Incidence of Total Knee Arthroplasty After Arthroscopic Surgery for Knee Osteoarthritis: A Secondary Analysis of a Randomized Clinical Trial.

Importance: It is unclear whether arthroscopic resection of degenerative knee tissues among patients with osteoarthritis (OA) of the knee delays or hastens total knee arthroplasty (TKA); opposite findings have been reported. Objective: To compare the long-term incidence of TKA in patients with OA of the knee after nonoperative management with or without additional arthroscopic surgery. Design, Setting, and Participants: In this ad hoc secondary analysis of a single-center, assessor-blinded randomized clinical trial performed from January 1, 1999, to August 31, 2007, 178 patients were followed up through March 31, 2019. Participants included adults diagnosed with OA of the knee referred for potential arthroscopic surgery in a tertiary care center specializing in orthopedics in London, Ontario, Canada. All participants from the original randomized clinical trial were included. Data were analyzed from June 1, 2021, to October 20, 2022. Exposures: Arthroscopic surgery (resection or debridement of degenerative tears of the menisci, fragments of articular cartilage, or chondral flaps and osteophytes that prevented full extension) plus nonoperative management (physical therapy plus medications as required) compared with nonoperative management only (control). Main Outcomes and Measures: Total knee arthroplasty was identified by linking the randomized trial data with prospectively collected Canadian health administrative datasets where participants were followed up for a maximum of 20 years. Multivariable Cox proportional hazards regression models were used to compare the incidence of TKA between intervention groups. Results: A total of 178 of 277 eligible patients (64.3%; 112 [62.9%] female; mean [SD] age, 59.0 [10.0] years) were included. The mean (SD) body mass index was 31.0 (6.5). With a median follow-up of 13.8 (IQR, 8.4-16.8) years, 31 of 92 patients (33.7%) in the arthroscopic surgery group vs 36 of 86 (41.9%) in the control group underwent TKA (adjusted hazard ratio [HR], 0.85 [95% CI, 0.52-1.40]). Results were similar when accounting for crossovers to arthroscopic surgery (13 of 86 [15.1%]) during follow-up (HR, 0.88 [95% CI, 0.53-1.44]). Within 5 years, the cumulative incidence was 10.2% vs 9.3% in the arthroscopic surgery group and control group, respectively (time-stratified HR for 0-5 years, 1.06 [95% CI, 0.41-2.75]); within 10 years, the cumulative incidence was 23.3% vs 21.4%, respectively (time-stratified HR for 5-10 years, 1.06 [95% CI, 0.45-2.51]). Sensitivity analyses yielded consistent results. Conclusions and Relevance: In this secondary analysis of a randomized clinical trial of arthroscopic surgery for patients with OA of the knee, a statistically significant association with delaying or hastening TKA was not identified. Approximately 80% of patients did not undergo TKA within 10 years of nonoperative management with or without additional knee arthroscopic surgery. Trial Registration: ClinicalTrials.gov Identifier: NCT00158431.

Epilepsy Surgery in Adult Stroke Survivors with New-Onset Drug-Resistant Epilepsy.

BACKGROUND: Despite its effectiveness, surgery for drug-resistant epilepsy is underutilized. However, whether epilepsy surgery is also underutilized among patients with stroke-related drug-resistant epilepsy is unclear. Therefore, our objectives were to estimate the rates of epilepsy surgery assessment and receipt among patients with stroke-related drug-resistant epilepsy and to identify factors associated with these outcomes. METHODS: We used linked health administrative databases to conduct a population-based retrospective cohort study of adult Ontario, Canada residents discharged from an Ontario acute care institution following the treatment of a stroke between January 1, 1997, and December 31, 2020, without prior evidence of seizures. We excluded patients who did not subsequently develop drug-resistant epilepsy and those with other epilepsy risk factors. We estimated the rates of epilepsy surgery assessment and receipt by March 31, 2021. We planned to use Fine-Gray subdistribution hazard models to identify covariates independently associated with our outcomes, controlling for the competing risk of death. RESULTS: We identified 265,081 patients who survived until discharge following inpatient stroke treatment, 1,902 (0.7%) of whom subsequently developed drug-resistant epilepsy (805 women; mean age: 67.0 ± 13.1 years). Fewer than six (≤0.3%) of these patients were assessed for or received epilepsy surgery before the end of follow-up (≤55.5 per 100,000 person-years). Given that few outcomes were identified, we could not proceed with the multivariable analyses. CONCLUSIONS: Patients with stroke-related drug-resistant epilepsy are infrequently considered for epilepsy surgery that could reduce morbidity and mortality.

Epilepsy Risk Following Bariatric Surgery for Weight Loss.

BACKGROUND AND OBJECTIVES: A previous study reported finding that epilepsy risk is elevated after bariatric surgery for weight loss; however, this association has not been adequately explored. Our objectives were to (1) estimate the risk of epilepsy after bariatric surgery for weight loss relative to a nonsurgical cohort of patients with an obesity diagnosis and (2) identify epilepsy risk factors among bariatric surgery recipients. METHODS: We conducted a population-based retrospective cohort study using linked health administrative databases in Ontario, Canada. Participants were accrued between July 1, 2010, and December 31, 2016, and followed until December 31, 2019. All Ontario residents aged 18 years and older who had bariatric surgery during the accrual period were eligible for inclusion in our exposed cohort. Patients hospitalized with a diagnosis of obesity and who did not have bariatric surgery during the accrual period were eligible for inclusion in our unexposed cohort. We excluded patients with a history of seizures, epilepsy, various seizure or epilepsy risk factors, psychiatric disorders, or drug or alcohol abuse/dependence. In our primary analysis, we used inverse probability of treatment weighting to control for confounding. A marginal Cox proportional hazards model was then used to estimate the risk of epilepsy associated with bariatric surgery. A Cox model was also used to identify epilepsy risk factors among exposed participants. RESULTS: The final sample included 16,958 exposed participants and 622,514 unexposed participants. After inverse probability of treatment weighting, the estimated rates of epilepsy were 50.1 and 34.1 per 100,000 person-years among those who did and did not have bariatric surgery, respectively. The hazard ratio for developing epilepsy after bariatric surgery was 1.45 (95% CI = 1.35, 1.56). Among participants who received bariatric surgery, stroke during follow-up increased epilepsy risk (HR = 14.03, 95% CI = 4.26, 46.25). DISCUSSION: In this study, we found that patients with a history of bariatric surgery were at increased risk of developing epilepsy. These findings suggest that epilepsy is a long-term risk associated with bariatric surgery for weight loss.

The association between endocrine therapy use and osteoporotic fracture among post-menopausal women treated for early-stage breast cancer in Ontario, Canada.

BACKGROUND: The use of endocrine therapy for early-stage breast cancer, particularly aromatase inhibitor therapy has been associated with an increased risk of osteoporosis and fracture in clinical trials. We sought to validate this observation in real-world practice. METHODS: We used health administrative data collected from post-menopausal women (aged ≥66 years) who were diagnosed with breast cancer and started on adjuvant endocrine therapy from 2005 to 2012. Patients were classified by use of either an aromatase inhibitor or tamoxifen and followed until 2017 for a new diagnosis of an osteoporotic fracture. A multivariable analysis using a Cox proportional hazards model was adjusting for age, medical co-morbidities, medication use and duration of endocrine therapy. RESULTS: We identified 12,077 patients of whom 73% were treated with an aromatase inhibitor as compared to 27% with tamoxifen. Our multivariable analysis did not demonstrate any significant difference in the rate of osteoporotic fracture between patients treated with an aromatase inhibitor when compared with tamoxifen [Hazard ratio (HR) = 1.09; 95% confidence interval (CI) = 0.96-1.23, p-value = 0.18]. The 5-year rate of osteoporotic fracture for patients treated with either an aromatase inhibitor or tamoxifen was 7.5% and 6.9%, respectively. A completed sensitivity analysis did observe a decreased risk of fracture associated with tamoxifen usage over time. CONCLUSION: We could not detect a significant difference in the rate of osteoporotic fracture among patients treated with an aromatase inhibitor versus tamoxifen. Nonetheless, the risk with tamoxifen was numerically lower and significantly decreased when accounting for total duration of endocrine therapy.

Childhood food insecurity and incident asthma: A population-based cohort study of children in Ontario, Canada.

BACKGROUND: Childhood food insecurity has been associated with prevalent asthma in cross-sectional studies. Little is known about the relationship between food insecurity and incident asthma. METHODS: We used administrative databases linked with the Canadian Community Health Survey, to conduct a retrospective cohort study of children <18 years in Ontario, Canada. Children without a previous diagnosis of asthma who had a household response to the Household Food Security Survey Module (HFSSM) were followed until March 31, 2018 for new asthma diagnoses using a validated administrative coding algorithm. We used multivariable Cox proportional hazard models to examine the association between food insecurity and incident asthma, and adjusted models sequentially for clinical and clinical/socioeconomic risk factors. As additional analyses, we examined associations by HFSSM respondent type, severity of food insecurity, and age of asthma diagnosis. Moreover, we assessed for interaction between food security and child's sex, household smoking status, and maternal asthma on the risk of incident asthma. RESULTS: Among the 27,746 included children, 5.1% lived in food insecure households. Over a median of 8.34 years, the incidence of asthma was 7.33/1000 person-years (PY) among food insecure children and 5.91/1000 PY among food secure children (unadjusted hazard ratio [HR] 1.24, 95% CI 1.00 to 1.54, p = 0.051). In adjusted analyses associations were similar (HR 1.16, 95% CI 0.91 to 1.47, p = 0.24 adjusted for clinical risk factors, HR 1.24, 95% CI 0.97 to 1.60, p = 0.09 adjusted for clinical/socioeconomic factors). Associations did not qualitatively change by HFSSM respondent type, severity of food insecurity, and age of asthma diagnosis. There was no evidence of interaction in our models. CONCLUSIONS: Food insecure children have numerous medical and social challenges. However, in this large population-based study, we did not observe that childhood food insecurity was associated with an increased risk of incident asthma when adjusted for important clinical and socioeconomic confounders.

Opioid Prescribing Practices for Women Undergoing Elective Gynecologic Surgery.

STUDY OBJECTIVE: To describe the opioid prescribing practices in opioid-naive women undergoing elective gynecologic surgery for benign indications and identify risk factors associated with increased perioperative opioid use. We also explored factors associated with new persistent opioid use in women with perioperative opioid use. DESIGN: Retrospective, population-based cohort study. SETTING: We used linked administrative data from a government-administered single-payer provincial healthcare system in Canada. This study was undertaken at ICES, a not-for-profit research institute in Ontario, Canada. PATIENTS: We followed opioid-naive adult women who underwent benign elective gynecologic surgery between 2013 and 2018. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The primary outcome was perioperative opioid use defined as ≥1 opioid prescription from 30 days before to 14 days after surgery. New persistent opioid use after gynecologic surgery was defined as having filled 1 or more opioid prescriptions between 91 days and 180 days postoperatively. Multivariable log-linear regression analyses were employed to adjust for clinical and demographic data. Of the 132 506 patients included in our cohort, most (74.3%) underwent minor gynecologic procedures. Perioperative opioid use was documented in 27 763 (21.0%) patients, and there was a significant decreasing trend (p <.001) in the proportion of patients with perioperative opioid use from 21.8% in 2013 to 18.5% in 2018. Factors associated with increased perioperative opioid use included younger age; higher income quintile; urban dwellers; and diagnosis of infertility, endometriosis, or adnexal mass. Perioperative opioid use was an independent risk factor for persistent use (adjusted relative risk 1.40; 95% confidence interval, 1.13-1.72) and for every 65 patients prescribed opioids associated with gynecologic surgery, one developed new persistent opioid use. The highest risk factor for developing persistent use was filling a high-dose opioid prescription (adjusted relative risk5th quintileOME 2.33; 95% confidence interval, 1.83-2.96). CONCLUSION: One in 5 women who undergo a gynecologic procedure has a new exposure to opioids. For every 65 patients who fill an opioid prescription after their gynecologic surgery, one will experience prolonged opioid use.

Medical use of cocaine and perioperative morbidity following sinonasal surgery-A population study.

BACKGROUND: Topical cocaine is favoured by many surgeons for sinonasal surgery due to its superior vasoconstrictive and anesthetic properties. However, historical reports suggesting cocaine is associated with an increased risk of cardiac events have led many surgeons to turn to alternative topical medications. The objective of this study was to determine whether cocaine use during sinonasal surgery is associated with an increased risk of perioperative cardiac events and death. METHODS: We conducted a population-based analysis of patients undergoing sinonasal surgery from 2009-2016 using linked administrative health care data sets in Ontario, Canada. We compared patients treated at institutions that primarily use topical cocaine (exposed group) to those treated at institutions that do not use cocaine (unexposed group). Our primary outcome was a composite of major cardiac events or all-cause mortality within 48 hours of surgery. Due to low event rates, the outcome was compared using a Fisher's exact test. RESULTS: Of 10,549 patients who were included in the study, 27.4% were treated at an institution that uses topical cocaine. The rate of the composite of perioperative major cardiac event or all-cause mortality within 48 hours of surgery in the exposed and unexposed groups was, ≤0.2% and 0 (p-value>0.05), respectively. CONCLUSIONS: In this large real-world cohort of patients undergoing sinonasal surgery, there does not appear to be any significant increased risk of morbidity or mortality associated with cocaine use. These findings have important implications for surgeons performing this procedure.

The association between endocrine therapy use and dementia among post-menopausal women treated for early-stage breast cancer in Ontario, Canada.

PURPOSE: The association between endocrine therapy and risk of dementia remains uncertain. We investigated the association between adjuvant endocrine therapy for breast cancer and risk of developing dementia in a real-world, population-based study. METHODS: We used health administrative data collected from post-menopausal women (aged ≥66 years) who were diagnosed with breast cancer and started on adjuvant endocrine therapy from 2005 to 2012 with follow-up until 2017. Patients were classified by the use of either an aromatase inhibitor or tamoxifen and followed to estimate the unadjusted cumulative incidence of developing dementia. A multivariable Cox proportional hazards model was created adjusting for age, income quintile, medical co-morbidities, and duration of endocrine therapy. RESULTS: We identified 12,077 patients of whom 73% were treated with an aromatase inhibitor and 27% with tamoxifen. Our multivariable analysis showed a lower rate of dementia in patients treated with an aromatase inhibitor as compared to tamoxifen [Hazard ratio (HR) = 0.88, 95% confidence interval (CI): 0.78-0.98, p-value = .02) at a median follow-up of 5.9 years. The 5-year dementia rate among patient treated with either an aromatase inhibitor or tamoxifen was 7.4% and 9.2% respectively. Older age, previous history of ischemic heart disease, diabetes, hypertension and history of stroke were all significantly associated with the development of dementia. CONCLUSION: Aromatase inhibitor therapy was associated with a decreased incidence of dementia as compared to treatment with tamoxifen among post-menopausal women with early stage breast cancer. Further prospective studies with longer-term follow-up investigating the neurocognitive effects of endocrine therapy are warranted.

Disparities in Deep Brain Stimulation Use for Parkinson's Disease in Ontario, Canada.

OBJECTIVE: To examine whether sociodemographic characteristics and health care utilization are associated with receiving deep brain stimulation (DBS) surgery for Parkinson's disease (PD) in Ontario, Canada. METHODS: Using health administrative data, we identified a cohort of individuals aged 40 years or older diagnosed with incident PD between 1995 and 2009. A case-control study was used to examine whether select factors were associated with DBS for PD. Patients were classified as cases if they underwent DBS surgery at any point 1-year after cohort entry until December 31, 2016. Conditional logistic regression modeling was used to estimate the adjusted odds of DBS surgery for sociodemographic and health care utilization indicators. RESULTS: A total of 46,237 individuals with PD were identified, with 543 (1.2%) receiving DBS surgery. Individuals residing in northern Ontario were more likely than southern patients to receive DBS surgery [adjusted odds ratio (AOR) = 2.23, 95% confidence interval (CI) = 1.15-4.34]; however, regional variations were not observed after accounting for medication use among older adults (AOR = 1.04, 95% CI = 0.26-4.21). Patients living in neighborhoods with the highest concentration of visible minorities were less likely to receive DBS surgery compared to patients living in predominantly white neighborhoods (AOR = 0.27, 95% CI = 0.16-0.46). Regular neurologist care and use of multiple PD medications were positively associated with DBS surgery. CONCLUSIONS: Variations in use of DBS may reflect differences in access to care, specialist referral pathways, health-seeking behavior, or need for DBS. Future studies are needed to understand drivers of potential disparities in DBS use.

Factors associated with endocrine therapy adherence among post-menopausal women treated for early-stage breast cancer in Ontario, Canada.

PURPOSE: Adherence to adjuvant endocrine therapy among post-menopausal breast cancer patients is an important survivorship care issue. We explored factors associated with endocrine therapy adherence and survival in a large real-world population-based study. METHODS: We used health administrative databases to follow women (aged ≥ 66 years) who were diagnosed with breast cancer and started on adjuvant endocrine therapy from 2005 to 2010. Adherence was measured by medical possession ratio (MPR) and characterized as low (< 39% MPR), intermediate (40-79% MPR), or high (≥ 80% MPR) over a 5-year period. We investigated factors associated with adherence using a multinomial logistic regression model. Factors associated with all-cause mortality (5 years after starting endocrine therapy) were investigated using a multivariable Cox proportional hazards model. RESULTS: We identified 5692 eligible patients starting adjuvant endocrine therapy who had low, intermediate, and high adherence rates of 13% (n = 749), 13% (n = 733), and 74% (n = 4210), respectively. Lower rates of adherence were associated with increased age [low vs. high adherence: odds ratio (OR) 1.03, 95% CI 1.02-1.05 (per year); intermediate vs. high adherence: OR 1.02, 95% CI 1.01-1.04 (per year)]. High adherence was associated with previous use of adjuvant chemotherapy (low versus high adherence OR 0.42, 95% CI 0.30-0.59) and short-term follow-up with a medical oncologist within 4 months of starting endocrine therapy (low versus high adherence OR 0.83, 95% CI 0.69-0.99). Unadjusted analysis showed increased survival among patients with high endocrine therapy adherence. However, an independent association was no longer clearly detected after controlling for confounders. CONCLUSION: Interventions to improve adjuvant endocrine therapy adherence are warranted. Non-adherence may be a more significant issue among elderly patients. Short-term follow-up visit by a patient's medical oncologist after starting endocrine therapy may help to improve compliance.

Declining hospitalisation and surgical intervention rates in patients with Crohn's disease: a population-based cohort.

BACKGROUND: Lifetime risk of surgery in patients with Crohn's disease remains high. AIM: To assess population-level markers of Crohn's disease (CD) in the era of biological therapy. METHODS: Population-based cohort study using administrative data from Ontario, Canada including 45 235 prevalent patients in the Ontario Crohn's and Colitis Cohort (OCCC) from 1 April 2003 to 31 March 2014. RESULTS: CD-related hospitalisations declined 32.4% from 2003 to 2014 from 154/1000 (95% confidence interval (CI) [150, 159]) patients to 104/1000 (95% CI [101, 107]) (P < .001). There was a 39.6% decline in in-patient surgeries from 53/1000 (95% CI [50, 55]) to 32/1000 (95% CI [30, 34]) from 2003 to 2014 (P < .001). In-patient surgeries were mostly bowel resections. Out-patient surgeries increased from 8/1000 (95% CI [7, 9]) patients to 12/1000 (95% CI [10, 13]) (P < .001). Out-patient surgeries were largely related to fistulas and perianal disease and for stricture dilations/stricturoplasty. CD-related emergency department (ED) visits declined 28.4% from 141/1000 (95% CI [137, 146]) cases to 101/1000 (95% CI [99, 104]) from 2003 to 2014 (P < .001). Over the same time, patients receiving government drug benefits received infliximab or adalimumab at a combined rate of 2.2% in 2003 which increased to 18.8% of eligible patients by 2014. CONCLUSIONS: Rates of hospitalisations, ED visits and in-patient surgeries markedly declined in Ontario over the study period, while rates of biologic medication use increased markedly for those receiving public drug benefits.

Risks of preoperative anemia in women undergoing elective hysterectomy and myomectomy.

BACKGROUND: Hysterectomy is one of the most common surgeries performed worldwide. Identification of modifiable risk factors for complications or readmissions could lead to targeted interventions to improve patient care and reduce health care costs. Preoperative anemia has been identified as a risk factor for adverse postoperative outcomes following noncardiac surgery. However, studies have not focused on young and healthy surgical populations, such as women undergoing gynecologic surgery for benign indications. OBJECTIVE: The purpose of this study was to evaluate whether preoperative anemia in women undergoing elective hysterectomy or myomectomy for benign indications was associated with increased 30 day postoperative morbidity and mortality. STUDY DESIGN: In this retrospective, population-based cohort study, we followed up adult women (≥18 years of age) who underwent elective hysterectomy or myomectomy (laparoscopic/laparotomy) between the years 2013 and 2015 for benign indications in Ontario, Canada. We used linked administrative data from a government-administered, single-payer provincial health care system using Canadian Classification of Health Interventions intervention codes, International Classification of Diseases, 10th revision, diagnostic codes, physician billing codes, and laboratory data from both community and hospital laboratories across the province. Our exposure of interest was preoperative anemia, defined as a hemoglobin value <12 g/dL on the complete blood count measured closest to the date of surgery. Our primary outcome was the composite of 30 day postoperative morbidity and mortality. Secondary outcomes were 5 individual components of the primary outcome: death, transfusion, surgical site infection, venothromboembolism, and return to the hospital within 30 days. To adjust for confounding, we generated a propensity score using a multiple logistic regression model in which the presence of anemia was regressed on all baseline characteristics. We matched anemic to nonanemic patients on the logit of the propensity score. Using an unadjusted log-binomial model estimated using generalized estimating equations to account for the matched pairs, we calculated the relative risk, 95% confidence intervals, and P values to evaluate the effect of anemia on outcomes. RESULTS: Of the 16,218 women in the cohort, 3664 (22.6%) had anemia. After propensity matching, standardized differences in all baseline characteristics (n = 3261 per group) were <0.10. In the matched cohort, the primary outcome (death, complications, or readmission) occurred in 41.2% of anemic patients and 36.2% of nonanemic patients (relative risk, 1.14, 95% confidence interval, 1.07-1.21, P < .0001; absolute risk reduction, 5.03%, 95% confidence interval, 2.70-7.36; (number needed to harm = 20). The risk of transfusion was significantly higher in anemic patients (relative risk, 3.25, 95% confidence interval, 2.67-3.95, P < .0001; absolute risk reduction, 8.34%, 95% confidence interval, 7.06-9.63; number needed to harm = 12). There was no difference in other secondary outcomes. In a subgroup analysis (women >55 years vs ≤55, n = 736), older women were at increased risk of the primary outcome (relative risk, 1.40, 95% confidence interval, 1.12-1.76, P = .004), transfusion (relative risk, 4.20, 95% confidence interval, 1.65-10.72, P = .003), surgical site infection (relative risk, 1.35, 95% confidence interval, 1.01-1.81, P = .04), and return to the hospital (relative risk, 2.36, 95% confidence interval, 1.54-3.62, P < .0001). CONCLUSION: Preoperative anemia in women undergoing elective hysterectomy/myomectomy was common and is an independent risk factor for 30 day postoperative adverse outcomes, especially in older women.

Post-mastectomy radiation in node-positive breast cancer in Ontario.

More recent guidelines are more supportive for post-mastectomy radiation in all node-positive breast cancer patients. We examined the rate and predictors of post-mastectomy radiation receipt in Ontario Canada from 2010 to 2014. Of 6535 node-positive post-mastectomy patients, 73.9% received radiation. The rate was 68.7% (2903/4227) among women with 1-3 positive nodes. Radiation was less likely to be administered to women who were older, had high levels of comorbidity, or presented with early stages of breast cancer. Regional practice variation was reassuringly modest.

Association between known or strongly suspected malignant hyperthermia susceptibility and postoperative outcomes: an observational population-based study.

PURPOSE: Whether current standards of care management for malignant hyperthermia (MH)-susceptible patients result in acceptable postoperative clinical outcomes at a population level is not known. Our objective was to determine if patients with susceptibility to MH experienced similar outcomes as patients without MH susceptibility after surgery under general anesthesia. METHODS: This was a retrospective, population-based cohort study from 1 April 2009 until 31 March 2016 in the Canadian province of Ontario. Participants were adults who underwent common in- or outpatient surgeries under general anesthesia. The exposure studied was either known or strongly suspected MH susceptibility as determined by usage of a specific physician billing code. The primary outcome was a composite of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days. Separate analyses were employed, based on whether a patient had in- or outpatient surgery. Inverse probability of exposure weighting based on the propensity score was used to estimate adjusted exposure effects. RESULTS: The cohort included 957,876 patients (583,254 in- and 374,622 outpatients). There were 2,900 (0.3%) patients with a known or strong suspicion of MH susceptibility. For inpatients, the primary outcome occurred in 146,192 (25.1%) of the non-MH-susceptible group and in 337 (20.1%) of the MH-susceptible group (unadjusted risk difference [RD], -5.0%; 95% confidence interval [CI], -6.9 to -3.1%; P < 0.001). In outpatients, the primary outcome occurred in 9,146 (2.4%) of the non-MH-susceptible group and in 32 (2.6%) of the MH-susceptible group (RD, 0.2%; 95% CI, -0.7 to 1.1%; P = 0.72). After adjustment, MH susceptibility was not associated with the primary outcome in either the inpatients (adjusted risk difference [aRD], 1.2%; 95% CI, -1.3 to 3.6%; P = 0.35) or outpatients (aRD, -0.1%; 95% CI -1.0 to 0.9%; P = 0.90). CONCLUSIONS: Among adults in Ontario who underwent common surgeries under general anesthesia from 2009 to 2016, known or strongly suspected MH was not associated with a higher risk of adverse postoperative outcomes. These findings support the current standard of care management for MH-susceptible patients.

RéSUMé: OBJECTIF: Nous ignorons si les normes actuelles de gestion des soins de patients susceptibles d'hyperthermie maligne (HM) aboutissent à des résultats cliniques postopératoires acceptables à l'échelle d'une population. Notre objectif a été de déterminer si des patients présentant une susceptibilité à l'HM présentaient une évolution comparable à celle des patients non connus susceptibles après chirurgie sous anesthésie générale. MéTHODES: Il s'agissait d'une étude de cohorte rétrospective, basée sur une population de la province canadienne de l'Ontario allant du 1er avril 2009 au 31 mars 2016. Les participants étaient des adultes, hospitalisés ou ambulatoires, ayant subi des interventions sous anesthésie générale. L'exposition étudiée était une susceptibilité à l'HM connue ou fortement suspectée, déterminée par l'utilisation d'un code de facturation spécifique des médecins. Le critère d'évaluation principal était un critère composite incluant les décès toutes causes confondues, les réadmissions hospitalières ou les complications postopératoires majeures qui étaient survenus dans un délai de 30 jours postopératoires. Des analyses séparées ont été utilisées, selon que les patients avaient été hospitalisés ou opérés en chirurgie d'un jour. La probabilité inverse de la pondération de l'exposition basée sur le score pour la propension a servi à estimer les effets ajustés de l'exposition. RéSULTATS: La cohorte a inclus 957 876 patients (583 254 patients hospitalisés et 374 622 patients ambulatoires). Parmi eux, 2 900 patients (0,3 %) avaient une susceptibilité à l'HM connue ou fortement suspectée. Pour les patients hospitalisés, le critère d'évaluation principal est survenu chez 146 192 (25,1 %) des patients du groupe non susceptible d'HM et chez 337 (20,1 %) patients du groupe susceptible d'HM (différence de risques [DR] non ajustée : −5,0 %; intervalle de confiance [IC] à 95 % : −6,9 % à −3,1 %; P < 0,001). Pour les patients ambulatoires, le critère d'évaluation principal est survenu chez 9 146 (2,4 %) des patients du groupe non susceptible d'HM et chez 32 (2,6 %) patients du groupe susceptible d'HM (différence de risques [DR] non ajustée : 0,2 %; IC à 95 % : −0,7 % à 1,1 %; P = 0,72). Après ajustement, la susceptibilité à l'HM ne s'est pas avérée associée au critère d'évaluation principal dans le groupe de patients hospitalisés (différence de risques ajustée [DRa], 1,2 %; IC à 95 % : −1,3 % à 3,6 %; P = 0,35) ou dans le groupe de patients ambulatoires (DRa : −0,1 %; IC à 95 % : −1,0 % à 0,9 %; P = 0,90). CONCLUSIONS: Parmi les adultes de la province de l'Ontario ayant subi des interventions chirurgicales usuelles sous anesthésie générale entre 2009 et 2016, l'HM connue ou fortement suspectée n'a pas été associée à un plus grand risque d'évolution postopératoire défavorable. Ces constatations sont en faveur du maintien des normes des soins actuels pour la gestion des patients susceptibles d'HM.

Secular trends in the incidence and timing of surgical intervention for congenital undescended testis and surgically treated hypospadias in Ontario, Canada between 1997 and 2007.

INTRODUCTION: Recent studies have suggested contradictory trends in the incidence of undescended testis (UDT) and hypospadias (HYP), partly because of methodological issues and ascertainment bias. The recently described association of "testicular dysgenesis syndrome" links concomitant UDT and HYP, with decreasing sperm counts and testicular cancer. Current guidelines suggest that orchidopexy for UDT should be performed by 18 months of age. OBJECTIVE: We conducted a retrospective population-based cohort study to estimate the incidence of UDT, HYP, and concomitant UDT and HYP in Ontario, based on a surgical procedure performed in the 5 years after birth. We hypothesized that the incidence of UDT and HYP are stable in the province of Ontario, Canada, over an 11-year time period. STUDY DESIGN: Linked administrative databases held at the Institute of Clinical Evaluative Sciences (ICES) in the province of Ontario, were used to identify all live male newborns between 1997 and 2007. Incidence rates of UDT, HYP and concomitant UDT and HYP were calculated by identifying a surgical procedure for these anomalies, within 5 years of birth. Incidence trends were analyzed using the Cochrane Armitage test for trend. Age at surgery for surgical intervention for an orchidopexy or HYP repair was determined. RESULTS: The incidence of UDT, defined by an orchidopexy within 5 years of birth, has remained stable in Ontario, Canada (8.2/1000 male live births, p-value for trend 0.9, 95% CI 8.0-8.4). The incidence of hypospadias has similarly remained stable (3.8/1000 male live births, p-value for trend 0.8, 95% CI 3.7-3.9). The incidence of concomitant UDT and HYP repair showed a significant increase over the 11-year period (0.2/1000 male live births, p-value for trend 0.03, 95% CI 0.2-0.3). The median age at orchidopexy (23 months, IQR 16-34 months) was beyond guideline recommendations, with earlier orchidopexy in recent years. The median age at hypospadias repair was 17 months (IQR 12-26 months). DISCUSSION: The variable rates of incidence for UDT and HYP can be explained by variations in study methodology and differing data sources utilized. The current study uses a surgical procedure to minimize information bias to correctly identify index cases of UDT and HYP. CONCLUSIONS: The incidence of undescended testis and hypospadias, over 5 years after birth, has remained stable in the province of Ontario between 1997 and 2007 (Summary Table). Concomitant UDT and HYP incidence showed a significant increase over this time period. Most boys in Ontario, Canada, undergo orchidopexy beyond 18 months of age.

Profile of CPAP treated patients in Ontario, Canada, 2006-2013: a population-based cohort study.

RATIONALE: Many studies have demonstrated the benefits of treating obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP). However, both recognition of OSA and acceptance of treatment are suboptimal. Current data on CPAP initiation at a population level is lacking. OBJECTIVES: The objectives were to determine the rate of CPAP initiations in Ontario, Canada (population ∼13,000,000), and to profile these individuals over time. METHODS: We conducted a population based cohort study between 2006 and 2013. All adults who initiated CPAP for OSA were included. Patient characteristics, comorbidities and health care utilization at the time of CPAP initiation were derived from provincial health administrative data. Changes in patient characteristics over time were assessed. RESULTS: Over eight years, 216,514 individuals initiated CPAP therapy in comparison to 802,188 individuals who underwent diagnostic polysomnography (PSG) during that time. The rate of new CPAP initiations increased from 18.6/10,000 in 2006 to 28.7/10,000 in 2008 and then plateaued with an annual increase of less than 1/10,000 from 2008 to 2013. More women and middle aged (50+) individuals initiated CPAP as did more low income Ontarians. Comorbidities were common and the frequency of congestive heart failure, chronic kidney disease, and cancer increased during the study period. CONCLUSIONS: Over an eight year period CPAP initiation appears to have plateaued in spite of increasing PSG testing; however, those receiving treatment with CPAP are increasingly complex and a greater proportion are women.

A population-based analysis of outcomes after radiotherapy in intensive care unit patients with lung cancer.

BACKGROUND: As the value of radiotherapy (RT) in intensive care unit (ICU) patients with lung cancer is of uncertain efficacy, we evaluated characteristics, outcomes and RT utilization for such patients in Ontario, Canada. METHODS: Multiple administrative databases were linked deterministically using unique encoded identifiers to identify eligible patients between April 1, 2007, and March 31, 2014. Differences in patient, treatment, institution and tumor characteristics between RT and non-RT groups at the level of episode of care were compared. Overall survival (OS) was evaluated using the Kaplan-Meier method, with differences compared using the log-rank test. Univariable and multivariable Cox proportional hazard modeling were performed to assess the effect of RT on survival. RESULTS: RT was delivered in 133 episodes of care to 1.0% (n=131) of the 13,739 unique patients with lung cancer. RT delivery was associated with younger age (median 65 vs. 68, P<0.001), ventilation (79.8% vs. 38.2%, P<0.001) and longer ventilation duration (median 6 vs. 0 days, P<0.001). Pre-ICU disposition via transfer (35.3% vs. 9.7%) or the emergency room (ER) (28.6% vs. 21.9%) was more likely in the RT group (P<0.001). RT delivery varied, with half of the regions treating ≤5 patients each. ICU discharge was common in both RT (n=75, 56.4%) and non-RT (n=10,405, 71.4%) cohorts. One-year OS was poor in both groups, but most notably in the RT group (11.3% vs. 42.4%). RT was associated with inferior 1-year OS on unadjusted modeling (HR =1.99, P<0.001), with ventilation and pre-ICU disposition adjusting this finding towards the null on multivariable modeling (HR =1.17, P=0.095). CONCLUSIONS: Major geographic disparities exist in the rare use of RT for lung cancer in the ICU. A significant proportion of patients receiving RT achieve discharge and a minority achieve prolonged survival, suggesting that RT use may not be futile.

Association Between Handover of Anesthesia Care and Adverse Postoperative Outcomes Among Patients Undergoing Major Surgery.

Importance: Handing over the care of a patient from one anesthesiologist to another occurs during some surgeries and might increase the risk of adverse outcomes. Objective: To assess whether complete handover of intraoperative anesthesia care is associated with higher likelihood of mortality or major complications compared with no handover of care. Design, Setting, and Participants: A retrospective population-based cohort study (April 1, 2009-March 31, 2015 set in the Canadian province of Ontario) of adult patients aged 18 years and older undergoing major surgeries expected to last at least 2 hours and requiring a hospital stay of at least 1 night. Exposure: Complete intraoperative handover of anesthesia care from one physician anesthesiologist to another compared with no handover of anesthesia care. Main Outcomes and Measures: The primary outcome was a composite of all-cause death, hospital readmission, or major postoperative complications, all within 30 postoperative days. Secondary outcomes were the individual components of the primary outcome. Inverse probability of exposure weighting based on the propensity score was used to estimate adjusted exposure effects. Results: Of the 313 066 patients in the cohort, 56% were women; the mean (SD) age was 60 (16) years; 49% of surgeries were performed in academic centers; 72% of surgeries were elective; and the median duration of surgery was 182 minutes (interquartile [IQR] range, 124-255). A total of 5941 (1.9%) patients underwent surgery with complete handover of anesthesia care. The percentage of patients undergoing surgery with a handover of anesthesiology care progressively increased each year of the study, reaching 2.9% in 2015. In the unweighted sample, the primary outcome occurred in 44% of the complete handover group compared with 29% of the no handover group. After adjustment, complete handovers were statistically significantly associated with an increased risk of the primary outcome (adjusted risk difference [aRD], 6.8% [95% CI, 4.5% to 9.1%]; P < .001), all-cause death (aRD, 1.2% [95% CI, 0.5% to 2%]; P = .002), and major complications (aRD, 5.8% [95% CI, 3.6% to 7.9%]; P < .001), but not with hospital readmission within 30 days of surgery (aRD, 1.2% [95% CI, -0.3% to 2.7%]; P = .11). Conclusions and Relevance: Among adults undergoing major surgery, complete handover of intraoperative anesthesia care compared with no handover was associated with a higher risk of adverse postoperative outcomes. These findings may support limiting complete anesthesia handovers.

Higher surgeon annual volume, but not years of experience, is associated with reduced rates of postoperative complications and reoperations after open abdominal aortic aneurysm repair.

OBJECTIVE: Volume-outcome relationships for open abdominal aortic aneurysm (AAA) repair have received less attention in publicly funded health systems. Furthermore, the roles of surgeon seniority (years of experience) and composite volume (encompassing all major arterial cases) on outcomes after open AAA repair are less well known. We sought to determine the effects of surgeon volume, surgeon years of experience, and composite volume on outcomes after elective open AAA repairs performed in Ontario, Canada. METHODS: Using a population-based, prospectively collected health administrative database, all elective open AAA repairs occurring in the province of Ontario from 2005 to 2014 were identified. Surgeon annual volume was classified by quintiles, with the highest volume quintile acting as the reference category. Multivariable logistic regression modeling was used, adjusting for patient factors (age, sex, comorbidities, year of procedure, income) to investigate the relationship between surgeon annual volume and 30-day mortality, 30-day major complications, 30-day reoperations, 1-year mortality, and 1-year reoperations (related to index procedure). The potential effects of annual surgeon composite volume and surgeon years of experience on postoperative outcomes were also explored. RESULTS: A total of 7211 elective open AAA repairs performed by 101 surgeons were identified between 2005 and 2014. Most of the operations were performed by vascular surgeons (81.5%), followed by cardiac (12.1%) and general surgeons (6.1%). Median number of procedures in the lowest quintile group was 3 repairs/y, whereas the highest quintile group performed 54 repairs/y. Overall 30-day mortality was 3%. No difference in mortality was detected in comparing the lowest with the highest volume groups (1.89% vs 3.01%; adjusted odds ratio [OR], 0.60; 95% confidence interval [CI], 0.27-1.33). The lowest volume group exhibited a higher 30-day complication rate (28.0% vs 20.4%; OR, 1.54; 95% CI, 1.15-2.06) and 30-day reoperation rate (10.53% vs 6.73%; OR, 1.64; 95% CI, 1.13-2.38) compared with the highest volume group. No effect of surgeon volume on 1-year mortality or 1-year reoperation was observed. Similarly, composite volume and surgeon years of experience were not associated with postoperative outcomes. CONCLUSIONS: In a single-payer system with a relatively high number of open AAA repairs/surgeon per year, surgeon annual volume had no effect on postoperative mortality but was associated with lower postoperative complication and reoperation rates.

Is there seasonality in hospitalizations for major depressive disorder in Canada?

Abstract Background Canada, a temperate country with four defined seasons incurs an annual productivity loss of over $30 billion on major depressive disorder (MDD); however it remains unknown whether inpatient hospitalization for MDD exhibits seasonal variations. Objective Our study objective was to determine if there are seasonal variations in hospitalization rates for MDD in Canada. Methods We used time series analysis to determine monthly rates of hospitalizations for MDD from 2006 - 2013, on data from population level health-administrative databases in Ontario, Canada. We also stratified analysis by gender and three age groups: 18 to 39, 40 to 65 and those over 65. We compared demographic and comorbidity profiles of patients admitted in April, August and December to elucidate if patient characteristics differed by season of admission. Results We identified a total of 130,336 admissions for MDD for 95,439 unique patients. Baseline characteristics of the patients were similar across seasons. We did not detect significant seasonality of hospitalizations for MDD across any of the gender or age subgroups. Discussion Our results question the popularly held belief that hospitalizations for MDD vary with seasons. These findings highlight the need for uniform hospital resource allocation for MDD throughout the year in Canada.