CMAJ open最新文献

Background: Accurate coding of diagnoses of SARS-CoV-2 infection in administrative data benefits population-based studies about the epidemiology, treatment and outcomes of COVID-19. We describe the validity of diagnoses of SARS-CoV-2 infection recorded in hospital discharge abstracts, emergency department records and outpatient physician service claims from 3 Canadian provinces.

Methods: In this cohort study, population-based inpatient, emergency department and outpatient records were linked to SARS-CoV-2 polymerase chain reaction (PCR; reference standard) test results from British Columbia, Manitoba and Ontario for Apr. 1, 2020, to Mar. 31, 2021. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of diagnoses of SARS-CoV-2 infection were estimated for each quarter in the study period, overall and by province, age group and sex.

Results: Our study encompassed more than 13 million SARS-CoV-2 PCR test results. Specificity and NPV of diagnoses of SARS-CoV-2 infection were consistently high (i.e., most estimates were > 95%). Overall sensitivity estimates were 86.2%, 60.4% and 20.3% in the first quarter for inpatient, emergency department and outpatient cohorts, and 66.2%, 47.5% and 25.0% in the last quarter, respectively. For inpatients, overall PPV estimates ranged from 50.0% to 66.4%. For emergency department patients, overall PPV estimates were 76.9% and 68.3% in the first and last quarters, respectively. For outpatients, PPV estimates were 6.8% and 29.1% in the first and last quarters, respectively.

Interpretation: We found variations in the validity of diagnoses for SARS-CoV-2 infection recorded in different health care settings, geographic areas and over time. Our multiprovince validation study provides evidence about the potential use of inpatient and emergency department records as an alternative to population-based laboratory data for identification of patients with SARS-CoV-2 infection, but does not support the use of outpatient claims for this purpose.

Background: Attachment to a regular primary care provider is associated with better health outcomes, but 15% of people in Canada lack a consistent source of ongoing primary care. We sought to evaluate trends in attachment to a primary care provider in Ontario in 2008-2018, through an equity lens and in relation to policy changes in implementation of payment reforms and team-based care.

Methods: Using linked, population-level administrative data, we conducted a retrospective observational study to calculate rates of patients attached to a regular primary care provider from Apr. 1, 2008, to Mar. 31, 2019. We evaluated the association of patient characteristics and attachment in 2018 using sex-stratified, adjusted, multivariable logistic regression models and used segmented piecewise regression to evaluate changing trends before and after implementation of a policy that restricted physician entry to alternate models.

Results: Attachment increased from 80.5% (n = 10 352 385) in 2008 to 88.9% of the population (n = 12 537 172) in 2018, but was lower among people with low comorbidity, high residential instability, material deprivation, rural residence and recent immigrants. Inequities narrowed for recent immigrants, males and people with lower incomes over the study period, but disparities persisted for these groups. Attachment grew by 1.47% annually until 2014 (p < 0.0001), but was stagnant thereafter (annual percent change of 0.13, p = 0.16).

Interpretation: Lack of sustained progress in attachment followed reduced levels of physician entry to alternate funding models. Although disparities narrowed for many groups over the study period, persistent gaps remained for immigrants and people with lower incomes; targeted interventions and policy changes are needed to address these persistent gaps.

Background: Little is known about patterns of coexisting conditions and their influence on clinical care or outcomes in adults admitted to hospital for community-acquired pneumonia (CAP). We sought to evaluate how coexisting conditions cluster in this population to advance understanding of how multimorbidity affects CAP.

Methods: We studied 11 085 adults admitted to hospital with CAP at 7 hospitals in Ontario, Canada. Using cluster analysis, we identified patient subgroups based on clustering of comorbidities in the Charlson Comorbidity Index. We derived and replicated cluster analyses in independent cohorts (derivation sample 2010-2015, replication sample 2015-2017), then combined these into a total cohort for final cluster analyses. We described differences in medications, imaging and outcomes.

Results: Patients clustered into 7 subgroups. The low comorbidity subgroup (n = 3052, 27.5%) had no comorbidities. The DM-HF-Pulm subgroup had prevalent diabetes, heart failure and chronic lung disease (n = 1710, 15.4%). One disease category defined each remaining subgroup, as follows: pulmonary (n = 1621, 14.6%), diabetes (n = 1281, 11.6%), heart failure (n = 1370, 12.4%), dementia (n = 1038, 9.4%) and cancer (n = 1013, 9.1%). Corticosteroid use ranged from 11.5% to 64.9% in the dementia and pulmonary subgroups, respectively. Piperacillin-tazobactam use ranged from 9.1% to 28.0% in the pulmonary and cancer subgroups, respectively. The use of thoracic computed tomography ranged from 5.7% to 36.3% in the dementia and cancer subgroups, respectively. Adjusting for patient factors, the risk of in-hospital death was greater in the cancer (adjusted odds ratio [OR] 3.12, 95% confidence interval [CI] 2.44-3.99), dementia (adjusted OR 1.57, 95% CI 1.05-2.35), heart failure (adjusted OR 1.66, 95% CI 1.35-2.03) and DM-HF-Pulm subgroups (adjusted OR 1.35, 95% CI 1.12-1.61), and lower in the diabetes subgroup (adjusted OR 0.67, 95% CI 0.50-0.89), compared with the low comorbidity group.

Interpretation: Patients admitted to hospital with CAP cluster into clinically recognizable subgroups based on coexisting conditions. Clinical care and outcomes vary among these subgroups with little evidence to guide decision-making, highlighting opportunities for research to personalize care.

Background: Primordial prevention may be a relevant strategy for the prevention of cancer. Given the commonality of risk factors and mechanisms between cancer and cardiovascular disease, we examined the associations between the number of ideal cardiovascular health metrics in midlife and incident cancer.

Methods: In 3 European cohorts (NutriNet-Santé and GAZEL, France; Whitehall II, United Kingdom), the number of ideal cardiovascular health metrics was determined at baseline (range 0-7). Follow-up for cancer events was until October 2020 (NutriNet-Santé), March 2017 (Whitehall II) and December 2015 (GAZEL). Cox regression was conducted in each cohort, and results were thereafter pooled using a random-effects model.

Results: Data were available on 39 718 participants. A total of 16 237 were from NutriNet-Santé (mean age 51.3 yr; 28% men), 9418 were from Whitehall II (mean age 44.8 yr; 68% men) and 14 063 were from GAZEL (mean age 45.2 yr; 75% men). The median follow-up was 8.1 years in NutriNet-Santé, 29.6 years in Whitehall II and 24.8 years in GAZEL, and yielded a total of 4889 cancer events. A greater number of ideal cardiovascular health metrics was associated with a lower overall cancer risk in each cohort, with an aggregate hazard ratio (HR) per 1 increment in number of ideal metrics of 0.91 (95% confidence interval [CI] 0.88-0.93). This association remained after removal of the smoking metric (aggregate HR per unit increment in number of ideal metrics: 0.94, 95% CI 0.90-0.97), and site-specific analysis demonstrated a significant association with lung cancer.

Interpretation: A greater number of ideal cardiovascular health metrics in midlife was associated with lower cancer risk, notably lung cancer. Primordial prevention of cardiovascular risk factors in midlife may be a complementary strategy to prevent the onset of cancer.

Background: Clinical guidelines for hypertension were updated with lower blood pressure targets following new studies in 2015; the real-world impact of these changes on antihypertensive drug use is unknown. We aimed to describe trends in antihypertensive drug utilization from 2004 to 2019 in British Columbia.

Methods: We conducted a longitudinal study to describe the annual prevalence and incidence rate of use of 5 antihypertensive drug classes (thiazides, angiotensin-converting enzyme [ACE] inhibitors, angiotensin II receptor blockers [ARBs], calcium channel blockers and β-blockers) among BC residents aged 30-75 years. We also conducted a cohort study to compare the risk of discontinuation and switch or add-on therapy between incident users of the above drug classes. We used linkable administrative health databases from BC. We performed a Fine-Gray competing risk analysis to estimate subhazard ratios.

Results: Among BC residents aged 30-75 years (population: 2 376 282 [2004] to 3 014 273 [2019]), the incidence rate of antihypertensive drug use decreased from 23.7 per 1000 person-years in 2004 to 18.3 per 1000 person-years in 2014, and subsequently increased to 22.6 per 1000 person-years in 2019. The incidence rate of thiazide use decreased from 8.9 per 1000 person-years in 2004 to 3.2 per 1000 person-years in 2019, and incidence rates for the other drug classes increased. Incident users receiving thiazide monotherapy had an increased risk of discontinuing any antihypertensive treatment compared with ACE inhibitor monotherapy (subhazard ratio 0.96, 95% confidence interval [CI] 0.95-0.97), ARB monotherapy (subhazard ratio 0.84, 95% CI 0.81-0.87) and thiazide combination with ACE inhibitor or ARB (subhazard ratio 0.86, 95% CI 0.84-0.88), and had the highest risk of switching or adding on.

Interpretation: First-line use of thiazides continued to decrease despite a marked increase in incident antihypertensive therapy following updated guidelines; incident users receiving ARB monotherapy were least likely to discontinue, and incident users receiving thiazide monotherapy were more likely to switch or add on than users of other initial monotherapy or combination. Further research is needed on the factors influencing treatment decisions to understand the differences in trends and patterns of antihypertensive drug use.

Background: Most prescriptions for sedative-hypnotics are written by family physicians. Given the influence of preceptors on residents' prescribing, this study explored how family physician preceptors manage sleeping problems.

Methods: Family physician preceptors affiliated with a postgraduate training program in Alberta were invited to participate in this mixed-methods study, conducted from January to October 2021. It included a quantitative survey of preceptors' attitudes to treatment options for sleep disorder, perceptions of patient expectations and self-efficacy beliefs. Participants indicated their responses on a 5-point Likert scale ranging from "strongly disagree" to "strongly agree." Respondents were then asked whether they were interested in participating in a semistructured qualitative interview that elicited preceptors' management of sleep disorder in response to a series of vignettes. We analyzed the quantitative data using descriptive statistics and the qualitative interviews using thematic analysis.

Results: Of the 76 preceptors invited to participate, 47 (62%) completed the survey, and 10 were interviewed. Thirty-two survey respondents (68%) were in academic teaching clinics, and 15 (32%) were from community clinics. The majority of participants (34 [72%]) agreed they had sufficient expertise to use nondrug treatment. Most (43 [91%]) had made efforts to reduce prescribing, and 45 (96%) felt able to support patients empathically when not using sleeping medication. The qualitative data showed that management of sleeping disorder was emotionally challenging. Participants hesitated to prescribe sedatives and reported "exceptions" to prescribing, many of which included indications within guideline recommendations. Participants were reluctant to change a colleague's management.

Interpretation: Preceptors were confident using nonpharmacologic management to treat sleep disorder and hesitant to use sedative-hypnotics, presenting legitimate use of sedatives as exceptional behaviour. Acknowledging social norms and affective aspects involved in prescribing may support balanced prescribing of sedative-hypnotics for sleep disorder and reduce physician anxiety.

Background: Many health systems struggle with delayed discharges (known as alternate level of care [ALC] in Canada). Our objectives were to describe and compare patient and hospitalization characteristics by ALC status, and to examine the impact of the initial period of the COVID-19 pandemic on ALC rates in Ontario, Canada.

Methods: We conducted an interrupted time series using linked administrative data for acute care hospital discharges in Ontario between Feb. 28, 2018, and Nov. 30, 2020. We measured the monthly ALC rate among discharges before and after the onset of the COVID-19 pandemic (Mar. 1, 2020). We used interrupted time series regressions to examine the association between the onset of the pandemic and average ALC monthly rates.

Results: We identified no meaningful differences in patient and admission characteristics, irrespective of time; however, differences were identified by ALC status. The overall average monthly rate of ALC discharges before the COVID-19 pandemic was 4.9% and after the onset of the pandemic was 5.0%. These discharges dropped to 4.3% (n = 3558) in March 2020 but then rebounded to their peak of 5.8% (n = 3915). There was no significant change in the average level of ALC rates per month after the onset of the pandemic (increase of 0.36% average per month, 95% confidence interval [CI] -0.11% to 0.83%) or monthly rate of change (slope) after the onset of the pandemic (-0.08%, 95% CI -0.15 to 0).

Interpretation: We identified a continued high rate of hospital discharges with an ALC component despite the considerable efforts in hospital to reduce hospital occupancy during the COVID-19 pandemic. Future research should examine why ALC rates remain high despite hospital efforts.

Background: Patients with scleroderma require a lifetime of treatment and frequent contacts with rheumatologists and other health care professionals. Although publicly funded health care systems in Canada cover many costs, patients may still face a substantial financial burden in accessing care. The purpose of this study was to quantify out-of-pocket costs borne by people with scleroderma in Canada and compare this burden for those living in large communities and smaller communities.

Methods: We analyzed responses to a Web-based survey of people living in Canada with scleroderma. Respondents reported annual out-of-pocket medical, travel and accommodation and other nonmedical costs (2019 Canadian dollars). We used descriptive statistics to describe travel distance and out-of-pocket costs. We used a 2-part model to estimate the impact on out-of-pocket costs of living in a large urban centre (≥ 100 000 population), compared with smaller urban centres or rural areas (< 100 000 population). We generated combined mean estimates from the 2-part models using predictive margins.

Results: The survey included 120 people in Canada with scleroderma. The mean, annual, total out-of-pocket costs were $3357 (standard deviation $5580). Respondents living in smaller urban centres and rural areas reported higher mean total costs ($4148, 95% confidence interval [CI] $3618-$4680) and travel or accommodation costs ($1084, 95% CI $804-$1364) than those in larger urban centres (total costs $2678, 95% CI $2252-$3104; travel or accommodation costs $332, 95% CI $207-$458).

Interpretation: Many patients with scleroderma incur considerable out-of-pocket costs, and this burden is exacerbated for those living in smaller urban centres and rural areas. Health care systems and providers should consider ways to alleviate this burden and support equitable access to care.

Background: Antimicrobial resistance is a rising threat to human health, and, with up to 90% of antibiotics prescribed in the community, it is critical to examine Canadian antibiotic stewardship practices in outpatient settings. We carried out a large-scale analysis of appropriateness in community-based prescribing of antibiotics to adults in Alberta, reporting on 3 years of data from physicians practising in the province.

Methods: The study cohort was composed of all adult (age 18-65 yr) Alberta residents who filled at least 1 antibiotic prescription written by a community-based physician between Apr. 1, 2017, and Mar. 6, 2020. We linked diagnosis codes from the clinical modification of the International Classification of Diseases, 9th Revision (ICD-9-CM), as used for billing purposes by the province's fee-for-service community physicians, to drug dispensing records, as maintained in the province's pharmaceutical dispensing database. We included physicians practising in community medicine, general practice, generalist mental health, geriatric medicine and occupational medicine. Following an approach used in previous research, we linked diagnosis codes with antibiotic drug dispensations, classified across a spectrum of appropriateness (always, sometimes never, no diagnosis code).

Results: We identified 3 114 400 antibiotic prescriptions dispensed to 1 351 193 adult patients by 5577 physicians. Of these prescriptions, 253 038 (8.1%) were "always appropriate," 1 168 131 (37.5%) were "potentially appropriate," 1 219 709 (39.2%) were "never appropriate," and 473 522 (15.2%) were not associated with an ICD-9-CM billing code. Among all dispensed antibiotic prescriptions, amoxicillin, azithromycin and clarithromycin were the most commonly prescribed drugs labelled "never appropriate."

Interpretation: We found that nearly 40% of prescriptions dispensed to 1.35 million adult patients in Alberta's community-based settings over a 35-month period were inappropriate. This finding suggests that additional policies and programs to improve stewardship among physicians prescribing antibiotics for adult outpatients in Alberta may be warranted.

Background: In Canada, endoscopy is primarily performed by gastroenterologists and surgeons, and some studies report that colonoscopies performed by nongastroenterologists have more complications and higher rates of future colorectal cancer. Our objective was to determine whether rural-based nongastroenterologist endoscopists are achieving quality benchmarks in colonoscopy.

Methods: This quality improvement initiative prospectively evaluated 6 key performance indicators (KPIs) (cecal intubations, polyp detection [males and females; for first-time colonoscopies on patients aged ≥ 50 yr], bowel preparations, patient comfort and withdrawal times) on consecutive colonoscopies performed by participating Alberta North Zone endoscopists. The study period was June 2018 to March 2020. Overall and individual endoscopist's KPIs were compared with standard benchmarks. Additional performance indicators included mean number of polyps per colonoscopy and an exploration of study-defined sedation-related level of consciousness.

Results: Data were collected on 6212 colonoscopies performed by 16 endoscopists (9 surgeons, 5 family physicians and 2 internists) in 6 hospitals. All 6 KPI benchmarks were achieved when results were pooled over all endoscopists in the study. Overall, cecal intubation occurred in 6006 of 6209 (96.7%, 95% confidence interval 94.5%-99.0%) cases. Polyp detection was 65.9% (592/898) and 49.8% (348/699) for male and female patients, respectively, aged 50 years or older. Variability in individual endoscopist results existed, especially for the mean number of polyps per 100 colonoscopies and sedation-related level of consciousness.

Interpretation: Overall, Alberta North Zone endoscopists are performing high-quality colonoscopies, collectively achieving all 6 KPIs. To understand endoscopic performance and encourage individual and group reflection on endoscopic practices, Canadian endoscopists are encouraged to participate in similar colonoscopy quality initiative studies.