Accurate and timely testing for SARS-CoV-2 in the pediatric population is crucial to control the COVID-19 pandemic; saliva testing has been proposed as a less invasive alternative to nasopharyngeal swabs. We sought to compare the detection of SARS-CoV-2 using saliva versus nasopharyngeal swab in the pediatric population, and to determine the optimum time of testing for SARS-CoV-2 using saliva. We conducted a longitudinal diagnostic study in Ottawa, Canada, from Jan. 19 to Mar. 26, 2021. Children aged 3-17 years were eligible if they exhibited symptoms of COVID-19, had been identified as a high-risk or close contact to someone confirmed positive for SARS-CoV-2 or had travelled outside Canada in the previous 14 days. Participants provided both nasopharyngeal swab and saliva samples. Saliva was collected using a self-collection kit (DNA Genotek, OM-505) or a sponge-based kit (DNA Genotek, ORE-100) if they could not provide a saliva sample into a tube. Among 1580 paired nasopharyngeal and saliva tests, 60 paired samples were positive for SARS-CoV-2. Forty-four (73.3%) were concordant-positive results and 16 (26.6%) were discordant, among which 8 were positive only on nasopharyngeal swab and 8 were positive only on saliva testing. The sensitivity of saliva was 84.6% (95% confidence interval 71.9%-93.1%). Salivary testing for SARS-CoV-2 in the pediatric population is less invasive and shows similar detection of SARS-CoV-2 to nasopharyngeal swabs. It may therefore provide a feasible alternative for diagnosis of SARS-CoV-2 infection in children.

Background:Choosing Wisely is a high-profile campaign seeking to reduce the use of low-value care. We investigated the impact of a Choosing Wisely Canada recommendation against using a combination of angiotensin-converting-enzyme (ACE) inhibitors and angiotensin receptor blockers (ARBs) for the management of hypertension, heart failure or diabetic nephropathy on population-level use of these medications in British Columbia, Canada.Methods:We identified all people (any age) who were continuously registered with BC’s Medical Service Plan between 2010 and 2017 with the targeted conditions. Using prescription claims data and an interrupted time-series analysis, we estimated the number of people on combination therapy per month, the proportion of days covered (PDC) by combination therapy per month and proportion of all combination prescriptions started per month in the 2 years before and after the introduction of the recommendation on Oct. 29, 2014.Results:Of 1 104 593 people (mean age 65 yr, standard deviation 16 yr) in our study cohort, 4.6% were exposed to combination therapy, largely prescribed by family physicians (84%). The number of people on combination therapy and the PDC were declining before the recommendation, but the proportion of combination prescriptions started in the 2 years before the recommendation was increasing. After the recommendation, we observed no statistically significant changes in any outcome. The pre-existing downward trend of the monthly number of people decelerated (16.8, 95% confidence interval [CI] 14.0 to 19.5) and the proportion of prescriptions started increased (0.13%, 95% CI 0.08% to 0.18%).Interpretation:The Choosing Wisely Canada recommendation against using a combination of ACE inhibitors and ARBs was not associated with reduced combination therapy use in the targeted conditions. The observed pre-existing declines in this practice questions the process of selecting recommendations, and the optimal implementation and value of Choosing Wisely campaigns without other reinforcing interventions.

The advantage of coronary artery bypass grafting (CABG) over percutaneous coronary intervention (PCI), established in trials, may not be generalizable to populations in which the method of treatment determines the time to treatment. We sought to describe the methodology of a population-based observational study for assessing how changes in time to treatment may affect the comparative effectiveness of these 2 methods of coronary revascularization. We propose a framework of causal mediation analysis to compare the outcomes of choosing CABG over PCI, if patients selected for either method waited the same amount of time had they undergone a PCI. We will include patients who underwent a first-time, nonurgent isolated CABG or single-session PCI for multivessel or left main coronary artery disease from January 2001 to December 2016, in British Columbia. We will use absolute risk difference as a measure of the total effect of choosing CABG over PCI and partition it into the direct effect of the treatment choice and the effect mediated by the treatment-specific timing. Understanding how time to treatment mediates the relation between method of revascularization and outcomes will have implications for treatment selection, resource allocation and planning benchmarks. Findings on the benefits and risks of performing PCI or CABG within a certain time will guide multidisciplinary teams in determining the appropriate revascularization method for individual patients.

Background:In Quebec, antibiotic use is higher among outpatients with chronic diseases. We sought to measure compliance with provincial guidelines for the treatment of otitis media and common respiratory infections, and to measure variations in compliance according to the presence of certain chronic diseases.Methods:We conducted a population-based study of linked data on antibiotic dispensing covered by the public drug insurance plan between April 2010 and March 2017. We included patients who had consulted a primary care physician within 2 days before being dispensed an antibiotic for an infection targeted by provincial guidelines, including bronchitis in patients with chronic obstructive pulmonary disease, otitis media, pharyngitis, pneumonia and sinusitis. We computed proportions of prescriptions compliant with guidelines (use of recommended antibiotic for children, and use of recommended antibiotic and dosage for adults) by age group (children or adults) and chronic disease (respiratory, cardiovascular, diabetes, mental disorder or none). We measured the impact of chronic diseases on compliance using robust Poisson regression.Results:We analyzed between 14 677 and 198 902 prescriptions for each infection under study. Compliance was greater than 87% among children, but was lower among children with asthma (proportion ratios between 0.97 and 1.00). In adults, the chosen antibiotic was compliant for at least 73% of prescriptions, except for pharyngitis (≤ 61%). Accounting for dosage lowered compliance to between 31% and 61%. Compliance was lower in the presence of chronic diseases (proportion ratios between 0.94 and 0.98).Interpretation:It is possible that prescribing noncompliant prescriptions was sometimes appropriate, but the high frequency of noncompliance suggests room for improvement. Given that variations associated with chronic diseases were small, disease-specific guidelines for antibiotic prescriptions are likely to have a limited impact on compliance.

Background:It is unknown how much of current physician home visit volume is driven by low-complexity or low-continuity visits. Our objectives were to measure physician home visit volumes and costs in Ontario from 2005/06 to 2018/19, and to compare patient characteristics and postvisit use of health care services across home visit types.Methods:This was a retrospective cross-sectional study using health administrative data. We examined annual physician home visit volumes and costs from 2005/06 to 2018/19 in Ontario, and characteristics and postvisit use of health care services of residents who received at least 1 home visit from any physician in 2014/15 to 2018/19. We categorized home visits as palliative, provided to a patient who also received home care services or “other,” and compared characteristics and outcomes between groups.Results:A total of 4 418 334 physician home visits were performed between 2005/06 and 2018/19. More than half (2 256 667 [51.1%]) were classified as “other” and accounted for 39.1% ($22 million) of total annual physician billing costs. From 2014/15 to 2018/19, of the 413 057 home visit patients, 240 933 (58.3%) were adults aged 65 or more, and 323 283 (78.3%) lived in large urban areas. Compared to the palliative care and home care groups, the “other” group was younger, had fewer comorbidities, and had lower rates of emergency department visits and hospital admissions in the 30 days after the visit.Interpretation:About half of physician home visits in 2014/15 to 2018/19 were to patients who were receiving neither palliative care nor home care, a group that was younger and healthier, and had low use of health care services after the visit. There is an opportunity to refine policy tools to target patients most likely to benefit from physician home visits.

Background:Early identification of people with diabetes or prediabetes enables greater opportunities for glycemic control and management strategies to prevent related complications. To identify gaps in screening for these conditions, we examined population trends in receipt of timely glucose testing overall and in specific clinical subgroups.Methods:Using linked administrative databases, we conducted a retrospective cohort study of people aged 40 years and older without diabetes at baseline. Our primary outcome was up-to-date glucose testing, defined as having received testing at least once in the 3 years before each index year from 2010 to 2017, using linked administrative databases of people residing in Ontario, Canada. We calculated rates of up-to-date testing by age group, sex, ethnicity (South Asian, Chinese, general population) and comorbidities (hypertension, hyperlipidemia, cardiovascular disease).Results:Over the 8-year study period, up-to-date glucose testing rates were stable at 67% for men and 77% for women (both relative risk 1.00 per year; 95% confidence interval 1.00–1.00). Testing rates were significantly lower in men than in women (all age groups p < 0.001) and lower in younger than older age groups (except those aged ≥ 80 yr). South Asian people had the highest testing rates, although among people aged 70 years or older, testing was highest in the general population (p < 0.001). Among people with hypertension, hyperlipidemia and cardiovascular disease, annual testing rates were also stable, but only 58% overall among people with hypertension.Interpretation:We found lower glucose testing rates in younger men and people with hypertension. Our findings reinforce the need for initiatives to increase awareness of glycemic testing.

Background:The exposure risks to front-line health care workers caring for patients with SARS-CoV-2 infection undergoing surgery or obstetric delivery are unclear, and an understanding of sample types that may harbour virus is important for evaluating risk. We sought to determine whether SARS-CoV-2 viral RNA from patients with SARS-CoV-2 infection undergoing surgery or obstetric delivery was present in the peritoneal cavity of male and female patients, in the female reproductive tract, in the environment of the surgery or delivery suite (surgical instruments or equipment used, air or floors), and inside the masks of the attending health care workers.Methods:We conducted a cross-sectional study from November 2020 to May 2021 at 2 tertiary academic Toronto hospitals, during urgent surgeries or obstetric deliveries for patients with SARS-CoV-2 infection. The presence of SARS-CoV-2 viral RNA in patient, environmental and air samples was identified by real-time reverse transcription polymerase chain reaction (RT-PCR). Air samples were collected using both active and passive sampling techniques. The primary outcome was the proportion of health care workers’ masks positive for SARS-CoV-2 RNA. We included adult patients with positive RT-PCR nasal swab undergoing obstetric delivery or urgent surgery (from across all surgical specialties).Results:A total of 32 patients (age 20–88 yr) were included. Nine patients had obstetric deliveries (6 cesarean deliveries), and 23 patients (14 male) required urgent surgery from the orthopedic or trauma, general surgery, burn, plastic surgery, cardiac surgery, neurosurgery, vascular surgery, gastroenterology and gynecologic oncology divisions. SARS-CoV-2 RNA was detected in 20 of 332 (6%) patient and environmental samples collected: 4 of 24 (17%) patient samples, 5 of 60 (8%) floor samples, 1 of 54 (2%) air samples, 10 of 23 (43%) surgical instrument or equipment samples, 0 of 24 cautery filter samples and 0 of 143 (95% confidence interval 0–0.026) inner surface of mask samples.Interpretation:During the study period of November 2020 to May 2021, we found evidence of SARS-CoV-2 RNA in a small but important number of samples obtained in the surgical and obstetric operative environment. The finding of no detectable virus inside the masks worn by the health care teams would suggest a low risk of infection for health care workers using appropriate personal protective equipment.

BackgroundFirearm misuse is common in cases of homicide, suicide and unintentional injury; this is a major public health issue, with societal and economic costs extending beyond the immediate injury or loss of life. We sought to review the evidence on the effectiveness of Canadian legislation in reducing deaths caused by firearms.MethodsFive databases (PubMed, Embase, CINAHL, Web of Science and Scopus) were searched from inception to May 2021 for studies evaluating the effect of Canadian gun control laws Bill C-51 (1977), Bill C-17 (1991) and Bill C-68 (1995) on rates of firearm-related death. Two reviewers performed article screening independently and in duplicate. We synthesized data using descriptive statistics. The primary outcome of interest was firearm-related mortality rates. Because of study heterogeneity, a meta-analysis was not performed.ResultsOverall, 1479 articles were screened, and 18 studies were included. Ten studies examined the effect on homicides, of which 5 reported a reduction during the postlegislation period; 1 study reported evidence of substitution from firearms to other methods of homicide among people aged 15–24 years. Eleven studies evaluated the effect on suicides, with 9 finding a reduction in suicide rates. Eight of these studies reported evidence of substitution from firearms to other suicide methods. Two studies investigated accidental deaths; neither reported any benefit after legislation.InterpretationEvidence supporting the effectiveness of Canadian firearms legislation in the reduction of homicide and accidental death rates is inconclusive; a decrease in firearm-related suicide rates was observed by most studies, but evidence of method substitution was also identified. Re-evaluation of existing laws may be beneficial to build an improved and effective evidence-based national framework for prevention of gun violence. PROSPERO registrationCRD42020192486

BackgroundOutbreaks of SARS-CoV-2 in shelters and congregate living settings are a major concern because of overcrowding and because resident populations are often at high risk for infection. The objective of this study was to describe the development, implementation and assessment of the COVID-19 Community Response Team, a program that enabled Women’s College Hospital in Toronto, Ontario, to work in partnership with shelters and congregate living settings to prevent outbreaks.MethodsThe Community Response Team, associated with Women’s College Hospital, an academic ambulatory hospital, carried out mobile testing for SARS-CoV-2, supported outbreak management and prevention through ongoing onsite partnership with medical staff, and conducted infection prevention and control (IPC) training to shelter staff. We conducted a descriptive analysis of the sites supported by the program between Apr. 20, 2020, and Aug. 15, 2020. We also assessed the program’s feasibility (number of completed needs assessments, mobile testing events and IPC training events, and median time from referral to service delivery), adoption (number of nasopharyngeal swabs, number of pre- and post-program outbreaks and IPC uptake) and acceptability or satisfaction.ResultsThe Community Response Team supported 32 sites. Of those, 30 completed an intake needs assessment, 24 completed mobile testing for SARS-CoV-2 and 15 received IPC support. Mobile testing resulted in the collection of 1566 nasopharyngeal swabs, of which 64 were positive for SARS-CoV-2 infection. Three sites had confirmed outbreaks. The median time from referral to needs assessment was 4 days (interquartile range [IQR] 1–13 days), and the median time to the testing day was 9 days (IQR 1–49 days). The median time from referral to IPC staff training was 14 days (IQR 4–79 days), and 100% of respondents reported being pleased or very pleased with the training. During the follow-up period, the 3 facilities with outbreaks overcame those outbreaks. Three sites supported by the Community Response Team had further single cases, but no site reported subsequent or secondary outbreaks.InterpretationThe Community Response Team program led to the transfer of IPC knowledge, allowed for the management and prevention of SARS-CoV-2 outbreaks, and demonstrated feasibility. Collaborative supports between hospitals and the community housing sector may serve as models for ongoing system integration beyond the COVID-19 pandemic.

Background:The population that visits emergency departments frequently is heterogeneous and at high risk for mortality. This study aimed to characterize these patients in Ontario and Alberta, compare them with controls who do not visit emergency departments frequently, and identify subgroups.Methods:This was a retrospective cohort study that captured patients in Ontario or Alberta from fiscal years 2011/12 to 2015/16 in the Dynamic Cohort from the Canadian Institute for Health Information, which defined people with frequent visits to the emergency department in the top 10% of annual visits and randomly selected controls from the bottom 90%. We included patients 18 years of age or older and linked to emergency department, hospitalization, continuing care, home care and mental health–related hospitalization data. We characterized people who made frequent visits to the emergency department over time, compared them with controls and identified subgroups using cluster analysis. We examined emergency department visit acuity using the Canadian Triage and Acuity Scale.Results:The number of patients who made frequent visits to the emergency department ranged from 435 334 to 477 647 each year in Ontario (≥ 4 visits per year), and from 98 840 to 105 047 in Alberta (≥ 5 visits per year). The acuity of these visits increased over time. Those who made frequent visits to the emergency department were older and used more health care services than controls. We identified 4 subgroups of those who made frequent visits: “short duration” (frequent, regularly spaced visits), “older patients” (median ages 69 and 64 years in Ontario and Alberta, respectively; more comorbidities; and more admissions), “young mental health” (median ages 45 and 40 years in Ontario and Alberta, respectively; and common mental health–related and alcohol-related visits) and “injury” (increased prevalence of injury-related visits).Interpretation:From 2011/12 to 2015/16, people who visited emergency departments frequently had increasing visit acuity, had higher health care use than controls, and comprised distinct subgroups. Emergency departments should codevelop interventions with the identified subgroups to address patient needs.