Surgery In Ontario Research Articles

Derivation and validation of pragmatic clinical models to predict hospital length of stay after cardiac surgery in Ontario, Canada: a population-based cohort study.

Cardiac surgery is resource intensive and often requires multidisciplinary involvement to facilitate discharge. To facilitate evidence-based resource planning, we derived and validated clinical models to predict postoperative hospital length of stay (LOS). We used linked, population-level databases with information on all Ontario residents and included patients aged 18 years or older who underwent coronary artery bypass grafting, valvular or thoracic aorta surgeries between October 2008 and September 2019. The primary outcome was hospital LOS. The models were derived by using patients who had surgery before Sept. 30, 2016, and validated after that date. To address the rightward skew in LOS data and to identify top-tier resource users, we used logistic regression to derive a model to predict the likelihood of LOS being more than the 98th percentile (> 30 d), and γ regression in the remainder to predict continuous LOS in days. We used backward stepwise variable selection for both models. Among 105 193 patients, 2422 (2.3%) had an LOS of more than 30 days. Factors predicting prolonged LOS included age, female sex, procedure type and urgency, comorbidities including frailty, high-risk acute coronary syndrome, heart failure, reduced left ventricular ejection fraction and psychiatric and pulmonary circulatory disease. The C statistic was 0.92 for the prolonged LOS model and the mean absolute error was 2.4 days for the continuous LOS model. We derived and validated clinical models to identify top-tier resource users and predict continuous LOS with excellent accuracy. Our models could be used to benchmark clinical performance based on expected LOS, rationally allocate resources and support patient-centred operative decision-making.

Complications Following Elective Major Noncardiac Surgery Among Patients With Prior SARS-CoV-2 Infection

There is an urgent need for evidence to inform preoperative risk assessment for the millions of people who have had SARS-CoV-2 infection and are awaiting elective surgery, which is critical to surgical care planning and informed consent. To assess the association of prior SARS-CoV-2 infection with death, major adverse cardiovascular events, and rehospitalization after elective major noncardiac surgery. This population-based cohort study included adults who had received a polymerase chain reaction test for SARS-CoV-2 infection within 6 months prior to elective major noncardiac surgery in Ontario, Canada, between April 2020 and October 2021, with 30 days follow-up. Positive SARS-CoV-2 polymerase chain reaction test result. The main outcome was the composite of death, major adverse cardiovascular events, and all-cause rehospitalization within 30 days after surgery. Of 71 144 patients who underwent elective major noncardiac surgery (median age, 66 years [IQR, 57-73 years]; 59.8% female), 960 had prior SARS-CoV-2 infection (1.3%) and 70 184 had negative test results (98.7%). Prior infection was not associated with the composite risk of death, major adverse cardiovascular events, and rehospitalization within 30 days of elective major noncardiac surgery (5.3% absolute event rate [n = 3770]; 960 patients with a positive test result; adjusted relative risk [aRR], 0.91; 95% CI, 0.68-1.21). There was also no association between prior infection with SARS-CoV-2 and postoperative outcomes when the time between infection and surgery was less than 4 weeks (aRR, 1.15; 95% CI, 0.64-2.09) or less than 7 weeks (aRR, 0.95; 95% CI, 0.56-1.61) and among those who were previously vaccinated (aRR, 0.81; 95% CI, 0.52-1.26). In this study, prior infection with SARS-CoV-2 was not associated with death, major adverse cardiovascular events, or rehospitalization following elective major noncardiac surgery, although low event rates and wide 95% CIs do not preclude a potentially meaningful increase in overall risk.

Rates, Predictive Factors, and Adverse Outcomes of Fusion Surgery for Lumbar Degenerative Disorders in Ontario, Canada, Between 2006 and 2015: A Retrospective Cohort Study

The addition of fusion surgery to the decompression for lumbar degenerative disorders remains controversial. The purpose of this study is to compare the rate and outcome of decompression and fusion versus decompression alone. This population-based retrospective cohort study used several linked administrative databases to identify patients who underwent spinal decompression surgery in Ontario, Canada, from 2006 to 2015. Patients who had previous spine surgery, concurrent lumbar disc replacement, or a diagnosis other than degenerative disc disease were excluded. Adjusted logistic regression was used to assess our outcomes. We identified 33,912 patients, of whom 9748 (28.74%) underwent fusion. Overall, fusion rates increased from 27.66% to 31.33% over the study period (P= 0.025). Factors associated with fusion included: older age, female sex, American Society of Anesthesiologists score ≥3, previous total joint replacement, and surgery by an orthopedic surgeon. Fusion surgery was associated with increased odds of 30-day mortality (odds ratio [OR] 1.77, 95% confidence interval [CI] 1.01-3.09; P= 0.046), 30-day (OR 1.94, 95% CI 1.53-2.46; P < 0.0001) and 90-day reoperation (OR 1.66, 95% CI 1.35-2.05; P < 0.0001), and 30-day readmission (OR 1.23, 95% CI 1.02-1.49; P= 0.027) when adjusting for confounding variables. The odds of suffering a complication after fusion and decompression surgery vs. decompression surgery alone were 4.3-fold greater (95% CI 3.78-5.09; P < 0.0001). As compared with decompression alone, spinal fusion for degenerative lumbar disorders is associated with increased odds of adverse outcomes. These findings highlight the need for spine surgeons to consider carefully their indications for fusion procedures in the setting of degenerative spinal disorders.

Troponin testing after noncardiac surgery: a population-based historical cohort study on variation and factors associated with testing in Ontario.

International practice guidelines make different recommendations for postoperative troponin testing to detect perioperative myocardial infarction and myocardial injury after noncardiac surgery. To gain insights into current testing patterns, we evaluated predictors of routine troponin testing after three commonly performed major noncardiac surgeries. We conducted a population-based historical cohort study of adults having major orthopedic, colorectal, or vascular surgery in Ontario, Canada from 1 January 2010 to 31 December 2017. We used hierarchical logistic regression modelling to assess the association of patient, surgery, and hospital factors with postoperative troponin testing, while accounting for clustering at the hospital level. We characterized hospital-level variation by the intraclass correlation coefficient (ICC), which was adjusted for various characteristics. The cohort included 176,454 eligible patients. Hospital-specific adjusted testing rates ranged from 0-20.1% for orthopedic surgery, 0-43.8% for colorectal surgery, and 19.6-88.0% for vascular surgery. Older age, urgent surgery status, and surgery duration were consistently associated with higher rates of testing for all three surgeries. Higher Revised Cardiac Risk Index scores were associated with higher odds of testing for orthopedic and colorectal surgery, but not for vascular surgery. Even after adjustment, the ICCs were 9.2%, 7.4%, and 24.1% for orthopedic, general, and vascular surgery, respectively. Troponin testing varied substantially across hospitals for selected major noncardiac surgery procedures even after accounting for differences in patient-level cardiac risk factors. Our observations lend support to a more standardized approach for troponin testing after noncardiac surgery.

Derivation and validation of a clinical risk score to predict death among patients awaiting cardiac surgery in Ontario, Canada: a population-based study.

Background:Surgical delay may result in unintended harm to patients needing cardiac surgery, who are at risk for death if their condition is left untreated. Our objective was to derive and internally validate a clinical risk score to predict death among patients awaiting major cardiac surgery.Methods:We used the CorHealth Ontario Registry and linked ICES health administrative databases with information on all Ontario residents to identify patients aged 18 years or more who were referred for isolated coronary artery bypass grafting (CABG), valvular procedures, combined CABG–valvular procedures or thoracic aorta procedures between Oct. 1, 2008, and Sept. 30, 2019. We used a hybrid modelling approach with the random forest method for initial variable selection, followed by backward stepwise logistic regression modelling for clinical interpretability and parsimony. We internally validated the logistic regression model, termed the CardiOttawa Waitlist Mortality Score, using 200 bootstraps.Results:Of the 112 266 patients referred for cardiac surgery, 269 (0.2%) died while awaiting surgery (118/72 366 [0.2%] isolated CABG, 81/24 461 [0.3%] valvular procedures, 63/12 046 [0.5%] combined CABG–valvular procedures and 7/3393 [0.2%] thoracic aorta procedures). Age, sex, surgery type, left main stenosis, Canadian Cardiovascular Society classification, left ventricular ejection fraction, heart failure, atrial fibrillation, dialysis, psychosis and operative priority were predictors of waitlist mortality. The model discriminated (C-statistic 0.76 [optimism-corrected 0.73]). It calibrated well in the overall cohort (Hosmer–Lemeshow p = 0.2) and across surgery types.Interpretation:The CardiOttawa Waitlist Mortality Score is a simple clinical risk model that predicts the likelihood of death while awaiting cardiac surgery. It has the potential to provide data-driven decision support for managing access to cardiac care and preserve system capacity during the COVID-19 pandemic, the recovery period and beyond.

The Impact of COVID-19 on the Surgical Wait Times for Plastic and Reconstructive Surgery in Ontario.

Purpose: The aim of this study was to assess the impact of COVID-19 on surgical wait times for Plastic and Reconstructive Surgery (PRS) in Ontario, Canada. Methods: Ontario's wait time data has fourteen reporting categories for PRS. For each category, the mean wait time for consultation and for surgery were reported. Each category was given a priority ranging from 1 to 4. Two periods, three-month and six-month, were selected and compared to the same calendar months of the previous year. Wait times, surgical volume and percent change to the provincial wait time target were reported and compared to the baseline data. Results: This study reviewed 9563 consults and 15,000 operative cases. There was a 50% reduction in the volume of surgical consults during the study period compared to the baseline period (P = 0.004). The reduction ranged from 46% to 75% based on the reporting category. The volume of surgical cases decreased by 43% during the study period compared to the baseline period (P = 0.005). A statistically significant increase in the mean wait times for surgery was observed, involving priorities 2 to 4 (overall mean = 32 days, P ≤ 0.01). There was a 15% decrease in the percentage of surgeries meeting the provincial target times (P < 0.0001). Conclusion: COVID-19 has caused a significant reduction in the volume of cases performed in the majority of PRS categories with an overall increase in the wait times for consultation and for surgery. Recovery following COVID-19 will require strategies to address the growing volume of cases and wait times for surgery across all PRS categories.

2021 Canadian Surgery Forum: Virtual, online Sept. 21-24, 2021.

# 01. Design and validation of a unique endoscopy simulator using a commercial video game {#article-title-2} Procedural simulation has been shown to enhance early endoscopy training. In this proof of concept study, we aimed to show that a first-person shooter (FPS) video game with a novel in-house

Derivation and validation of predictive indices for 30-day mortality after coronary and valvular surgery in Ontario, Canada.

Background:Coronary artery bypass grafting (CABG) and surgical aortic valve replacement (AVR) are the 2 most common cardiac surgery procedures in North America. We derived and externally validated clinical models to estimate the likelihood of death within 30 days of CABG, AVR or combined CABG + AVR.Methods:We obtained data from the CorHealth Ontario Cardiac Registry and several linked population health administrative databases from Ontario, Canada. We derived multiple logistic regression models from all adult patients who underwent CABG, AVR or combined CABG + AVR from April 2017 to March 2019, and validated them in 2 temporally distinct cohorts (April 2015 to March 2017 and April 2019 to March 2020).Results:The derivation cohorts included 13 435 patients who underwent CABG (30-d mortality 1.73%), 1970 patients who underwent AVR (30-d mortality 1.68%) and 1510 patients who underwent combined CABG + AVR (30-d mortality 3.05%). The final models for predicting 30-day mortality included 15 variables for patients undergoing CABG, 5 variables for patients undergoing AVR and 5 variables for patients undergoing combined CABG + AVR. Model discrimination was excellent for the CABG (c-statistic 0.888, optimism-corrected 0.866) AVR (c-statistic 0.850, optimism-corrected 0.762) and CABG + AVR (c-statistic 0.844, optimism-corrected 0.776) models, with similar results in the validation cohorts.Interpretation:Our models, leveraging readily available, multidimensional data sources, computed accurate risk-adjusted 30-day mortality rates for CABG, AVR and combined CABG + AVR, with discrimination comparable to more complex American and European models. The ability to accurately predict perioperative mortality rates for these procedures will be valuable for quality improvement initiatives across institutions.

Structures, processes and models of care for emergency general surgery in Ontario: a cross-sectional survey.

Background:Emergency general surgery (EGS) patients require urgent surgical evaluation and intervention for various conditions, such as infectious or obstructive diseases of the gastrointestinal tract. We aimed to characterize the structures and processes that are relevant to the delivery of EGS care across Ontario hospitals and to evaluate the availability of critical resources at hospitals with formal EGS models.Methods:Between August 2019 and July 2020, we conducted a cross-sectional survey of Ontario hospitals that offered urgent general surgery (defined as the ability to provide nonelective surgical intervention within 24 to 48 hours of presentation) to adults. People with intimate knowledge of their hospital’s EGS program completed a Web-based or telephone survey characterizing the program’s organizational structure and staffing, operating room availability, interventional radiology and interventional endoscopy availability, intensive care unit availability and staffing, and regional participation. Their responses were compiled and comparisons were made between hospitals with and without formal EGS models of care, as well as between hospitals based on size and academic status.Results:Of the 114 Ontario hospitals identified, 109 responded (95.6% response rate). A third (34.6%; n = 37/107) of hospitals had EGS models of care. Thirty-four of these (91.9%) were large (> 100-bed) institutions that would be likely to have increased resources. However, even for hospitals of similar size, those with EGS models had increased staffing levels compared to those without (clinical associates 17.6% [n = 3/17] v. 10.0% [n = 2/20]; nurse practitioners or physician assistants 27.8% [n = 5/18] v. 14.3% [n = 3/21]). They also had better access to diagnostic and interventional equipment (24/7 access to computed tomography 94.1% [n = 16/17] v. 69.2% [n = 18/26]), interventional radiology (88.9% [n = 16/18] v. 42.3% [n = 11/26]), endoscopy (100% [n = 18/18] v. 69.2% [n = 18/26]) and endoscopic retrograde cholangiopancreatography (77.8% [n = 14/18] v. 42.3% [n = 11/26]), as well as dedicated operating room time (72.2% [n = 13/18] v. 0% [n = 0/25]).Interpretation:The structures and processes available to care for patients requiring EGS in Ontario were highly variable between hospitals. Hospitals with formal EGS models were more likely to have access to key resources.

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

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. To derive and validate a predictive model for AKI requiring KRT after major noncardiac surgery. 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. Demographic characteristics, surgery type, laboratory measures, and comorbidities before surgery. 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. 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. 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.

Survey of Physiotherapy Practice in Ontario Cardiac Surgery Intensive Care Units.

Purpose: This article describes current physiotherapy practice for critically ill adult patients requiring prolonged stays in critical care (>3 d) after complicated cardiac surgery in Ontario. Method: We distributed an electronic, self-administered 52-item survey to 35 critical care physiotherapists who treat adult cardiac surgery patients at 11 cardiac surgical sites. Pilot testing and clinical sensibility testing were conducted beforehand. Participants were sent four email reminders. Results: The response rate was 80% (28/35). The median reported number of cardiac surgeries performed per week was 30 (interquartile range [IQR] 10), with a median number of 14.5 (IQR 4) cardiac surgery beds per site. Typical reported caseloads ranged from 6 to 10 patients per day per therapist, and 93% reported that they had initiated physiotherapy with patients once they were clinically stable in the intensive care unit. Of 28 treatments, range of motion exercises (27; 96.4%), airway clearance techniques (26; 92.9%), and sitting at the edge of the bed (25; 89.3%) were the most common. Intra-aortic balloon pump and extracorporeal membrane oxygenation appeared to limit physiotherapy practice. Use of outcome measures was limited. Conclusions: Physiotherapists provide a variety of interventions to critically ill cardiac surgery patients. Further evaluation of the limited use of outcome measures in the cardiac surgical intensive care unit is warranted.

Long-term follow-up of endometriosis surgery in Ontario: a population-based cohort study

Endometriosis is a chronic gynecological disease affecting approximately 10% of reproductive aged females and leads to decreased quality of life and productivity. Despite effective medical options, many women do require surgery for endometriosis. There is limited literature examining long term outcomes of endometriosis surgery. This study aimed to characterize the long-term outcomes, including recurrence of symptoms, fertility outcomes, and need for reoperation, of patients who underwent surgical management for endometriosis. This was a population-based cohort study in which the universal coverage health database for the province of Ontario, Canada, was used to identify women aged 18 to 50 years who underwent surgery for endometriosis from April 1, 2002, through March 31, 2018. Surgery was classified as diagnostic laparoscopy, conservative or uterine preserving (minor or major, with and without ovarian preservation), or hysterectomy (with and without ovarian preservation). The outcomes were evaluated from 30 days after the index surgery to the end of the study period or at censoring. Cox proportional hazard regression models were used to estimate the hazard ratios between exposures and outcomes following adjustment for confounders. A total of 84,885 women 2,718 (3.2%) diagnostic laparoscopy, 21,594 (25.4%) minor conservative surgery, 28,484 (33.6%); major conservative with ovarian preservation, 2,102 (2.5%) major conservative without ovarian preservation, 21,609 (25.5%) hysterectomy with ovarian preservation, and 8,378 (9.9%) hysterectomy without ovarian preservation) were included in the cohort and followed for a median of 10 years (interquartile range, 6-13 years). In the first postoperative year, women who underwent diagnostic laparoscopy were significantly more likely to require repeat surgery (adjusted hazard ratio, 1.68; 95% confidence interval, 1.51-1.87), whereas those who underwent major conservative surgery were significantly less likely to require repeat surgery (with ovarian preservation: adjusted hazard ratio, 0.44; 95% confidence interval, 0.41-0.48; without ovarian preservation: adjusted hazard ratio, 0.05; 95% confidence interval, 0.03-0.09). Among women who did not receive repeat surgery in the first year, those who underwent a diagnostic laparoscopy (adjusted hazard ratio, 0.85; 95% confidence interval, 0.76-0.95) and major conservative surgery without ovarian preservation were less likely to undergo repeat surgery (adjusted hazard ratio, 0.12; 95% confidence interval, 0.09-0.18) than those who initially had minor surgery. Compared with those who initially underwent minor surgery, patients who underwent other treatment modalities were less likely to undergo a hysterectomy (diagnostic laparoscopy: adjusted hazard ratio, 0.85; 95% confidence interval, 0.75-0.96; major surgery with ovarian preservation: adjusted hazard ratio, 0.60; 95% confidence interval, 0.57-0.64; major surgery without ovarian preservation: adjusted hazard ratio, 0.05; 95% confidence interval, 0.03-0.08). Following minor and major conservative with ovarian preservation surgery, 8,331 (38.6%) and 9,498 (33.3%) of patients sought an infertility consult within 1 year, respectively. By 5 years after the index surgery, 5,290 (29.4%) of patients who had minor conservative surgery and 4,528 (20.7%) of those who had major conservative with ovarian preservation surgery had given birth at least once. Our study suggests that only a few endometriosis patients who undergo hysterectomy surgery require repeat surgery; however, up to 1 in 4 who undergo minor surgery and 1 in 5 who undergo major conservative surgery with ovarian preservation require additional endometriosis surgery. Up to 1 in 3 patients who had uterine sparing endometriosis surgery subsequently sought an infertility assessment. These findings may inform preoperative counseling in terms of recurrence of symptoms, fertility outcomes, and need for reoperation of women seeking surgical management for endometriosis. Future studies should consider the outcomes of patient satisfaction and quality of life based on the current practices for management of endometriosis.

Stress Incontinence Surgery Does Not Cause Pelvic Malignancy: A Population-Based Cohort Study

We sought to determine if stress urinary incontinence surgery (mesh or nonmesh) is associated with the development of pelvic malignancies later in life. We performed a retrospective cohort study between January 1, 2002 and October 31, 2015 of all women in Ontario, Canada without a history of pelvic malignancy who underwent an index stress incontinence surgery. The primary outcome was a composite of any pelvic malignancy (including urological and gynecological cancers) following stress incontinence surgery. Secondarily, we considered each cancer individually. A survival analysis using a Cox proportional-hazards model with a 3-level categorical exposure (mesh surgery, nonmesh surgery, and control) was performed. Patients were followed until death, emigration or the study end (October 31, 2017). Of the women 74,968 underwent stress urinary incontinence surgery during the study period. There were 5,505,576 women in the control group. Over a median followup of 8.5 years (IQR, 5.5-11.9), 587 pelvic malignancies occurred in the surgery group. Women who underwent stress incontinence surgery had a reduced risk of pelvic malignancy independent of surgery type, compared to controls (Wald type 3 p <0.001; mesh HR, 0.68 [95% CI, 0.62-0.76]; p <0.0001; nonmesh HR, 0.37 [95% CI, 0.29-0.46]; p <0.0001). The individual pelvic cancers similarly demonstrated a reduced risk of malignancy following stress incontinence surgery. At a median followup of 8.5 years, women had no increased risk of pelvic malignancy following either mesh or nonmesh stress urinary incontinence surgery in a large population-based cohort.

Disability-free survival after major cardiac surgery: a population-based retrospective cohort study.

Background:Cardiovascular research has traditionally been dedicated to “tombstone” outcomes, with little attention dedicated to the patient’s perspective. We evaluated disability-free survival as a patient-defined outcome after cardiac surgery.Methods:We conducted a retrospective cohort study of patients aged 40 years and older who underwent coronary artery bypass grafting (CABG) or single or multiple valve (aortic, mitral, tricuspid) surgery in Ontario between Oct. 1, 2008, and Dec. 31, 2016. The primary outcome was disability (a composite of stroke, 3 or more nonelective hospital admissions and admission to a long-term care facility) within 1 year after surgery. We assessed the procedure-specific risk of disability using cumulative incidence functions, and the relative effect of covariates on the subdistribution hazard using Fine and Gray models.Results:The study included 72 824 patients. The 1-year incidence of disability and death was 2431 (4.6%) and 1839 (3.5%) for CABG, 677 (6.5%) and 539 (5.2%) for single valve, 118 (9.0%) and 140 (10.7%) for multiple valve, 718 (9.0%) and 730 (9.2%) for CABG and single valve, and 87 (13.1%) and 94 (14.1%) for CABG and multiple valve surgery, respectively. With CABG as the reference group, the adjusted hazard ratios for disability were 1.34 (95% confidence interval [CI] 1.21–1.48) after single valve, 1.43 (95% CI 1.18–1.75) after multiple valve, 1.38 (95% CI 1.26–1.51) after CABG and single valve, and 1.78 (95% CI 1.43–2.23) after CABG and multiple valve surgery. Combined CABG and multiple valve surgery, heart failure, creatinine 180 μmol/L or greater, alcohol use disorder, dementia and depression were independent risk factors for disability.Interpretation:The cumulative incidence of disability was lowest after CABG and highest after combined CABG and multiple valve surgery. Our findings point to a need for models that predict personalized disability risk to enable better patient-centred care.

Temporal trends in knee arthroscopy surgery in Ontario, Canada, from 2004 to 2018: the influence of new evidence on changes in practice

Temporal trends in knee arthroscopy surgery in Ontario, Canada, from 2004 to 2018: the influence of new evidence on changes in practice

Surgical Outcomes among Focused versus Diversified Cataract Surgeons

Narrowly focused surgical practice has become increasingly common in ophthalmology and may have an effect on surgical outcomes. Previous research evaluating the influence of surgical focus on cataract surgical outcomes has been lacking. This study aimed to evaluate whether surgeons' exclusive surgical focus on cataract surgery influences the risk of cataract surgical adverse events. Population-based cohort study. All patients 66 years of age or older undergoing cataract surgery in Ontario, Canada, between January 1, 2002, and December 31,2013. Outcomes of isolated cataract surgery performed by exclusive cataract surgeons (no other types of surgery performed), moderately diversified cataract surgeons (1%-50% noncataract procedures), and highly diversified cataract surgeons (>50% noncataract procedures) were evaluated using linked healthcare databases and controlling for patient-, surgeon-, and institution-level covariates. Surgeon-level covariates included both surgeon experience and surgical volume. Composite outcome incorporating 4 adverse events: posterior capsule rupture, dropped lens fragments, retinal detachment, and suspected endophthalmitis. The study included 1 101 864 cataract operations. Patients had a median age of 76 years, and 60.2% were female. Patients treated by the 3 groups of surgeons were similar at baseline. Adverse events occurred in 0.73%, 0.78%, and 2.31% of cases performed by exclusive cataract surgeons, moderately diversified surgeons, and highly diversified surgeons, respectively. The risk of cataract surgical adverse events for patients operated on by moderately diversified surgeons was not different than for patients operated on by exclusive cataract surgeons (odds ratio [OR], 1.08; 95% confidence interval [CI], 1.00-1.18). Patients operated on by highly diversified surgeons had a higher risk of adverse events than patients operated on by exclusive cataract surgeons (OR, 1.52; 95% CI, 1.09-2.14). This resulted in an absolute risk difference of 0.016 (95% CI, 0.012-0.020) and a number needed to harm of 64 (95% CI, 50-87). Exclusive surgical focus did not affect the safety of cataract surgery when compared with moderate levels of surgical diversification. The risk of cataract surgical adverse events was higher among surgeons whose practice was dedicated mainly to noncataract surgery.

Short-term outcomes of endometriosis surgery in Ontario: A population-based cohort study.

Our objective was to compare the short-term outcomes by type of surgical management of endometriosis in Ontario, Canada and to characterize the population of women undergoing surgical management of endometriosis. We conducted a population-based cohort study including women aged 18-50years undergoing same-day or inpatient surgery for endometriosis from 1 April 2002 through 31 March 2018. Surgery was classified as minimally invasive hysterectomy (MIH), total abdominal hysterectomy (TAH) or minor or major conservative (uterus-preserving) surgery. Outcomes examined included length of stay, intraoperative complications, postoperative complications, emergency department visits, ambulatory care visits, and readmission. We estimated the relative risk of these outcomes in minor, major conservative surgery and TAH vs MIH adjusted for age, income quintile, parity, and comorbidities. A total of 85605 patients underwent surgery, 12.9% MIH, 22.1% TAH, 36.3% major conservative, and 28.6% minor conservative. The mean age at index surgery was 37.6±7.7years. Before surgery, 70.6% of patients had visited a physician for pain at least once (64.7% MIH, 69.5% TAH, 71.1% major conservative and 73.4% minor conservative) and 23.5% of patients had sought infertility consultation (5.7% MIH, 6.6% TAH, 29.3% major conservative and 37.1% minor conservative). The overall risk of intraoperative and postoperative complications was 1.5% and 4.7%, respectively. In adjusted models, compared with those undergoing minor conservative surgery, those having major conservative surgery were 1.77 (95% CI 1.49-2.11) times as likely to experience an intraoperative complication, those having MIH and TAH were 2.55 (95% CI 2.08-3.13) and 2.34 (95% CI 1.93-2.82) times as likely to do so, respectively. Similarly, compared with those undergoing minor conservative surgery, those having major conservative surgery were 2.60 (95% CI 2.30, 2.93) times as likely to experience any postoperative complication, and those having MIH and TAH were 4.69 (95% CI 4.11-5.36) and 5.38 (95% CI 4.76-6.09) times as likely to do so, respectively. Approximately one-third of patients undergoing surgical management for endometriosis in Ontario between 2002 and 2018 had a hysterectomy. Overall, complications following surgery were low, and dependent on extent of surgery. These results should help to inform preoperative counseling for patients and health policy development for providers.

Abstract 14288: Substantial Hospital-level Variation in Troponin Testing After Non-cardiac Surgery

Introduction: There is an increasing emphasis in detecting postoperative myocardial infarction (PMI) using routine troponin testing after non-cardiac surgery. However, clinical practice guidelines vary considerably in their recommendations. We conducted a population-based cohort study in Ontario, Canada to assess the degree of hospital-level variation associated with troponin testing after three commonly performed surgeries. Methods: We conducted a retrospective cohort study of adults (40-105 y) undergoing major orthopedic, colorectal, or vascular surgery in Ontario, Canada from January 1, 2010 to December 31, 2017. Hierarchical logistic regression modeling was used to model the association of patient, surgery, and hospital factors with postoperative troponin testing, while accounting for clustering at the hospital level. Results: We identified 176,454 eligible patients. Canadian Cardiovascular Society guidelines recommended troponin testing for 73.5%, 90.8% and 95.6% of orthopedic, colorectal, and vascular surgery patients respectively, but only 6.7%, 16.6%, and 50.2% were actually tested. Inter hospital variation in testing rates was considerable for the three surgeries (Figure; 0-33%, 0-38% and 18-84%). Even after risk-adjustment, the median odds ratio for testing across hospitals was still 1.74, 1.63, and 2.65 for orthopedic, colorectal, and vascular surgery, respectively. This corresponded to intraclass correlation coefficients of 9.3%, 7.4%, and 24.2% respectively. Conclusion: Despite strong recommendations by Canadian guidelines for troponin testing after non-cardiac surgery, testing rates were low overall and varied significantly across hospitals.

Derivation and Validation of a Clinical Model to Predict Intensive Care Unit Length of Stay After Cardiac Surgery.

BackgroundAcross the globe, elective surgeries have been postponed to limit infectious exposure and preserve hospital capacity for coronavirus disease 2019 (COVID‐19). However, the ramp down in cardiac surgery volumes may result in unintended harm to patients who are at high risk of mortality if their conditions are left untreated. To help optimize triage decisions, we derived and ambispectively validated a clinical score to predict intensive care unit length of stay after cardiac surgery.Methods and ResultsFollowing ethics approval, we derived and performed multicenter valida tion of clinical models to predict the likelihood of short (≤2 days) and prolonged intensive care unit length of stay (≥7 days) in patients aged ≥18 years, who underwent coronary artery bypass grafting and/or aortic, mitral, and tricuspid value surgery in Ontario, Canada. Multivariable logistic regression with backward variable selection was used, along with clinical judgment, in the modeling process. For the model that predicted short intensive care unit stay, the c‐statistic was 0.78 in the derivation cohort and 0.71 in the validation cohort. For the model that predicted prolonged stay, c‐statistic was 0.85 in the derivation and 0.78 in the validation cohort. The models, together termed the CardiOttawa LOS Score, demonstrated a high degree of accuracy during prospective testing.ConclusionsClinical judgment alone has been shown to be inaccurate in predicting postoperative intensive care unit length of stay. The CardiOttawa LOS Score performed well in prospective validation and will complement the clinician's gestalt in making more efficient resource allocation during the COVID‐19 period and beyond.

Catquest-9SF questionnaire and eCAPS: Validation in a Canadian population.

BackgroundVisual acuity alone has limitations in assessing a patient’s appropriateness and prioritization for cataract surgery. Several tools, including the Catquest-9SF questionnaire and the electronic cataract appropriateness and priority system (eCAPS) have been developed to evaluate patients–reported visual function as related to day-to-day tasks. The aim of this study was to validate Catquest-9SF and eCAPS in a Canadian population and propose a shorter version of each, in an attempt to extend their applicability in clinical practice.MethodsThe English translation of the Swedish Catquest-9SF and eCAPS were self-administered separately in pre-operative patients in tertiary care in Peel region, Ontario. Rasch analysis was used to validate both scales and assess their psychometric properties, such as category threshold order, item fit, unidimensionality, precision, targeting, and differential item functioning.ResultsA total of 313 cataract patients (mean age = 69.1, 56.5% female) completed the Catquest-9SF and eCAPS. Catquest-9SF had ordered response thresholds, adequate precision (person separation index = 2.09, person reliability = 0.81), unidimensionality and no misfits (infit range 0.75–1.35, outfit range 0.83–1.36). There mean for patients was equal to -1.43 (lower than the mean for items which is set automatically at zero), meaning that tasks were relatively easy for respondent ability. eCAPS had 3 items that misfit the Rasch model and were excluded (infit range 0.82–1.30, outfit range 0.75–1.36). Precision was inadequate (person separation index = 0.19, person reliability = 0.04). 78.8% of subjects scored≤9 (answered that they had no issues for most questions).ConclusionsCatquest-9SF demonstrated good psychometric properties and is suitable for assessing visual function of care-seeking patients referred for cataract surgery in Ontario, Canada. There was some mistargeting, suggesting that the tasks were relatively easy to perform, which is consistent with previous research. On the contrary, eCAPS is not sensitive in differentiating patients who had impaired visual functioning.