Wait times and breast cancer survival: a population-based retrospective cohort study using CanIMPACT data.

PURPOSE: The time from breast cancer surgery to chemotherapy has been shown to affect survival outcomes; however, the effect of time from first breast cancer-related healthcare contact to first cancer specialist consultation, or the time from first breast cancer-related healthcare contact to adjuvant chemotherapy on survival has not been well explored. We aimed to determine whether various wait times along the breast cancer treatment pathway (contact-to-consultation, contact-to-chemotherapy, surgery-to-chemotherapy) were associated with overall survival in women within the Canadian province of Ontario. METHODS: We performed a population-based retrospective cohort study of women diagnosed with stage I-III breast cancer in Ontario between 2007 and 2011 who received surgery and adjuvant chemotherapy. This was the Ontario cohort of a larger, nationwide study (the Canadian Team to improve Community-Based Cancer Care along the Continuum - CanIMPACT). We used Cox-proportional hazards regression to determine the association between the contact-to-consultation, contact-to-chemotherapy, and surgery-to-chemotherapy intervals and overall survival while adjusting for cancer stage, age, comorbidity, neighborhood income, immigration status, surgery type, and method of cancer detection. RESULTS: Among 12,782 breast cancer patients, longer surgery-to-chemotherapy intervals (HR 1.13, 95% CI 1.03-1.18 per 30-day increase), but not the contact-to-consultation (HR 0.979, 95% CI 0.95-1.01 per 30-day increase), nor the more comprehensive contact-to-chemotherapy intervals (HR 1.00, 95% CI 0.98-1.02 per 30-day increase) were associated with decreased survival in our adjusted analyses. CONCLUSION: Our findings emphasize the prognostic importance of a shorter surgery-to-chemotherapy interval, whereas the contact-to-consultation and contact-to-chemotherapy intervals have less impact on survival outcomes.

Characteristics of primary care practices by proportion of patients unvaccinated against SARS-CoV-2: a cross-sectional cohort study.

BACKGROUND: Variations in primary care practices may explain some differences in health outcomes during the COVID-19 pandemic. We sought to evaluate the characteristics of primary care practices by the proportion of patients unvaccinated against SARS-CoV-2. METHODS: We conducted a population-based, cross-sectional cohort study using linked administrative data sets in Ontario, Canada. We calculated the percentage of patients unvaccinated against SARS-CoV-2 enrolled with each comprehensive-care family physician, ranked physicians according to the proportion of patients unvaccinated, and identified physicians in the top 10% (v. the other 90%). We compared characteristics of family physicians and their patients in these 2 groups using standardized differences. RESULTS: We analyzed 9060 family physicians with 10 837 909 enrolled patients. Family physicians with the largest proportion (top 10%) of unvaccinated patients (n = 906) were more likely to be male, to have trained outside of Canada, to be older, and to work in an enhanced fee-for-service model than those in the remaining 90%. Vaccine coverage (≥ 2 doses of SARS-CoV-2 vaccine) was 74% among patients of physicians with the largest proportion of unvaccinated patients, compared with 87% in the remaining patient population. Patients in the top 10% group tended to be younger and live in areas with higher levels of ethnic diversity and immigration and lower incomes. INTERPRETATION: Primary care practices with the largest proportion of patients unvaccinated against SARS-CoV-2 served marginalized communities and were less likely to use team-based care models. These findings can guide resource planning and help tailor interventions to integrate public health priorities within primary care practices.

Federal opioid agonist therapy policy: interrupted time series analysis of the impact of the methadone exemption removal across eight provinces in Canada.

BACKGROUND: Federal deregulation of opioid agonist therapies are an attractive policy option to improve access to opioid use disorder care and achieve widespread beneficial impacts on growing opioid-related harms. There have been few evaluations of such policy interventions and understanding effects can help policy planning across jurisdictions. METHODS: Using health administrative data from eight of ten Canadian provinces, this study evaluated the impacts of Health Canada's decision in May 2018 to rescind the requirement for Canadian health professionals to obtain an exemption from the Canadian Drugs and Substance Act to prescribe methadone for opioid use disorder. Over the study period of June 2017 to May 2019, we used descriptive statistics to capture overall trends in the number of agonist therapy prescribers across provinces and we used interrupted time series analysis to determine the effect of this decision on the trajectories of the agonist therapy prescribing workforces. RESULTS: There were important baseline differences in the numbers of agonist therapy prescribers. The province with the highest concentration of prescribers had 7.5 more prescribers per 100,000 residents compared to the province with the lowest. All provinces showed encouraging growth in the number of prescribers through the study period, though the fastest growing province grew 4.5 times more than the slowest. Interrupted time series analyses demonstrated a range of effects of the federal policy intervention on the provinces, from clearly positive changes to possibly negative effects. CONCLUSIONS: Federal drug regulation policy change interacted in complex ways with provincial health professional regulation and healthcare delivery, kaleidoscoping the effects of federal policy intervention. For Canada and other health systems such as the US, federal policy must account for significant subnational variation in OUD epidemiology and drug regulation to maximize intended beneficial effects and mitigate the risks of negative effects.

Examining the impact of the COVID-19 pandemic on homecare services among individuals with traumatic and non-traumatic spinal cord injuries.

STUDY DESIGN: Descriptive repeated-cross sectional retrospective longitudinal cohort study. OBJECTIVE: To investigate the impact of the COVID-19 pandemic on homecare services in individuals with traumatic or non-traumatic Spinal Cord Injury (SCI). SETTING: Health administrative database in Ontario, Canada. METHODS: A repeated cross-sectional study using linked health administrative databases from March 2015 to June 2022. Monthly homecare utilization was assessed in 3381 adults with SCI using Autoregressive Integrated Moving Average (ARIMA) models. RESULTS: Compared to pre-pandemic levels, between March 2020 to June 2022, the traumatic group experienced a decrease in personal and/or homemaking services, as well as an increase in nursing visits from April 2020-March 2022 and June 2022. Case management increased at various times for the traumatic group, however therapies decreased in May 2020 only. The non-traumatic group experienced a decrease in personal and/or homemaking services in July 2020, as well as an increase in nursing visits from March 2020 to February 2021 and sporadically throughout 2020. Case management also increased at certain points for the non-traumatic group, but therapies decreased in April 2020, July 2020, and September 2021. CONCLUSION: The traumatic group had decreases in personal and/or homemaking services. Both groups had increases in nursing services, increases in case management, and minimal decreases in therapies at varying times during the pandemic. Investigation is warranted to understand the root cause of these changes, and if they resulted in adverse outcomes.

Operational status of mental health, substance use, and problem gambling services: A system-level snapshot two years into the COVID-19 pandemic.

BACKGROUND: The aim of this paper is to provide a system-level snapshot of the operational status of mental health, substance use, and problem gambling services 2 years into the pandemic in Ontario, Canada, with a specific focus on services that target individuals experiencing vulnerable circumstances (e.g., homelessness and legal issues). METHODS: We examined data from 6038 publicly funded community services that provide mental health, substance use, and problem gambling services in Ontario. We used descriptive statistics to describe counts and percentages by service type and specialisation of service delivery. We generated cross-tabulations to analyse the relationship between the service status and service type for each target population group. RESULTS: As of March 2022, 38.4% (n = 2321) of services were fully operational, including 36.0% (n = 1492) of mental health, 44.1% (n = 1037) of substance use, and 23.4% (n = 78) of problem gambling services. These service disruptions were also apparent among services tailored to sexual/gender identity (women/girls, men/boys, 2SLGBTQQIA + individuals), individuals with legal issues, with acquired brain injury, and those experiencing homelessness. CONCLUSION: Accessible community-based mental health, substance use and problem gambling services are critical supports, particularly for communities that have historically contended with higher needs and greater barriers to care relative to the general population. We discuss the public health implications of the findings for the ongoing pandemic response and future emergency preparedness planning for community-based mental health, substance use and problem gambling services.

MR Imaging of Pediatric Neuroblastoma: Is Gadolinium Enhancement Necessary for Evaluation of Image-Defined-Risk Factors?

Background: Pre-treatment stratification and outcomes of neuroblastoma patients often depend on the assessment of image-defined risk factors (IDRFs) on MR Imaging, usually using Gadolinium-contrast materials which are cautioned in pediatrics. We aimed to address whether gadolinium contrast-enhanced sequences are necessary to identify the presence/absence of IDRFs. Methods: Patients with neuroblastoma with MR imaging were retrospectively identified from 2005 to 2021. Ninety confirmed IDRFs were evaluated in 23 patients. Corresponding MR studies were anonymized, randomized, and independently evaluated by 3 fellowship-trained pediatric radiologists. Each radiologist assessed the studies twice. At the first reading, all enhanced sequences were omitted, while in the second reading, the full study with enhanced sequences were included. Consensus reading was obtained among readers. Inter- and intra-rater agreements using Kappa statistics (κ) as well as the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of non-enhanced MR in assessing IDRFs with respect to enhanced MR were calculated. Results: There were substantial (ĸ: 0.64-0.73) intra-reader agreements, and moderate to substantial (ĸ: 0.57-0.62) inter-reader agreements among radiologists in identifying IDRFs using non-enhanced MR. Non-enhanced MR had a sensitivity of 87.8% (95% CI [79-94]), specificity of 93% (89-96), PPV of 82.3 (73-89), NPV of 95.4 (92-98), and accuracy of 91.6 (88-94) in identifying IDRFs. However, 5/23 patients (21.7%) had a change in staging with the inclusion of contrast sequences. Conclusion: Although contrast sequences have a role in IDRF assessment, the majority can be adequately assessed on MR without gadolinium-contrast enhancement. Validation in a larger cohort is an important next step.

Emulating a Target Trial Using Primary-Care Electronic Health Records: Sodium-Glucose Cotransporter 2 Inhibitor Medications and Hemoglobin A1c.

Substantial effort has been dedicated to conducting randomized controlled experiments to generate clinical evidence for diabetes treatment. Randomized controlled experiments are the gold standard for establishing cause and effect. However, due to their high cost and time commitment, large observational databases such as those comprised of electronic health record (EHR) data collected in routine primary care may provide an alternative source with which to address such causal objectives. We used a Canadian primary-care data repository housed at the University of Toronto (Toronto, Ontario, Canada) to emulate a randomized experiment. We estimated the effectiveness of sodium-glucose cotransporter 2 inhibitor (SGLT-2i) medications for patients with diabetes using hemoglobin A1c (HbA1c) as a primary outcome and marker for glycemic control from 2018 to 2021. We assumed an intention-to-treat analysis for prescribed treatment, with analyses based on the treatment assigned rather than the treatment eventually received. We defined the causal contrast of interest as the net change in HbA1c (percent) between the group receiving the standard of care versus the group receiving SGLT-2i medication. Using a counterfactual framework, marginal structural models demonstrated a reduction in mean HbA1c level with the initiation of SGLT-2i medications. These findings provided effect sizes similar to those from earlier clinical trials on assessing the effectiveness of SGLT-2i medications.

Seizure outcome of pediatric magnetic resonance-guided laser interstitial thermal therapy versus open surgery: A matched noninferiority cohort study.

OBJECTIVE: Minimally invasive magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) has been proposed as an alternative to open epilepsy surgery, to address concerns regarding the risk of open surgery. Our primary hypothesis was that seizure freedom at 1 year after MRgLITT is noninferior to open surgery in children with drug-resistant epilepsy (DRE). The secondary hypothesis was that MRgLITT has fewer complications and shorter hospitalization than surgery. The primary objective was to compare seizure outcome of MRgLITT to open surgery in children with DRE. The secondary objective was to compare complications and length of hospitalization of the two treatments. METHODS: This retrospective multicenter cohort study included children with DRE treated with MRgLITT or open surgery with 1-year follow-up. Exclusion criteria were corpus callosotomy, neurostimulation, multilobar or hemispheric surgery, and lesion with maximal dimension > 60 mm. MRgLITT patients were propensity matched to open surgery patients. The primary outcome was seizure freedom at 1 year posttreatment. The difference in seizure freedom was compared using noninferiority test, with noninferiority margin of -10%. The secondary outcomes were complications and length of hospitalization. RESULTS: One hundred eighty-five MRgLITT patients were matched to 185 open surgery patients. Seizure freedom at 1 year follow-up was observed in 89 of 185 (48.1%) MRgLITT and 114 of 185 (61.6%) open surgery patients (difference = -13.5%, one-sided 97.5% confidence interval = -23.8% to ∞, pNoninferiority  = .79). The lower confidence interval boundary of -23.8% was below the prespecified noninferiority margin of -10%. Overall complications were lower in MRgLITT compared to open surgery (10.8% vs. 29.2%, respectively, p < .001). Hospitalization was shorter for MRgLITT than open surgery (3.1 ± 2.9 vs. 7.2 ± 6.1 days, p < .001). SIGNIFICANCE: Seizure outcome of MRgLITT at 1 year posttreatment was inferior to open surgery. However, MRgLITT has the advantage of better safety profile and shorter hospitalization. The findings will help counsel children and parents on the benefits and risks of MRgLITT and contribute to informed decision-making on treatment options.

Estimation of marginal structural models under irregular visits and unmeasured confounder: calibrated inverse probability weights.

Clinical information collected in electronic health records (EHRs) is becoming an essential source to emulate randomized experiments. Since patients do not interact with the healthcare system at random, the longitudinal information in large observational databases must account for irregular visits. Moreover, we need to also account for subject-specific unmeasured confounders which may act as a common cause for treatment assignment mechanism (e.g. glucose-lowering medications) while also influencing the outcome (e.g. Hemoglobin A1c). We used the calibration of longitudinal weights to improve the finite sample properties and to account for subject-specific unmeasured confounders. A Monte Carlo simulation study is conducted to evaluate the performance of calibrated inverse probability estimators using time-dependent treatment assignment and irregular visits with subject-specific unmeasured confounders. The simulation study showed that the longitudinal weights with calibrated restrictions improved the finite sample bias when compared to the stabilized weights. The application of the calibrated weights is demonstrated using the exposure of glucose lowering medications and the longitudinal outcome of Hemoglobin A1c. Our results support the effectiveness of glucose lowering medications in reducing Hemoglobin A1c among type II diabetes patients with elevated glycemic index ([Formula: see text]) using stabilized and calibrated weights.

Opportunities to improve quality of care for cancer survivors in primary care: findings from the BETTER WISE study.

PURPOSE: The BETTER WISE (Building on Existing Tools to Improve Chronic Disease Prevention and Screening in Primary Care for Wellness of Cancer Survivors and Patients) intervention is an evidence-based approach to prevention and screening for cancers and chronic diseases in primary care that also includes comprehensive follow-up for breast, prostate and colorectal cancer survivors. We describe the process of harmonizing cancer survivorship guidelines to create a BETTER WISE cancer surveillance algorithm and describe both the quantitative and qualitative findings for BETTER WISE participants who were breast, prostate or colorectal cancer survivors. We describe the results in the context of the COVID-19 pandemic. METHODS: We reviewed high-quality survivorship guidelines to create a cancer surveillance algorithm. We conducted a cluster randomized trial in three Canadian provinces with two composite index outcome measured 12 months after baseline, and also collected qualitative feedback on the intervention. RESULTS: There were 80 cancer survivors for whom we had baseline and follow-up data. Differences between the composite indices in the two study arms were not statistically significant, although a post hoc analysis suggested the COVID-19 pandemic was a key factor in these results. Qualitative finding suggested that participants and stakeholders generally viewed BETTER WISE positively and emphasized the effects of the pandemic. CONCLUSIONS AND IMPLICATIONS FOR CANCER SURVIVORS: BETTER WISE shows promise for providing an evidence-based, patient-centred, comprehensive approach to prevention, screening and cancer surveillance for cancer survivors in the primary care setting. TRIAL REGISTRATION: ISRCTN21333761. Registered on December 19, 2016, http://www.isrctn.com/ISRCTN21333761 .

Chronic pain trials often exclude people with comorbid depressive symptoms: A secondary analysis of 346 randomized controlled trials.

BACKGROUND: Chronic pain and depression are common comorbid conditions, but there is limited evidence-based guidance for management of the two conditions together. In recent years, there has been an increase in the number of chronic pain randomized controlled trials that collect depression outcomes, but it is unknown how often these trials include people with depression or significant depressive symptoms. If trials do not include participants representative of real-world populations, evidence and guidance generated from these trials risk being inapplicable for large proportions of the target population, or worse, risk harm. Thus, in order to identify pathways to improve the conduct of clinical trials, the aims of this study were to (1) estimate the proportion of randomized controlled trials evaluating chronic pain interventions and reporting depression outcomes that include participants with significant depressive symptoms; and (2) assess the variability of inclusion proportions by pain type, intervention type, gender, country of origin, and publication year. METHODS: Studies were extracted from an umbrella review of interventions for chronic pain that reported depression outcomes. Screening and data extraction were completed in duplicate and conflicts were resolved by a third author. Randomized controlled trials with at least 50% adult participants and validated depression scales were included, and randomized controlled trials with populations whose mean scores were at or above depression thresholds at baseline were considered to have included participants with depression. RESULTS: Of the 346 randomized controlled trials analyzed, 142 (41%) included participants with depression. Eight pain-type groups and nine intervention types were identified. Randomized controlled trials investigating fibromyalgia and mixed chronic pain had the highest proportion of participants with depression, whereas studies of arthritis and axial pain had among the lowest. Randomized controlled trials from the United States had a significantly lower inclusion proportion compared with non-US studies, especially for studies on arthritis. The increase in inclusion proportion by publication year was driven by the increase in fibromyalgia studies. DISCUSSION AND CONCLUSION: This study highlights opportunities to improve the conduct of chronic pain clinical trials. The majority of randomized controlled trials s analyzed evaluated participants without significant depressive symptoms at baseline, thus the findings synthesized in systematic reviews and subsequent guidelines are most applicable to the subset of real-world populations that do not have significant depressive symptoms. As well, systemic biases around psychological conditions and gender may be important contributors to differences in the study of depression in fibromyalgia compared with common conditions such as arthritis and axial pain. In order to better inform clinical practice, future research must intentionally include individuals with comorbid depression in trials of common chronic pain conditions, and consider methods to mitigate biases that may distort study design.

Examining the impact of COVID-19 on health care utilization among persons with chronic spinal cord injury/dysfunction: a population study.

STUDY DESIGN: A retrospective longitudinal cohort time-series analysis study. OBJECTIVES: To examine healthcare utilization and delivery during the COVID-19 pandemic in individuals with spinal cord injury/dysfunction (SCI/D). SETTING: Health administrative database in Ontario, Canada. METHODS: In 5754 individuals with SCI/D diagnosed from 2004-2014 and living in the community, healthcare utilization (physician visits, primary care visits, specialist visits, urologist visits, physiatrist visits, emergency department (ED) visits, and hospital admissions) and delivery (total, in-person, virtual) were determined at the (1) pre-pandemic period (March 2015 to February 2020), (2) initial pandemic onset period (March 2020-May 2020), and (3) pandemic period (June 2020 to March 2022). Autoregressive integrated moving average (ARIMA) modelling was conducted to determine the impact of the pandemic on monthly healthcare utilization and delivery. RESULTS: The initial pandemic onset period had a significant reduction of 24% in physicians (p = 0.0081), 35% in specialists (p < 0.0001), and 30% in urologist (p < 0.0001) visits, compared to pre-pandemic levels, with a partial recovery as the pandemic progressed. In April 2020, compared to the pre-pandemic period, a significant increase (p < 0.0001) in virtual visits for physicians, specialists, urologists, and primary care was found. The initial pandemic onset period had a 58% decrease in hospital admissions (p = 0.0011), compared to the pre-pandemic period. CONCLUSION: Healthcare utilization dropped in the initial pandemic onset period as physicians, specialists, and urologists, as well as hospitalization visits decreased significantly (p < 0.05) versus pre-pandemic levels. Virtual visit increases compensated for in-person visit decreases as the pandemic progressed to allow for total visits to partially recover.

Quality indices for topic model selection and evaluation: a literature review and case study.

BACKGROUND: Topic models are a class of unsupervised machine learning models, which facilitate summarization, browsing and retrieval from large unstructured document collections. This study reviews several methods for assessing the quality of unsupervised topic models estimated using non-negative matrix factorization. Techniques for topic model validation have been developed across disparate fields. We synthesize this literature, discuss the advantages and disadvantages of different techniques for topic model validation, and illustrate their usefulness for guiding model selection on a large clinical text corpus. DESIGN, SETTING AND DATA: Using a retrospective cohort design, we curated a text corpus containing 382,666 clinical notes collected between 01/01/2017 through 12/31/2020 from primary care electronic medical records in Toronto Canada. METHODS: Several topic model quality metrics have been proposed to assess different aspects of model fit. We explored the following metrics: reconstruction error, topic coherence, rank biased overlap, Kendall's weighted tau, partition coefficient, partition entropy and the Xie-Beni statistic. Depending on context, cross-validation and/or bootstrap stability analysis were used to estimate these metrics on our corpus. RESULTS: Cross-validated reconstruction error favored large topic models (K ≥ 100 topics) on our corpus. Stability analysis using topic coherence and the Xie-Beni statistic also favored large models (K = 100 topics). Rank biased overlap and Kendall's weighted tau favored small models (K = 5 topics). Few model evaluation metrics suggested mid-sized topic models (25 ≤ K ≤ 75) as being optimal. However, human judgement suggested that mid-sized topic models produced expressive low-dimensional summarizations of the corpus. CONCLUSIONS: Topic model quality indices are transparent quantitative tools for guiding model selection and evaluation. Our empirical illustration demonstrated that different topic model quality indices favor models of different complexity; and may not select models aligning with human judgment. This suggests that different metrics capture different aspects of model goodness of fit. A combination of topic model quality indices, coupled with human validation, may be useful in appraising unsupervised topic models.

Ovarian cancer incidence and death in average-risk women undergoing bilateral salpingo-oophorectomy at benign hysterectomy.

BACKGROUND: Opportunistic bilateral salpingo-oophorectomy is often offered to patients undergoing benign hysterectomy to prevent ovarian cancer, but the magnitude of risk reduction obtained with bilateral salpingo-oophorectomy in this population remains unclear and must be weighed against potential risks of ovarian hormone deficiency. OBJECTIVE: This study aimed to quantify the relative and absolute risk reduction in ovarian cancer incidence and death associated with bilateral salpingo-oophorectomy at the time of benign hysterectomy. STUDY DESIGN: We performed a population-based cohort study of all adult women (≥20 years) undergoing benign hysterectomy from 1996 to 2010 in Ontario, Canada. Patients with ovarian pathology, previous breast or gynecologic cancer, or evidence of genetic susceptibility to malignancy were excluded. Inverse probability of treatment-weighted Fine-Gray subdistribution hazard models were used to quantify the effect of bilateral salpingo-oophorectomy on ovarian cancer incidence and death while accounting for competing risks and adjusting for demographic characteristics, gynecologic conditions, and comorbidities. Analyses were performed in all women and specifically in women of postmenopausal age (≥50 years) at the time of hysterectomy. RESULTS: We identified 195,282 patients (bilateral salpingo-oophorectomy, 24%; ovarian conservation, 76%) with a median age of 45 years (interquartile range, 40-51 years). Over a median follow-up of 16 years (interquartile range, 12-20 years), 548 patients developed ovarian cancer (0.3%), and 16,170 patients (8.3%) died from any cause. Bilateral salpingo-oophorectomy was associated with decreased ovarian cancer incidence (hazard ratio, 0.23; 95% confidence interval, 0.14-0.38; P<.001) and decreased ovarian cancer death (hazard ratio, 0.30; 95% confidence interval, 0.16-0.57; P<.001). At 20 years follow-up, the weighted cumulative incidences of ovarian cancer were 0.08% and 0.46% with bilateral salpingo-oophorectomy and ovarian conservation, respectively, yielding an absolute risk reduction of 0.38% (95% confidence interval, 0.32-0.45; number needed to treat, 260). After restricting to women aged ≥50 years at hysterectomy, the absolute risk reduction was 0.62% (95% confidence interval, 0.47-0.77; number needed to treat, 161). CONCLUSION: Bilateral salpingo-oophorectomy resulted in a significant absolute reduction in ovarian cancer among women undergoing benign hysterectomy. Population-average risk estimates derived in this study should be balanced against other potential implications of bilateral salpingo-oophorectomy to inform practice guidelines, patient decision-making, and surgical management.

Impact of Team-Based Care on Emergency Department Use.

PURPOSE: We sought to assess the impact of team-based care on emergency department (ED) use in the context of physicians transitioning from fee-for-service payment to capitation payment in Ontario, Canada. METHODS: We conducted an interrupted time series analysis to assess annual ED visit rates before and after transition from an enhanced fee-for-service model to either a team capitation model or a nonteam capitation model. We included Ontario residents aged 19 years and older who had at least 3 years of outcome data both pretransition and post-transition (N = 2,524,124). We adjusted for age, sex, income quintile, immigration status, comorbidity, and morbidity, and we stratified by rurality. A sensitivity analysis compared outcomes for team vs nonteam patients matched on year of transition, age, sex, rurality, and health region. RESULTS: We compared 387,607 team and 1,399,103 nonteam patients in big cities, 213,394 team and 380,009 nonteam patients in small towns, and 65,289 team and 78,722 nonteam patients in rural areas. In big cities, after adjustment, the ED visit rate increased by 2.4% (95% CI, 2.2% to 2.6%) per year for team patients and 5.2% (95% CI, 5.1% to 5.3%) per year for nonteam patients in the years after transition (P <.001). Similarly, there was a slower increase in ED visits for team relative to nonteam patients in small towns (0.9% [95% CI, 0.7% to 1.1%] vs 2.9% [95% CI, 2.8% to 3.1%], P <.001) and rural areas (‒0.5% [95% CI, -0.8% to 0.2%] vs 1.3% [95% CI, 1.0% to 1.6%], P <.001). Results were much the same in the matched analysis. CONCLUSIONS: Adoption of team-based primary care may reduce ED use. Further research is needed to understand optimal team composition and roles.

Family Physicians Stopping Practice During the COVID-19 Pandemic in Ontario, Canada.

We conducted 2 analyses using administrative data to understand whether more family physicians in Ontario, Canada stopped working during the COVID-19 pandemic compared with previous years. First, we found 3.1% of physicians working in 2019 (n = 385/12,247) reported no billings in the first 6 months of the pandemic; compared with other family physicians, a higher portion were aged 75 years or older (13.0% vs 3.4%, P <0.001), had fee-for-service reimbursement (37.7% vs 24.9%, P <0.001), and had a panel size under 500 patients (40.0% vs 25.8%, P <0.001). Second, a fitted regression line found the absolute increase in the percentage of family physicians stopping work was 0.03% per year from 2010 to 2019 (P = 0.042) but 1.2% between 2019 to 2020 (P <0.001). More research is needed to understand the impact of physicians stopping work on primary care attachment and access to care.

Non-negative matrix factorization temporal topic models and clinical text data identify COVID-19 pandemic effects on primary healthcare and community health in Toronto, Canada.

OBJECTIVE: To demonstrate how non-negative matrix factorization can be used to learn a temporal topic model over a large collection of primary care clinical notes, characterizing diverse COVID-19 pandemic effects on the physical/mental/social health of residents of Toronto, Canada. MATERIALS AND METHODS: The study employs a retrospective open cohort design, consisting of 382,666 primary care progress notes from 44,828 patients, 54 physicians, and 12 clinics collected 01/01/2017 through 31/12/2020. Non-negative matrix factorization uncovers a meaningful latent topical structure permeating the corpus of primary care notes. The learned latent topical basis is transformed into a multivariate time series data structure. Time series methods and plots showcase the evolution/dynamics of learned topics over the study period and allow the identification of COVID-19 pandemic effects. We perform several post-hoc checks of model robustness to increase trust that descriptive/unsupervised inferences are stable over hyper-parameter configurations and/or data perturbations. RESULTS: Temporal topic modelling uncovers a myriad of pandemic-related effects from the expressive clinical text data. In terms of direct effects on patient-health, topics encoding respiratory disease symptoms display altered dynamics during the pandemic year. Further, the pandemic was associated with a multitude of indirect patient-level effects on topical domains representing mental health, sleep, social and familial dynamics, measurement of vitals/labs, uptake of prevention/screening maneuvers, and referrals to medical specialists. Finally, topic models capture changes in primary care practice patterns resulting from the pandemic, including changes in EMR documentation strategies and the uptake of telemedicine. CONCLUSION: Temporal topic modelling applied to a large corpus of rich primary care clinical text data, can identify a meaningful topical/thematic summarization which can provide policymakers and public health stakeholders a passive, cost-effective, technology for understanding holistic impacts of the COVID-19 pandemic on the primary healthcare system and community/public-health.

The Impact of a Clinical Decision Support System for Addressing Physical Activity and Healthy Eating During Smoking Cessation Treatment: Hybrid Type I Randomized Controlled Trial.

BACKGROUND: People who smoke have other risk factors for chronic diseases, such as low levels of physical activity and poor diet. Clinical decision support systems (CDSSs) might help health care practitioners integrate interventions for diet and physical activity into their smoking cessation programming but could worsen quit rates. OBJECTIVE: The aims of this study are to assess the effects of the addition of a CDSS for physical activity and diet on smoking cessation outcomes and to assess the implementation of the study. METHODS: We conducted a pragmatic hybrid type I effectiveness-implementation trial with 232 team-based primary care practices in Ontario, Canada, from November 2019 to May 2021. We used a 2-arm randomized controlled trial comparing a CDSS addressing physical activity and diet to treatment as usual and used the Reach, Effectiveness, Adoption, Implementation, and Maintenance framework to measure implementation outcomes. The primary outcome was self-reported 7-day tobacco abstinence at 6 months. RESULTS: We enrolled 5331 participants in the study. Of these, 2732 (51.2%) were randomized to the intervention group and 2599 (48.8%) to the control group. At the 6-month follow-up, 29.7% (634/2137) of respondents in the intervention arm and 27.3% (552/2020) in the control arm reported abstinence from tobacco. After multiple imputation, the absolute group difference was 2.1% (95% CI -0.5 to 4.6; F1,1000.42=2.43; P=.12). Mean exercise minutes changed from 32 (SD 44.7) to 110 (SD 196.1) in the intervention arm and from 32 (SD 45.1) to 113 (SD 195.1) in the control arm (group effect: B=-3.7 minutes; 95% CI -17.8 to 10.4; P=.61). Servings of fruit and vegetables changed from 2.64 servings to 2.42 servings in the intervention group and from 2.52 servings to 2.45 servings in the control group (incidence rate ratio for intervention group=0.98; 95% CI 0.93-1.02; P=.35). CONCLUSIONS: A CDSS for physical activity and diet may be added to a smoking cessation program without affecting the outcomes. Further research is needed to improve the impact of integrated health promotion interventions in primary care smoking cessation programs. TRIAL REGISTRATION: ClinicalTrials.gov NCT04223336 https://www.clinicaltrials.gov/ct2/show/NCT04223336. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/19157.

Recent trends in adult body mass index and prevalence of excess weight: Data from the Canadian Primary Care Sentinel Surveillance Network.

OBJECTIVE: To explore recent body mass index (BMI) trends over time among Canadian adults seen in primary care to identify the best target groups for preventive interventions. DESIGN: Retrospective descriptive cohort design. SETTING: Data for this study were derived from the Canadian Primary Care Sentinel Surveillance Network database. PARTICIPANTS: All patients aged 18 years and older who had BMI measurements available between 2011 and 2016 were identified. A closed cohort (N = 243 078 unique patients) with a start date of January 1, 2011, was defined. Patients were excluded if key variables were missing or if BMI measurements were 15 kg/m2 or less or 50 kg/m2 or greater. MAIN OUTCOME MEASURES: The dependent variable for this study was BMI (kg/m2). Measured BMI values recorded in electronic medical records were used. A linear mixed-effect estimate was fit to model changes in BMI over time with control of baseline age and sex. RESULTS: Patients in the Canadian Primary Care Sentinel Surveillance Network database experienced a modest increase in mean (95% CI) BMI by 2.1% from 28.5 (28.4 to 28.6) kg/m2 in 2011 to 29.1 (28.9 to 29.2) kg/m2 in 2016 (P < .0001). This increase is not a measured difference in BMI in the same individual but reflects the difference in the average BMI of the population in 2011 versus 2016. Male patients had BMI values that were on average 1.02 kg/m2 higher than those of female patients (P < .0001). Mean BMI values increased most rapidly in young adults (18 to 34 years) compared with older adults. CONCLUSION: The findings indicate that current obesity management in primary care is failing to moderate weight trajectories in different groups by age and sex. The results also suggest that younger age groups, in whom accelerated weight gain occurred, should be the target of prevention initiatives.

Urinary podocyte-derived microparticles in youth with type 1 and type 2 diabetes.

AIMS/HYPOTHESIS: The release of podocyte-derived microparticles into the urine may reflect early kidney injury in diabetes. We measured the urinary excretion of podocyte-derived microparticles in youth with type 1 and type 2 diabetes, and related the values to blood pressure, renal function and blood glucose levels. METHODS: Cross-sectional, exploratory analysis of urine samples and clinical data from youth with type 1 (n = 53) and type 2 (n = 50) diabetes was carried out. Urinary podocyte-derived microparticle numbers, measured by flow cytometry, were assessed in relation to measures of blood glucose levels and renal function. RESULTS: Podocyte-derived microparticle excretion (MPE) normalised to urinary creatinine (MP/UCr) was higher in type 1 vs type 2 diabetes (median [IQR] MP/UCr: 7.88 [8.97] vs 1.84 [8.62]; p < 0.0001), despite the type 2 diabetes group having higher blood pressure (systolic blood pressure, median [range]: 124 [110-154] vs 114 [94-143] mmHg) and higher proportions of microalbuminuria (44.0% vs 13.2%), but shorter time since diabetes diagnosis (median [range]: 1.2 [0.0-7.0] vs 6.4 [2.0-13.9] years), than the type 1 diabetes cohort. MPE in youth with type 1 diabetes was associated with blood glucose (p = 0.01) and eGFR (p = 0.03) but not HbA1c, systolic or diastolic blood pressure or urine albumin/creatinine ratio. After adjustment for age at baseline, duration of diabetes, sex and BMI, the association with eGFR remained significant (p = 0.04). No associations were found between MPE and these clinical variables in youth with type 2 diabetes. CONCLUSIONS/INTERPRETATION: Significant associations between podocyte MPE, blood glucose levels and eGFR were observed in youth with type 1 diabetes but not in those with type 2 diabetes, notwithstanding increased renal pathology in the type 2 diabetes cohort. These findings suggest that podocyte injury differs in the two diabetes cohorts. Graphical abstract.