Comparison of Acute Health Care Utilization Between Patients Receiving In-Center Hemodialysis and the General Population: A Population-Based Matched Cohort Study From Ontario, Canada.

Background: Patients receiving maintenance hemodialysis have multiple comorbidities and are at high risk of presenting to the hospital. However, the incidence and cost of acute health care utilization in the in-center hemodialysis population and how this compares with other populations is poorly understood. Objective: To determine the rate, pattern, and cost of emergency department visits and hospitalizations in patients receiving in-center hemodialysis compared with a matched general population. Design: Population-based matched cohort study. Setting: We used linked administrative health care databases from Ontario, Canada. Patients: We included 25 379 patients (incident and prevalent) receiving in-center hemodialysis between January 1, 2010, and December 31, 2018. Patients were matched on birth date (±2 years), sex, and cohort entry date using a 1:4 ratio to 101 516 individuals from the general population. Measurements: Our primary outcomes were emergency department visits (allowing for multiple visits per individual) and hospital admissions from the emergency department. We also assessed all-cause hospitalizations, all-cause readmissions within 30 days of discharge from the original hospitalization, length of stay for hospital admissions (including multiple visits per individual), and the financial cost of these admissions. Methods: We presented the rate, percentage, median (25th, 75th percentiles), and incidence rate per 1000 person-years for emergency department visits and hospitalizations. Individual-level health care costs for emergency department visits and all-cause hospitalization were estimated using resource intensity weights multiplied by the cost per weighted case. Results: Patients receiving in-center hemodialysis had substantially more comorbidities (eg, diabetes) than the matched general population. Eighty percent (n = 20 309) of patients receiving in-center hemodialysis had at least 1 emergency department visit compared with 56% (n = 56 452) of individuals in the matched general population, over a median follow-up of 1.8 years (25th, 75th percentiles: 0.7, 3.6) and 5.2 (2.5, 8.4) years, respectively. The incidence rate of emergency department visits, allowing for multiple visits per individual, was 2274 per 1000 person-years (95% confidence interval [CI]: 2263, 2286) for patients receiving in-center hemodialysis, which was almost 5 times as high as the matched general population (471 per 1000 person-years; 95% CI: 469, 473). The rate of hospital admissions from the emergency department and the rate of all-cause hospital admissions in the in-center hemodialysis population was more than 7 times as high as the matched general population (hospital admissions from the emergency department: 786 vs 101 per 1000 person-years; all-cause hospital admissions: 1056 vs 139 per 1000 person-years). The median number of all-cause hospitalization days per patient year was 4.0 (0, 16.5) in the in-center hemodialysis population compared with 0 (0, 0.5) in the matched general population. The cost per patient-year for emergency department visits in the in-center hemodialysis population was approximately 5.5 times as high as the matched general population while the cost of hospitalizations in the in-center hemodialysis population was approximately 11 times as high as the matched general population (emergency department visits: CAN$ 1153 vs CAN$ 209; hospitalizations: CAN$ 21 151 vs CAN$ 1873 [all costs in 2023 CAN$]). Limitations: External generalizability and we could not determine whether emergency department visits and hospitalizations were preventable. Conclusions: Patients receiving in-center hemodialysis have high acute health care utilization. These results improve our understanding of the burden of disease and the associated costs in the in-center hemodialysis population, highlight the need to improve acute outcomes, and can aid health care capacity planning. Additional research is needed to address the risk of hospitalization after controlling for patient comorbidities. Trial registration: This is not applicable as this is a population-based matched cohort study and not a clinical trial.

Contexte: Les patients qui suivent des traitements d'hémodialyse d'entretien présentent de multiples comorbidités et sont hautement susceptibles de se présenter à l'hôpital. On en sait toutefois peu sur l'incidence de l'utilization des soins de santé aigus chez les patients hémodialysés en center, sur les coûts qui y sont associés, ainsi que sur la manière dont cela se compare à d'autres populations. Objectif: Déterminer, dans une population de patients hémodialysés en center, les taux d'hospitalizations et de visites aux urgences, leurs schémas et les coûts qui y sont associés, puis comparer ces résultats à ceux d'une population générale appariée. Type d'étude: Étudede cohorte populationnelle rétrospective. Cadre: Nous avons utilisé les bases de données couplées du système de santé de l'Ontario (Canada). Sujets: Nous avons inclus 25 379 patients (incidents et prévalents) qui recevaient des traitements d'hémodialyse en center entre le 1er janvier 2010 et le 31 décembre 2018. Les patients inclus ont été appariés,en fonction de leur date de naissance (± 2 ans), de leur sexe et de leur date d'entrée dans la cohorte, à 101 516 individus de la population générale dans un rapport de 1:4. Mesures: Nos principaux critères de jugement étaient les visites aux urgences (en permettant plusieurs visites par personne) et les admissions à l'hôpital à partir de l'urgence. Nous avons également évalué les hospitalizations toutes causes confondues, les réadmissions toutes causes confondues dans les 30 jours suivant le congé initial, la durée du séjour (en comptant les visites multiples par personne) et les coûts associés à ces admissions. Méthodologie: Nous avons présenté le nombre, le pourcentage, la médiane (25e et 75e percentile) et le taux d'incidence par 1000 années-personnes pour les visites aux urgences et les hospitalizations. Les coûts de santé par individu associés aux visites à l'urgence et aux hospitalizations toutes causes confondues ont été estimés en multipliant la pondération du volume des ressources par le coût pondéré par cas. Résultats: Les patients hémodialysés en center présentaient beaucoup plus de comorbidités (p. Ex. diabète) que la population générale appariée. Au cours d'un suivi médian respectif de 1,8 an (25e et 75e percentile: 0,7 et 3,6 ans) et de 5,2 ans (2,5 et 8,4 ans), 80 % (n=20 309) des patients hémodialysés en center ont visité l'urgence au moins une fois, contre 56 % (n= 56 452) des patients de la population générale appariée. Le taux d'incidence des visites aux urgences, en permettant plusieurs visites par personne, était de 2274 pour 1000 années-personnes (intervalle de confiance à 95% [IC 95%]: 2 263 à 2 286) chez les patients hémodialysés en center, soit presque cinq fois plus élevé que la population générale appariée (471 pour 1000 années-personnes; IC95 %: 469 à 473). Les taux d'admissions à partir de l'urgence et d'hospitalizations toutes causes confondues dans la population de patients hémodialysés en center étaient plus de sept fois plus élevés que dans la population générale appariée (admissions à partir de l'urgence: 786 contre 101 pour 1000 années-personnes; hospitalizations toutes causes confondues: 1056 contre 139 pour 1000 années-personnes). La durée médiane des hospitalizations toutes causes confondues par année-patient était de 4,0 jours (0 et 16,5 jours) chez les patients hémodialysés en center et de 0 jour (0 et 0,5 jour) dans la population générale appariée. Le coût par année-patient des visites à l'urgence chez les patients hémodialysés en center était environ 5,5 fois plus élevé que dans la population générale appariée, tandis que celui des hospitalizations était environ 11 fois plus élevé (visites à l'urgence: 1153 CAD contre 209 CAD; hospitalizations: 21 151 CAD contre 1873 CAD [coûts en dollars canadiens de 2023]). Limites: Généralisabilité externe; impossiblede déterminer si les visites aux urgences et les hospitalizations étaient évitables. Conclusion: Les patients hémodialysés en center sont de grands utilisateurs des soins de santé aigus. Ces résultats améliorent notre compréhension du fardeau de la maladie et des coûts associés à cette utilization dans cette population. Ces résultats soulignent également la nécessité d'améliorer les résultats des soins aigus et peuvent aider à la planification des capacités en matière de soins de santé. D'autres études sont nécessaires pour examiner le risque d'hospitalization après la gestion des comorbidités des patients.

Acute health care use among children during the first 2.5 years of the COVID-19 pandemic in Ontario, Canada: a population-based repeated cross-sectional study.

BACKGROUND: The effects of the decline in health care use at the start of the COVID-19 pandemic on the health of children are unclear. We sought to estimate changes in rates of severe and potentially preventable health outcomes among children during the pandemic. METHODS: We conducted a repeated cross-sectional study of children aged 0-17 years using linked population health administrative and disease registry data from January 2017 through August 2022 in Ontario, Canada. We compared observed rates of emergency department visits and hospital admissions during the pandemic to predicted rates based on the 3 years preceding the pandemic. We evaluated outcomes among children and neonates overall, among children with chronic health conditions and among children with specific diseases sensitive to delays in care. RESULTS: All acute care use for children decreased immediately at the onset of the pandemic, reaching its lowest rate in April 2020 for emergency department visits (adjusted relative rate [RR] 0.28, 95% confidence interval [CI] 0.28-0.29) and hospital admissions (adjusted RR 0.43, 95% CI 0.42-0.44). These decreases were sustained until September 2021 and May 2022, respectively. During the pandemic overall, rates of all-cause mortality, admissions for ambulatory care-sensitive conditions, newborn readmissions or emergency department visits or hospital admissions among children with chronic health conditions did not exceed predicted rates. However, after declining significantly between March and May 2020, new presentations of diabetes mellitus increased significantly during most of 2021 (peak adjusted RR 1.49, 95% CI 1.28-1.74 in July 2021) and much of 2022. Among these children, presentations for diabetic ketoacidosis were significantly higher than expected during the pandemic overall (adjusted RR 1.14, 95% CI 1.00-1.30). We observed similar time trends for new presentations of cancer, but we observed no excess presentations of severe cancer overall (adjusted RR 0.91, 95% CI 0.62-1.34). INTERPRETATION: In the first 30 months of the pandemic, disruptions to care were associated with important delays in new diagnoses of diabetes but not with other acute presentations of select preventable conditions or with mortality. Mitigation strategies in future pandemics or other health system disruptions should include education campaigns around important symptoms in children that require medical attention.

Association of sulfonylureas with the risk of dementia: A population-based cohort study.

BACKGROUND: Sulfonylureas are oral glucose-lowering medications positioned as a second-line therapy for type 2 diabetes. Evidence relating them to cognitive decline has been mixed. The objective was to determine whether sulfonylurea use was associated with a differential risk of dementia compared with dipeptidyl peptidase-4 (DPP4) inhibitor use. METHODS: Using administrative data from residents in Ontario, Canada, adults aged ≥66 years who were new users of a sulfonylurea or a DPP4 inhibitor from June 14, 2011, to March 31, 2021 entered this population-based retrospective cohort study. Dementia was ascertained using a validated algorithm for Alzheimer's disease and related dementias. Propensity-score weighted Cox proportional hazards models were used to obtain adjusted hazard ratios (aHR) and confidence intervals (CI) for time to incident dementia. The observation window started at 1 year after cohort entry to mitigate protopathic bias due to delayed diagnosis. The primary analysis used an intention-to-treat exposure definition. A separate propensity-score weighted analysis was conducted to explore within-class differences in dementia risk among sulfonylurea new users selected from the primary cohort. RESULTS: Among 107,806 DPP4 inhibitor new users and 37,030 sulfonylurea new users, sulfonylureas compared with DPP4 inhibitors were associated with a higher risk of dementia (18.4/1000 person-years; aHR [95% CI] = 1.09 [1.04-1.15]) over a mean follow-up of 4.82 years from cohort entry. Glyburide compared to gliclazide exhibited a higher dementia risk (aHR [95% CI] = 1.17 [1.03-1.32]). CONCLUSION: New use of a sulfonylurea especially glyburide was associated with a higher dementia risk compared with new use of a DPP4 inhibitor in older adults with diabetes.

Association of Sodium-Glucose Cotransporter 2 Inhibitors With Time to Dementia: A Population-Based Cohort Study.

OBJECTIVE: Type 2 diabetes (T2D) increases dementia risk, but clear evidence to recommend interventions that can mitigate that risk remains lacking. This population-based retrospective cohort study aimed to determine whether new use of sodium-glucose cotransporter 2 (SGLT2) inhibitors compared with dipeptidyl peptidase 4 (DPP-4) inhibitors was associated with lower dementia risk. RESEARCH DESIGN AND METHODS: Ontario residents aged ≥66 years who were new users of an SGLT2 inhibitor or a DPP-4 inhibitor from 1 July 2016 to 31 March 2021 entered the cohort. Incident dementia was identified using a validated algorithm for Alzheimer's disease and related dementias. Propensity score-weighted Cox proportional hazards models were used to obtain adjusted hazard ratios (aHR) and CIs for time to incident dementia. To address reverse causality and disease latency, the observation window started at 1-year lag time from cohort entry. The primary analysis followed intention-to-treat exposure definition, and a secondary as-treated analysis was performed. RESULTS: Among 106,903 individuals, SGLT2 inhibitors compared with DPP-4 inhibitors were associated with lower risk of dementia (14.2/1,000 person-years; aHR 0.80 [95% CI 0.71-0.89]) over a mean follow-up of 2.80 years from cohort entry. When stratified by different SGLT2 inhibitors, dapagliflozin exhibited the lowest risk (aHR 0.67 [95% CI 0.53-0.84]), followed by empagliflozin (aHR 0.78 [95% CI 0.69-0.89]), whereas canagliflozin showed no association (aHR 0.96 [95% CI 0.80-1.16]). The as-treated analysis observed a larger association (aHR 0.66 [95% CI 0.57-0.76]) than the intention-to-treat analysis. CONCLUSIONS: SGLT2 inhibitors showed an association with lower dementia risk in older people with T2D. Randomized controlled trials are warranted.

Derivation and External Validation of a Risk Index for Predicting Acute Kidney Injury Requiring Kidney Replacement Therapy After Noncardiac Surgery.

Importance: Severe acute kidney injury (AKI) is a serious postoperative complication. A tool for predicting the risk of AKI requiring kidney replacement therapy (KRT) after major noncardiac surgery might assist with patient counseling and targeted use of measures to reduce this risk. Objective: To derive and validate a predictive model for AKI requiring KRT after major noncardiac surgery. Design, Setting, and Participants: In this prognostic study, 5 risk prediction models were derived and internally validated in a population-based cohort of adults without preexisting kidney failure who underwent noncardiac surgery in Alberta, Canada, between January 1, 2004, and December 31, 2013. The best performing model and corresponding risk index were externally validated in a population-based cohort of adults without preexisting kidney failure who underwent noncardiac surgery in Ontario, Canada, between January 1, 2007, and December 31, 2017. Data analysis was conducted from September 1, 2019, to May 31, 2021. Exposures: Demographic characteristics, surgery type, laboratory measures, and comorbidities before surgery. Main Outcomes and Measures: Acute kidney injury requiring KRT within 14 days after surgery. Discrimination was assessed using the C statistic; calibration was assessed using calibration intercept and slope. Logistic recalibration was used to optimize model calibration in the external validation cohort. Results: The derivation cohort included 92 114 patients (52.2% female; mean [SD] age, 62.3 [18.0] years), and the external validation cohort included 709 086 patients (50.8% female; mean [SD] age, 61.0 [16.0] years). A total of 529 patients (0.6%) developed postoperative AKI requiring KRT in the derivation cohort, and 2956 (0.4%) developed postoperative AKI requiring KRT in the external validation cohort. The following factors were consistently associated with the risk of AKI requiring KRT: younger age (40-69 years: odds ratio [OR], 2.07 [95% CI, 1.69-2.53]; <40 years: OR, 3.73 [95% CI, 2.61-5.33]), male sex (OR, 1.55; 95% CI, 1.28-1.87), surgery type (colorectal: OR, 4.86 [95% CI, 3.28-7.18]; liver or pancreatic: OR, 6.46 [95% CI, 3.85-10.83]; other abdominal: OR, 2.19 [95% CI, 1.66-2.89]; abdominal aortic aneurysm repair: OR, 19.34 [95% CI, 14.31-26.14]; other vascular: OR, 7.30 [95% CI, 5.48-9.73]; thoracic: OR, 3.41 [95% CI, 2.07-5.59]), lower estimated glomerular filtration rate (OR, 0.97; 95% CI, 0.97-0.97 per 1 mL/min/1.73 m2 increase), lower hemoglobin concentration (OR, 0.99; 95% CI, 0.98-0.99 per 0.1 g/dL increase), albuminuria (mild: OR, 1.88 [95% CI, 1.52-2.33]; heavy: OR, 3.74 [95% CI, 2.98-4.69]), history of myocardial infarction (OR, 1.63; 95% CI, 1.32-2.03), and liver disease (mild: OR, 2.32 [95% CI, 1.66-3.24]; moderate or severe: OR, 4.96 [95% CI, 3.58-6.85]). In external validation, a final model including these variables showed excellent discrimination (C statistic, 0.95; 95% CI, 0.95-0.96), with sensitivity of 21.2%, specificity of 99.9%, positive predictive value of 38.1%, and negative predictive value of 99.7% at a predicted risk threshold of 10% or greater. Conclusions and Relevance: The findings suggest that this risk model can predict AKI requiring KRT after noncardiac surgery using routine preoperative data. The model may be feasible for implementation in clinical perioperative risk stratification for severe AKI.

The Role of a Resilient Information Infrastructure in COVID-19 Vaccine Uptake in Ontario.

The COVID-19 pandemic has highlighted the need for a robust and nimble public health data infrastructure. ICES - a government-sponsored, independent, non-profit research institute in Ontario, Canada - functions as a key component of a resilient information infrastructure and an enabler of data co-production, contributing to Ontario's response to the COVID-19 pandemic as part of a learning health system. Linked data on the cumulative incidence of infection and vaccination at the neighbourhood level revealed disparate uptake between areas with low versus high risk of COVID-19. These data were leveraged by the government, service providers, media and the public to inform a more efficient and equitable vaccination strategy.

Use of sodium-glucose cotransporter-2 inhibitors and risk of acute kidney injury in older adults with diabetes: a population-based cohort study.

BACKGROUND: Regulatory agencies warn about the risk of acute kidney injury (AKI) after the initiation of sodium-glucose cotransporter-2 (SGLT2) inhibitors. Our objective was to quantify the 90-day risk of AKI in older adults after initiation of SGLT2 inhibitors in routine clinical practice. METHODS: We conducted a population-based retrospective cohort study in Ontario, Canada, involving adults with diabetes who were aged 66 years or older and who were newly dispensed either an SGLT2 inhibitor or a dipeptidyl peptidase-4 (DPP4) inhibitor in an outpatient setting between 2015 and 2017. We used inverse probability of treatment weighting based on a propensity score to balance the 2 groups on measured baseline characteristics. The primary outcome was 90-day risk of a hospital encounter (i.e., visit to the emergency department or admission to hospital) with AKI, which we defined by a 50% or greater increase in the concentration of serum creatinine from the baseline value or an absolute increase of at least 27 µmol/L after an SGLT2 or DDP4 inhibitor was dispensed. We obtained weighted risk ratios using modified Poisson regression and weighted risk differences using binomial regression. RESULTS: We included 39 094 patients with a median age of 70 (interquartile range 68-74) years in the study. Relative to new use of a DPP4 inhibitor, initiation of a SGLT2 inhibitor was associated with a lower 90-day risk of a hospital encounter with AKI: 216 events in 19 611 patients (1.10%) versus 388 events in 19 483 patients (1.99%); weighted risk ratio 0.79 (95% confidence interval 0.64-0.98). INTERPRETATION: In routine care of older adults, new use of SGLT2 inhibitors compared with use of DPP4 inhibitors was associated with a lower risk of AKI. Together with previous evidence, our findings suggest that regulatory warnings about AKI risk with SGLT2 inhibitors are unwarranted.

Identifying Ontario geographic regions to assess adults who present to hospital with laboratory-defined conditions: a descriptive study.

BACKGROUND: In 2007, an electronic repository called the Ontario Laboratories Information System (OLIS) was introduced to allow health care providers timely access to laboratory test results. Since not all laboratories began submitting their data to OLIS simultaneously, we sought to create a date-dependent table of geographic regions (forward sortation areas [FSAs]) from which people would likely present to a hospital linked to OLIS. METHODS: In this descriptive study, we used administrative data to capture adults in Ontario who presented to the emergency department for any reason from 2007 to 2017. To assess changes over time, we classified all emergency department visits into fiscal quarters. The primary outcome measure was the proportion of people in a given FSA presenting to an emergency department at an OLIS-linked hospital (v. a hospital not linked to OLIS). To be included in the catchment area, at least 90% of all emergency department visits in a given quarter from a given FSA must have occurred at an OLIS-linked hospital. RESULTS: By Dec. 31, 2017, 323 (61.4%) of 526 Ontario FSAs were in the catchment area (a population of about 8.5 million). There were no differences in selected demographic characteristics or comorbidities between people residing within the catchment area of OLIS-linked hospitals and those residing in the catchment area of unlinked hospitals on Dec. 31, 2017. We used the FSA information to construct a date-dependent table of geographic areas likely to have hospital laboratory data available in OLIS for future studies. INTERPRETATION: We identified relevant Ontario geographic regions from which people would likely present to a hospital linked to OLIS. These geographic regions constitute a catchment area that may be used in future studies to capture adults who present to an OLIS-linked hospital with laboratory-defined conditions such as acute kidney injury, hyperkalemia and hyponatremia.

Attitudes and Opinions of Canadian Nephrologists Toward Continuous Quality Improvement Options.

BACKGROUND AND OBJECTIVES: A shift to holding individual physicians accountable for patient outcomes, rather than facilities, is intuitively attractive to policy makers and to the public. We were interested in nephrologists' attitudes to, and awareness of, quality metrics and how nephrologists would view a potential switch from the current model of facility-based quality measurement and reporting to publically available reports at the individual physician level. DESIGN SETTING PARTICIPANTS AND MEASUREMENTS: The study was conducted using a web-based survey instrument (Online Appendix 1). The survey was initially pilot tested on a group of 8 nephrologists from across Canada. The survey was then finalized and e-mailed to 330 nephrologists through the Canadian Society of Nephrology (CSN) e-mail distribution list. The 127 respondents were 80% university based, and 33% were medical/dialysis directors. RESULTS: The response rate was 43%. Results demonstrate that 89% of Canadian nephrologists are engaged in efforts to improve the quality of patient care. A minority of those surveyed (29%) had training in quality improvement. They feel accountable for this and would welcome the inclusion of patient-centered metrics of care quality. Support for public reporting as an effective strategy on an individual nephrologist level was 30%. CONCLUSIONS: Support for public reporting of individual nephrologist performance was low. The care of nephrology patients will be best served by the continued development of a critical mass of physicians trained in patient safety and quality improvement, by focusing on patient-centered metrics of care delivery, and by validating that all proposed new methods are shown to improve patient care and outcomes.

CONTEXTE ET OBJECTIFS DE L'ÉTUDE: Une transition vers l'attribution de la responsabilité des résultats des patients au médecin traitant plutôt qu'à l'établissement de soins de santé est un concept attrayant pour les décideurs et le grand public. Notre objectif d'étude était bipartite: d'abord, nous voulions explorer la perception et la connaissance qu'ont les néphrologues des indicateurs de la qualité des soins; ensuite, nous souhaitions prendre connaissance de l'avis des néphrologues sur un éventuel changement de modèle, lequel évalue actuellement la qualité des soins de manière globale plutôt que pour chaque médecin et enfin, sur l'idée que de tels rapports individuels soient accessibles au public. CONCEPTION ET CADRE DE L'ÉTUDE PARTICIPANTS ET MÉTHODOLOGIE: L'étude a été réalisée à l'aide d'un sondage Web (voir l'annexe 1). Une version provisoire du sondage a d'abord été testée auprès de huit néphrologues de partout au Canada. La version définitive du sondage a été envoyée par courriel à 330 néphrologues figurant sur la liste d'envoi de la Société canadienne de néphrologie (SCN). Le taux de réponse global a été de 43%. Des 127 répondants, la grande majorité (80%) travaillait en milieu universitaire et 33% occupait un poste de directeur médical ou de directeur d'unité de dialyse. RÉSULTATS: Les résultats ont démontré que 89% des néphrologues canadiens s'efforcent déjà d'améliorer les soins prodigués aux patients, et qu'une minorité d'entre eux (29%) ont reçu une formation pertinente. De manière générale, ils se sentent responsables de la qualité des soins et sont réceptifs à l'idée d'inclure des critères d'évaluation plus axés sur les patients. Le taux d'approbation en regard de l'accès libre aux rapports individuels comme une stratégie efficace au plan individuel était de 30%. CONCLUSION: Un faible pourcentage des néphrologues s'est prononcé en faveur de la divulgation publique de rapport faisant état de leur performance individuelle. Les soins prodigués aux patients suivis en néphrologie seront perfectionnés en continuant d'augmenter le nombre de médecins formés en matière d'amélioration de la qualité des soins aux patients et de sécurité, en promouvant des indicateurs de qualité centrés sur les patients, et en vérifiant que toute nouvelle méthode proposée vise foncièrement à améliorer les soins ou les résultats des patients.