of leukocytes in colostrum followed by lymphocytes. Lymphocyte proportion increased as colostrum transitioned to mature milk, but overall somatic cell numbers declined concurrently. Viable cells were not isolated from HT or FR samples. Abundance of microRNA isolated from transition and mature milk was decreased compared with colostrum, did not differ between HT and RAW, but was increased in FR compared with RAW. Alternative complement pathway activity was decreased in HT, but not FR compared with RAW, and was not measurable in transition or mature milk. Postharvest heat-treatment and freezing of colostrum eliminated viable colostral leukocytes and affected microRNA abundance and complement activity. Leukocyte proportions, microRNA abundance, and complement activity changed as colostrum transitioned to mature milk. Although there were clear changes in the colostral components under study in relation to treatment and transition to mature milk, the biological significance of the described treatment effects and temporal changes were not investigated here.

Invited Review: APOE at the interface of inflammation, neurodegeneration and pathological protein spread in Alzheimer's disease

Despite more than a century of research, the aetiology of sporadic Alzheimer's disease (AD) remains unclear and finding disease modifying treatments for AD presents one of the biggest medical challenges of our time. AD pathology is characterized by deposits of aggregated amyloid beta (Aβ) in amyloid plaques and aggregated tau in neurofibrillary tangles. These aggregates begin in distinct brain regions and spread throughout the brain in stereotypical patterns. Neurodegeneration, comprising loss of synapses and neurons, occurs in brain regions with high tangle pathology, and an inflammatory response of glial cells appears in brain regions with pathological aggregates. Inheriting an apolipoprotein E ε4 (APOE4) allele strongly increases the risk of developing AD for reasons that are not yet entirely clear. Substantial amounts of evidence support a role for APOE in modulating the aggregation and clearance of Aβ, and data have been accumulating recently implicating APOE4 in exacerbating neurodegeneration, tau pathology and inflammation. We hypothesize that APOE4 influences all the pathological hallmarks of AD and may sit at the interface between neurodegeneration, inflammation and the spread of pathologies through the brain. Here, we conducted a systematic search of the literature and review evidence supporting a role for APOE4 in neurodegeneration and inflammation. While there is no direct evidence yet for APOE4 influencing the spread of pathology, we postulate that this may be found in future based on the literature reviewed here. In conclusion, this review highlights the importance of understanding the role of APOE in multiple important pathological mechanisms in AD.

Repeat emergency department visits by nursing home residents: a cohort study using health administrative data

BACKGROUND

Nursing home (NH) residents are frequent users of emergency departments (ED) and while prior research suggests that repeat visits are common, there is little data describing this phenomenon. Our objectives were to describe repeat ED visits over one year, identify risk factors for repeat use, and characterize "frequent" ED visitors.

METHODS

Using provincial administrative data from Ontario, Canada, we identified all NH residents 65 years or older who visited an ED at least once between January 1 and March 31, 2010 and then followed them for one year to capture all additional ED visits. Frequent ED visitors were defined as those who had 3 or more repeat ED visits. We used logistic regression to estimate risk factors for any repeat ED visit and for being a frequent visitor and Andersen-Gill regression to estimate risk factors for the rate of repeat ED visits.

RESULTS

In a cohort of 25,653 residents (mean age 84.5 (SD = 7.5) years, 68.2% female), 48.8% had at least one repeat ED visit. Residents who experienced a repeat ED visit were generally similar to others but they tended to be slightly younger, have a higher proportion male, and a higher proportion with minimal cognitive or physical impairment. Risk factors for a repeat ED visit included: being male (adjusted odds ratio 1.27, (95% confidence interval 1.19-1.36)), diagnoses such as diabetes (AOR 1.28 (1.19-1.37)) and congestive heart failure (1.26 (1.16-1.37)), while severe cognitive impairment (AOR 0.92 (0.84-0.99)) and 5 or more chronic conditions (AOR 0.82 (0.71-0.95)) appeared protective. Eleven percent of residents were identified as frequent ED visitors, and they were more often younger then 75 years, male, and less likely to have Alzheimer's disease or other dementias than non-frequent visitors.

CONCLUSIONS

Repeat ED visits were common among NH residents but a relatively small group accounted for the largest number of visits. Although there were few clear defining characteristics, our findings suggest that medically complex residents and younger residents without cognitive impairments are at risk for such outcomes.

Postdischarge service utilisation and outcomes among Chinese and South Asian psychiatric inpatients in Ontario, Canada: a population-based cohort study

OBJECTIVE

We sought to examine the short-term and long-term impacts of psychiatric hospitalisations among patients of Chinese and South Asian origin.

DESIGN

Retrospective population-based cohort study using linked health administrative data.

SETTING

We examined all adult psychiatric inpatients discharged between 1 April 2006 and 31 March 2014 in Ontario, Canada, who were classified as Chinese, South Asian and all other ethnicities (ie, 'general population') using a validated algorithm. We identified 2552 Chinese, 2439 South Asian and 127 142 general population patients.

PRIMARY AND SECONDARY OUTCOME MEASURES

We examined psychiatric severity measures at admission and discharge and performed multivariable logistic regression analyses to examine 30-day, 180-day and 365-day postdischarge service utilisation and outcomes, comparing each of the ethnic groups with the reference population, after adjustment for age, sex, income, education, marital status, immigration status, community size and discharge diagnosis.

RESULTS

Despite presenting to hospital with greater illness severity, Asian psychiatric inpatients had shorter lengths of hospital stay and greater absolute improvements in mental health and functional status at discharge compared with other inpatients. After hospitalisation, Chinese patients were more likely to visit psychiatrists and South Asian patients were more likely to seek mental healthcare from general practitioners. They were also less likely to have a psychiatric readmission or die 1 year following hospitalisation (adjusted OR_Chinese=0.87; 95% CI 0.79 to 0.97; adjusted OR_{South Asian}=0.82, 95% CI 0.73 to 0.91). Findings were consistent across genders, psychiatric diagnoses and immigrant groups.

CONCLUSION

Once hospitalised, patients of Chinese and South Asian origin fared as well as or better than general population patients at discharge and following discharge, and had a positive trajectory of psychiatric service utilisation.

Impact of Physician Follow-Up Care on Psychiatric Readmission Rates in a Population-Based Sample of Patients With Schizophrenia

OBJECTIVE

The study evaluated the association between physician follow-up within 30 days after hospital discharge and psychiatric readmission within the subsequent 180 days.

METHODS

Among inpatients with schizophrenia who were discharged between 2007 and 2012 in Ontario (N=19,132), those who had a 30-day follow-up visit with a primary care physician (PCP) only, a psychiatrist only, or both were compared with a no-follow-up group. The primary outcome was psychiatric readmission in the subsequent 180 days. Secondary analyses stratified the sample on the basis of readmission risk at discharge.

RESULTS

About 65% of patients had follow-up care within 30 days postdischarge. Psychiatric readmission rates were similar among patients with any physician follow-up and significantly lower than among those with no follow-up (26%): PCP only: 22%; adjusted hazard ratio [aHR]=.88, 95% confidence interval [CI]=.81-.96; psychiatrist only, 22%; aHR=.84, CI=.77-.90; both, 21%, aHR=.82, CI=.75-.90). In stratified analyses, 66% of patients were in the category at highest risk of psychiatric readmission, and the effect of follow-up with any physician was significant for these patients, compared with high-readmission risk patients with no follow-up, who had a 29% readmission rate (PCP only, 20% readmission rate, aHR=.85, CI=.77-.94; psychiatrist only, 29%, aHR=.84, CI=.77-.92; both, 17%, aHR=.81, CI=.73-.90).

DISCUSSION

Timely physician follow-up was associated with reduced risk of psychiatric readmissions, with the greatest reduction among patients at high risk of readmission. Because more than one-third of patients had no physician visit within 30 days postdischarge, improving physician follow-up may help reduce psychiatric readmission rates.

Outcomes for Patients with apparent Chronic Idiopathic Pelvic Pain and associated Pelvic Floor Disorders undergoing Laparoscopic Ventral Mesh Rectopexy

This article has been temporarily withdrawn, with the agreement of all authors and the journal editor, whilst an investigated is being carried out by the North Bristol NHS Trust and the General Medical Council following some concerns raised.

Neurophysiological assessment of acute pain in infants: a scoping review of research methods

A systematic scoping search to describe the neurophysiological methods used in infant acute pain assessment research was conducted. Of the 2411 abstracts screened, 19 articles were retained. Nine studies utilised near-infrared spectroscopy (NIRS), two utilised functional magnetic resonance imaging (fMRI), and eight utilised electroencephalography (EEG). There was methodological variability in studies utilising NIRS, whereas EEG and fMRI studies reported consistent methods. Of the eight EEG studies, six identified a nociceptive-specific event-related potential.

CONCLUSION

While more methodologically rigorous studies are needed, ERPs appear to hold some promise as indicators of infant nociception during clinical procedures to supplement existing measures.

The Effect of Chronic Kidney Disease on a Physical Activity Intervention: Impact on Physical Function, Adherence, and Safety

Background

Because chronic kidney disease (CKD) is associated with muscle wasting, older adults with CKD are likely to have physical function deficits. Physical activity can improve these deficits, but whether CKD attenuates the benefits is unknown. Our objective was to determine if CKD modified the effect of a physical activity intervention in older adults.

Methods

This is an exploratory analysis of the LIFE-P study, which compared a 12-month physical activity program (PA) to a successful aging education program (SA) in older adults. CKD was defined as a baseline eGFR < 60 mL/min/1.73 m². We examined the Short Physical Performance Battery (SPPB) at baseline, 6 and 12 months. Secondary outcomes included serious adverse events (SAE) and adherence to intervention frequency. Linear mixed models were adjusted for age, sex, diabetes, hypertension, CKD, intervention, site, visit, baseline SPPB, and interactions of intervention and visit and of intervention, visit, and baseline CKD.

Results

The sample included 368 participants. CKD was present in 105 (28.5%) participants with a mean eGFR of 49.2 ± 8.1 mL/min/1.73 m². Mean SPPB was 7.38 ± 1.41 in CKD participants; 7.59 ± 1.44 in those without CKD (p = 0.20). For CKD participants in PA, 12-month SPPBs increased to 8.90 (95% CI 8.32, 9.47), while PA participants without CKD increased to 8.40 (95% CI 8.01, 8.79, p = 0.43). For CKD participants in SA, 12-month SPPBs increased to 7.67 (95% CI 7.07, 8.27), while participants without CKD increased to 8.12 (95% CI 7.72, 8.52, p = 0.86). Interaction between CKD and intervention was non-significant (p = 0.88). Number and type of SAEs were not different between CKD and non-CKD participants (all p > 0.05). In PA, adherence for CKD participants was 65.5 ± 25.4%, while for those without CKD was 74.0 ± 22.2% (p = 0.12).

Conclusion

Despite lower adherence, older adults with CKD likely derive clinically meaningful benefits from physical activity with no apparent impact on safety, compared to those without CKD.

Insulin pump use and discontinuation in children and teens: a population-based cohort study in Ontario, Canada

OBJECTIVE

To describe insulin pump use by youth since introduction of universal funding in Ontario, Canada and to explore the relationship between pump use and pediatric diabetes center characteristics and the relationship between discontinuation and center and patient characteristics.

RESEARCH DESIGN AND METHODS

Observational, population-based cohort study of youth with type 1 diabetes (<19 yr) who received pump funding from 2006 to 2013 (n = 3700). We linked 2012 survey data from 33 pediatric diabetes centers to health administrative databases. We tested the relationship between center-level pump uptake and center characteristics (center type, physician model, and availability of 24-h support) using an adjusted negative binomial model; we studied center- and patient-level factors (socioeconomic status and baseline glycemic control) associated with discontinuation using a Cox proportional hazards model with generalized estimating equations.

RESULTS

Pump users were more likely to be in the highest income quintile than non-pump users (29.6 vs. 19.1%, p < 0.0001). In 2012, mean percent pump use was 38.0% with variability across centers. There was no association between uptake and center characteristics. Discontinuation was low (0.42/100 person-yr) and was associated with being followed at a small community center [hazard ratio (HR): 2.24 (1.05-4.76)] and being more deprived [HR: 2.36 (1.14-1.48)]. Older age was associated with a lower rate of discontinuation [HR: 0.31 (0.14-0.66)].

CONCLUSIONS

Rates of pump use have increased since 2006 and discontinuation is rare. Large variation in uptake across centers was not explained by the factors we examined but may reflect variation in patient populations or practice patterns, and should be further explored.

Variation in Emergency Department Transfer Rates from Nursing Homes in Ontario, Canada

BACKGROUND

Nursing home (NH) residents are frequently transferred to the emergency department (ED) but there is little data on inter-facility variation, which has implications for intervention planning and implementation.

OBJECTIVES

To describe variation in ED transfer rates (TRs) across NHs and the association with NH characteristics.

DESIGN/SETTING

Retrospective cohort study using linked administrative data from Ontario.

PARTICIPANTS

71,780 residents of 604 NHs in 2010 and followed for one year.

MEASUREMENTS

Funnel plots were used to identify high transfer NHs and logistic regression to test the association with NH location, size, ownership and historical ED transfer rate.

RESULTS

One-year ED transfer rates ranged from 4.3% to 58.6% (mean 28.4%); 115 (19%) NHs were considered high. Being within five minutes of an ED, larger size and high historical ED transfer rate were associated with being a high ED transfer home.

CONCLUSION

There was substantial variation across NHs. Consideration of characteristics such as proximity to an ED may be important in the development and targeting of different interventions for NHs.

Low socioeconomic status is associated with adverse events in children and teens on insulin pumps under a universal access program: a population-based cohort study

OBJECTIVE

To describe adverse events in pediatric insulin pump users since universal funding in Ontario and to explore the role of socioeconomic status and 24-hour support.

RESEARCH DESIGN AND METHODS

Population-based cohort study of youth (<19 years) with type 1 diabetes (n=3193) under a universal access program in Ontario, Canada, from 2006 to 2013. We linked 2012 survey data from 33 pediatric diabetes centers to health administrative databases. The relationship between patient and center-level characteristics and time to first diabetic ketoacidosis (DKA) admission or death was tested using a Cox proportional hazards model and the rate of diabetes-related emergency department visits and hospitalizations with a Poisson model, both using generalized estimating equations.

RESULTS

The rate of DKA was 5.28/100 person-years and mortality 0.033/100 person-years. Compared with the least deprived quintile, the risk of DKA or death for those in the most deprived quintile was significantly higher (HR 1.58, 95% CI 1.05 to 2.38) as was the rate of diabetes-related acute care use (RR 1.60, 95% CI 1.27 to 2.00). 24-hour support was not associated with these outcomes. Higher glycated hemoglobin, prior DKA, older age, and higher nursing patient load were associated with a higher risk of DKA or death.

CONCLUSIONS

The safety profile of pump therapy in the context of universal funding is similar to other jurisdictions and unrelated to 24-hour support. Several factors including higher deprivation were associated with an increased risk of adverse events and could be used to inform the design of interventions aimed at preventing poor outcomes in high-risk individuals.

Impact of dietary plane of energy during the dry period on lipoprotein parameters in the transition period in dairy cattle

The high energy demands of dairy cows during the transition period from late gestation into early lactation can place them at an increased risk for the development of metabolic and infectious diseases. Modification of the dry period diet has been investigated as a preventive means to minimize the detrimental aspects of metabolic shifts during the transition period. Studies investigating the impact of dry period diet on lipid parameters during the transition period have largely focused on markers of lipolysis and ketogenesis. Total cholesterol declines during the periparturient period and increases in early lactation. The impact total energy in the dry period diet has on the ability of the cow to maintain total serum cholesterol, as well as its natural high-density lipoprotein-rich status, during this metabolically challenging window is not clear. The impact of lipoproteins on inflammation and immune function may have a clinical impact on the cow's ability to ward off production-related diseases. In this study, we hypothesized that the provision of adequate, but not excessive, total metabolizable energy, would better allow the cow to maintain total cholesterol and a higher relative proportion of HDL throughout the transition period. Cows were allocated to one of three dry period dietary treatment groups following a randomized block design. Total serum triglycerides, cholesterol and lipoprotein fractions were measured on a weekly basis from approximately 7 weeks pre-calving to 6 weeks post-calving. The cows on the high energy diet maintained total serum cholesterol as compared to the cows provided a lower energy diet, but there was no significant increase in the LDL fraction of lipoproteins between diet treatment groups.

Arterialized venous bicarbonate is associated with lower bone mineral density and an increased rate of bone loss in older men and women

CONTEXT

Higher dietary net acid loads have been associated with increased bone resorption, reduced bone mineral density (BMD), and increased fracture risk.

OBJECTIVE

The objective was to compare bicarbonate (HCO3) measured in arterialized venous blood samples to skeletal outcomes.

DESIGN

Arterialized venous samples collected from participants in the Health, Aging and Body Composition (Health ABC) Study were compared to BMD and rate of bone loss.

SETTING

The setting was a community-based observational cohort.

PARTICIPANTS

A total of 2287 men and women age 74 ± 3 years participated.

INTERVENTION

Arterialized venous blood was obtained at the year 3 study visit and analyzed for pH and pCO2. HCO3 was determined using the Henderson-Hasselbalch equation.

MAIN OUTCOME MEASURE

BMD was measured at the hip by dual-energy x-ray absorptiometry at the year 1 (baseline) and year 3 study visits.

RESULTS

Plasma HCO3 was positively associated with BMD at both year 1 (P = .001) and year 3 (P = .001) in models adjusted for age, race, sex, clinic site, smoking, weight, and estimated glomerular filtration rate. Plasma HCO3 was inversely associated with rate of bone loss at the total hip over the 2.1 ± 0.3 (mean ± SD) years between the two bone density measurements (P < .001). Across quartiles of plasma HCO3, the rate of change in BMD over the 2.1 years ranged from a loss of 0.72%/y in the lowest quartile to a gain of 0.15%/y in the highest quartile of HCO3.

CONCLUSIONS

Arterialized plasma HCO3 was associated positively with cross-sectional BMD and inversely with the rate of bone loss, implying that systemic acid-base status is an important determinant of skeletal health during aging. Ongoing bone loss was linearly related to arterialized HCO3, even after adjustment for age and renal function. Further research in this area may have major public health implications because reducing dietary net acid load is possible through dietary intervention or through supplementation with alkaline potassium compounds.

Influenza and seasonal patterns of hospital use by older adults in long-term care and community settings in Ontario, Canada

OBJECTIVES

We compared seasonal influenza hospital use among older adults in long-term care (LTC) and community settings.

METHODS

We used provincial administrative data from Ontario to identify all emergency department (ED) visits and hospital admissions for pneumonia and influenza among adults older than 65 years between 2002 and 2008. We used sentinel laboratory reports to define influenza and summer seasons and estimated mean annual event rates and influenza-associated rates.

RESULTS

Mean annual pneumonia and influenza ED visit rates were higher in LTC than the community (rate ratio [RR] for influenza season = 3.9; 95% confidence interval [CI] = 3.8, 4.0; for summer = 4.9; 95% CI = 4.8, 5.1) but this was attenuated in influenza-associated rates (RR = 2.4; 95% CI = 2.1, 2.8). The proportion of pneumonia and influenza ED visits attributable to seasonal influenza was 17% (15%-20%) in LTC and 28% (27%-29%) in the community. Results for hospital admissions were comparable.

CONCLUSIONS

We found high rates of hospital use from LTC but evidence of lower impact of circulating influenza in the community. This differential impact of circulating influenza between the 2 environments may result from different influenza control policies.

Maternal and newborn outcomes among women with schizophrenia: a retrospective population-based cohort study

OBJECTIVE

More women with schizophrenia are becoming pregnant, such that contemporary data are needed about maternal and newborn outcomes in this potentially vulnerable group. We aimed to quantify maternal and newborn health outcomes among women with schizophrenia.

DESIGN

Retrospective cohort study.

SETTING

Population based in Ontario, Canada, from 2002 to 2011.

POPULATION

Ontario women aged 15-49 years who gave birth to a liveborn or stillborn singleton infant.

METHODS

Women with schizophrenia (n = 1391) were identified based on either an inpatient diagnosis or two or more outpatient physician service claims for schizophrenia within 5 years prior to conception. The reference group comprised 432 358 women without diagnosed mental illness within the 5 years preceding conception in the index pregnancy.

MAIN OUTCOME MEASURES

The primary maternal outcomes were gestational diabetes mellitus, gestational hypertension, pre-eclampsia/eclampsia, and venous thromboembolism. The primary neonatal outcomes were preterm birth, and small and large birthweight for gestational age (SGA and LGA). Secondary outcomes included additional key perinatal health indicators.

RESULTS

Schizophrenia was associated with a higher risk of pre-eclampsia (adjusted odds ratio, aOR 1.84; 95% confidence interval, 95% CI 1.28-2.66), venous thromboembolism (aOR 1.72, 95% CI 1.04-2.85), preterm birth (aOR 1.75, 95% CI 1.46-2.08), SGA (aOR 1.49, 95% CI 1.19-1.86), and LGA (aOR 1.53, 95% CI 1.17-1.99). Women with schizophrenia also required more intensive hospital resources, including operative delivery and admission to a maternal intensive care unit, paralleled by higher neonatal morbidity.

CONCLUSIONS

Women with schizophrenia are at higher risk of multiple adverse pregnancy outcomes, paralleled by higher neonatal morbidity. Attention should focus on interventions to reduce the identified health disparities.

Prolonged antibiotic treatment in long-term care: role of the prescriber

IMPORTANCE

Given that most common bacterial infections can be treated with antibiotic courses of 7 or fewer days, reducing standard antibiotic treatment durations may be an avenue to curtailing antibiotic overuse in long-term care.

OBJECTIVES

To describe the variability in the duration of antibiotic treatment courses in long-term care across resident recipients and prescribing physicians and to determine whether this variability is influenced by prescriber preference.

DESIGN AND SETTING

Province-wide retrospective analysis of residents of Ontario, Canada, long-term care facilities in 2010.

PARTICIPANTS

All adults aged 66 years or older who received an incident treatment course with a systemic antibiotic while residing in an Ontario long-term care facility.

MAIN OUTCOME MEASURE

Antibiotic treatment duration was examined across residents and prescribing physicians. The proportion of a physician's treatment courses that exceeded 7 days was used to classify short-, average-, and long-duration prescribers.

RESULTS

Of 66 901 long-term care residents from 630 long-term care facilities, 50 061 (77.8%) received an incident antibiotic treatment course (with 51 540 antibiotic courses prescribed). The most commonly selected antibiotic treatment course was 7 days (in 21 136 courses [41.0%]), but 23 124 (44.9%) exceeded 7 days. Among the 699 physicians responsible for 20 or more antibiotic treatment courses, the median (interquartile range) proportion of treatment courses beyond 7 days was 43.5% (26.9%-62.9%) (range, 0%-97.1%). Twenty-one percent of prescribers had a higher-than-expected proportion of prescriptions beyond the 7-day threshold. Patient characteristics were similar across short-, average-, and long-duration prescribers. A mixed logistic model confirmed that prescribers were an important determinant of treatment duration (P < .001), with a relative odds of prolonged prescription of 3.84 for 75th vs 25th percentile prescribers.

CONCLUSIONS AND RELEVANCE

Antibiotic treatment courses in long-term care facilities are often prescribed for long durations, and this appears to be influenced by prescriber preference more than patient characteristics. Future trials should evaluate antibiotic stewardship interventions targeting prescriber preferences to systematically shorten average treatment durations to reduce the complications, costs, and resistance associated with antibiotic overuse.