Quality of antibiotic prescribing for pediatric community-acquired Pneumonia in outpatient care.

BACKGROUND: Antibiotics remain the primary treatment for community acquired pneumonia (CAP), however rising rates of antimicrobial resistance may jeopardize their future efficacy. With higher rates of disease reported in the youngest populations, effective treatment courses for pediatric pneumonia are of paramount importance. This study is the first to examine the quality of pediatric antibiotic use by agent, dose and duration. METHODS: A retrospective cohort study included all outpatient/primary care physician visits for pediatric CAP (aged < 19 years) between January 1 2014 to December 31 2018. Relevant practice guidelines were identified, and treatment recommendations extracted. Amoxicillin was the primary first-line agent for pediatric CAP. Categories of prescribing included: guideline adherent, effective but unnecessary (excess dose and/or duration), under treatment (insufficient dose and/or duration), and not recommended. Proportions of attributable-antibiotic use were examined by prescribing category, and then stratified by age and sex. RESULT(S): A total of 42,452 episodes of pediatric CAP were identified. Of those, 31,347 (76%) resulted in an antibiotic prescription. Amoxicillin accounted for 51% of all prescriptions. Overall, 27% of prescribing was fully guideline adherent, 19% effective but unnecessary, 10% under treatment, and 44% not recommended by agent. Excessive duration was the hallmark of effective but unnecessary prescribing (97%) Macrolides accounted for the majority on non-first line agent use, with only 32% of not recommended prescribing preceded by a previous course of antibiotics. CONCLUSION(S): This study is the first in Canada to examine prescribing quality for pediatric CAP by agent, dose and duration. Utilizing first-line agents, and shorter-course treatments are targets for stewardship.

Models of shared care for the management of psychotic disorder after first diagnosis in Ontario.

OBJECTIVE: To describe the provision of care for young people following first diagnosis of psychotic disorder. DESIGN: Retrospective cohort study using health administrative data. SETTING: Ontario. PARTICIPANTS: People aged 14 to 35 years with a first diagnosis of nonaffective psychotic disorder in Ontario between 2005 and 2015 (N=39,449). MAIN OUTCOME MEASURES: Models of care, defined by psychosis-related service contacts with primary care physicians and psychiatrists during the 2 years after first diagnosis of psychotic disorder. RESULTS: During the 2-year follow-up period, 29% of the cohort received only primary care, 30% received only psychiatric care, and 32% received both primary and psychiatric care (shared care). Among the shared care group, 72% received care predominantly from psychiatrists, 20% received care predominantly from primary care physicians, and 9% received approximately equal care from psychiatry and primary care. Variation in patient and physician characteristics was observed across the different models of care. CONCLUSION: One in 3 young people with psychotic disorder received shared care during the 2-year period after first diagnosis. The findings highlight opportunities for increasing collaboration between primary care physicians and psychiatrists to enhance the quality of care for those with early psychosis.

Patient and Physician Factors Associated with First Diagnosis of Non-affective Psychotic Disorder in Primary Care.

Primary care physicians play a central role in pathways to care for first-episode psychosis, and their increased involvement in early detection could improve service-related outcomes. The aim of this study was to estimate the proportion of psychosis first diagnosed in primary care, and identify associated patient and physician factors. We used linked health administrative data to construct a retrospective cohort of people aged 14-35 years with a first diagnosis of non-affective psychosis in Ontario, Canada between 2005-2015. We restricted the sample to patients with help-seeking contacts for mental health reasons in primary care in the six months prior to first diagnosis of psychotic disorder. We used modified Poisson regression models to examine patient and physician factors associated with a first diagnosis of psychosis in primary care. Among people with early psychosis (n = 39,449), 63% had help-seeking contacts in primary care within six months prior to first diagnosis. Of those patients, 47% were diagnosed in primary care and 53% in secondary/tertiary care. Patients factors associated with lower likelihood of diagnosis in primary care included male sex, younger age, immigrant status, and comorbid psychosocial conditions. Physician factors associated with lower likelihood of diagnosis in primary care included solo practice model, urban practice setting, international medical education, and longer time since graduation. Our findings indicate that primary care is an important contact for help-seeking and diagnosis for a large proportion of people with early psychosis. For physicians less likely to diagnose psychosis in primary care, targeted resources and interventions could be provided to support them in caring for patients with early psychosis.

Bariatric Center Designation and Outcomes Following Repeat Abdominal Surgery in Bariatric Patients.

INTRODUCTION: Repeat abdominal surgery in the bariatric surgery patient population may be challenging for non-bariatric-accredited institutions. The impact of regionalized bariatric care on clinical outcomes for bariatric surgery patients requiring repeat abdominal surgery is currently unknown. This study aims to investigate the association between bariatric center designation and clinical outcomes following hepatobiliary, hernia, and upper and lower gastrointestinal operations among patients with prior bariatric surgery. METHODS: This is a cohort study of a large sample of Ontario residents who underwent primary bariatric surgery between 2010 and 2017. A comprehensive list of eligible abdominal operations was captured using administrative data. The primary outcome was 30-d complications. Secondary outcomes included 30-d mortality, readmission, and length of stay. RESULTS: Among the 3301 study patients, 1305 (40%) received their first abdominal reoperation following bariatric surgery at a designated bariatric center. Nonbariatric center designation was not associated with significantly higher rates of 30-d complications (5.73% versus 5.72%), mortality (0.80% versus 0.77%), readmissions (1.11% versus 1.85%), or median postoperative length of stay (4 versus 4 d). After grouping the category of reoperations, upper gastrointestinal (odds ratio [OR] 0.66, confidence interval [CI] 0.39-1.11) and abdominal wall hernia surgery (OR 0.52, CI 0.27-0.99) showed a lower adjusted OR for complications among bariatric centers. CONCLUSIONS: Our study demonstrates that after adjustment for case-mix and patient characteristics, bariatric surgery patients undergoing repeat abdominal surgery at nonbariatric centers is not associated with higher proportion of complications or mortality. Complex hernia surgery may be considered the most appropriate for referral.

Concussion in adolescence and the risk of multiple sclerosis: A retrospective cohort study.

BACKGROUND: Physical trauma, specifically concussions sustained during adolescence, has been hypothesized to be a risk factor for multiple sclerosis (MS). OBJECTIVE: To examine the association between adolescent concussions and future MS diagnosis. METHODS: This retrospective study using linked administrative databases from Ontario, Canada, identified 97,965 adolescents (age 11-18 years) who sustained ⩾1 concussion and presented to an emergency department between 1992 and 2011. Cases were matched 1:3 with individuals who had not sustained a concussion based on age, sex, address, and index date. The primary outcome was MS diagnosis, using a validated MS diagnosis definition: ⩾1 hospitalization or ⩾5 physician billings within 2 years. RESULTS: A concussion during adolescence was associated with a significantly increased risk of MS (hazard ratio (HR) = 1.29, p = 0.03). Sex-specific analysis revealed that only males who sustained a concussion in adolescence had a raised risk of MS (HR = 1.41, p = 0.04). CONCLUSION: This study supports an association between concussions in adolescence and future MS diagnoses, highlighting the potentially serious long-term effects of concussions.

Printed educational materials directed at Ontario family physicians do not improve adherence to guideline recommendations for diabetes management: a pragmatic, factorial, cluster randomized controlled trial [ISRCTN72772651].

BACKGROUND: Printed educational materials (PEMs) have long been used to inform clinicians on evidence-based practices. However, the evidence for their effects on patient care and outcomes is unclear. In Ontario, despite widely available clinical practice guidelines recommending antihypertensives and cholesterol-lowering agents for patients with diabetes, prescriptions remain low. We aimed to determine whether PEMs can influence physicians to intensify prescribing of these medications. METHODS: A pragmatic, 2 × 2 factorial, cluster randomized controlled trial was designed to ascertain the effect of two PEM formats on physician prescribing: a postcard-sized message ("outsert") or a longer narrative article ("insert"). Ontario family physician practices (clusters) were randomly allocated to receive the insert, outsert, both or neither. Physicians were eligible if they were in active practice and their patients were included if they were over 65 years with a diabetes diagnosis; both were unaware of the trial. Administrative databases at ICES (formerly the Institute for Clinical Evaluative Sciences) were used to link patients to their physician and to analyse prescribing patterns at baseline and 1 year following PEM mailout. The primary outcome was intensification defined as the addition of a new antihypertensive or cholesterol-lowering agent, or dose increase of a current drug, measured at the patient level. Analyses were by intention-to-treat and accounted for the clustering of patients to physicians. RESULTS: We randomly assigned 4231 practices (39% of Ontario family physicians) with a total population of 185,526 patients (20% of patients with diabetes in Ontario primary care) to receive the insert, outsert, both, and neither; among these, 4118 practices were analysed (n = 1025, n = 1037, n = 1031, n = 1025, respectively). No significant treatment effect was found for the outsert (odds ratio (OR) 1.01, 95% confidence interval (CI) 0.98 to 1.04) or the insert (OR 0.99, 95% CI 0.96 to 1.02). Percent of intensification in the four arms was similar (approximately 46%). Adjustment for physician characteristics (e.g., age, sex, practice location) had no impact on these findings. CONCLUSIONS: PEMs have no effect on physician's adherence to recommendations for the management of diabetes-related complications in Ontario. Further research should investigate the effect of other strategies to narrow this evidence-to-practice gap. TRIAL REGISTRATION: ISRCTN72772651 . Retrospectively registered 21 July 2005.

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.

Retrospective cohort analysis of outpatient antibiotic prescribing for community-acquired pneumonia in Canadian older adults.

BACKGROUND: This retrospective cohort study is the first in North America to examine population-level appropriate antibiotic use for community-acquired pneumonia (CAP) in older adults, by agent, dose and duration. With the highest rates of CAP reported in the elderly populations, appropriate antibiotic use is essential to improve clinical outcomes. Given the ongoing crisis of antimicrobial resistance, understanding inappropriate antibiotic prescribing is integral to direct community stewardship efforts. METHODS: All outpatient primary care visits for CAP (aged ≥65 years) were identified using physician billing codes between January 1 2014 to December 31 2018 in British Columbia (BC) and Ontario (ON). Categories of prescribing were derived from existing literature, and constructed for clinical relevance using Canadian and international guidelines available during the study period. Categories were mutually exclusive and included: guideline adherent (first-line agent, adherent dose/duration), clinically appropriate (non-first line agent, presence of comorbidities), effective but unnecessary (first-line agent, excess dose/duration), undertreatment (first-line agent, subtherapeutic dose/duration), and not recommended (non-first line agent, absence of comorbidities). Proportions of prescribing were examined by category. Temporal trends in prescribing were examined using Poisson regression. RESULTS: A total of 436,441 episodes of CAP were identified, with 46% prescribed an antibiotic in BC, and 52% in Ontario. Guideline adherent prescribing was minimal for both provinces (BC: 2%; ON: 1%) however the largest magnitude of increase was reported in this category by the final study year (BC-Rate Ratio [RR]: 3.4, 95% Confidence Interval [CI]: 2.7-4.3; ON-RR: 4.62, 95% CI: 3.4-6.5). Clinically appropriate prescribing accounted for the most antibiotics issued, across all study years (BC: 61%; ON: 74%) (BC-RR: 0.8, 95% CI: 0.8-0.8; ON-RR: 0.9, 95% CI: 0.8-0.9). Excess duration of therapy was the hallmark characteristic for effective but unnecessary prescribing (BC: 92%; ON: 99%). The most common duration prescribed was 7 days, followed by 10. Not recommended prescribing was minimal in both provinces (BC: 4%; ON: 7%) and remained stable by the final study year (BC-RR: 1.1, 95% CI: 0.9-1.2; ON-RR: 0.9, 95% CI: 0.9-1.1). CONCLUSION: Three quarters of antibiotic prescribing for CAP was appropriate in Ontario, but only two thirds in BC. Shortening durations-in line with evidence for 3 to 5-day treatment presents a focused target for stewardship efforts.

Access to a regular primary care physician among young people with early psychosis in Ontario, Canada.

AIM: Access to a primary care physician in early psychosis facilitates help-seeking and engagement with psychiatric treatment. We examined access to a regular primary care physician in people with early psychosis, compared to the general population, and explored factors associated with access. METHODS: Using linked health administrative data from Ontario (Canada), we identified people aged 14-35 years with a first diagnosis of nonaffective psychotic disorder (n = 39 449; 2005-2015). We matched cases to four randomly selected general population controls based on age, sex, neighbourhood, and index date (n = 157 796). We used modified Poisson regression to estimate prevalence ratios (PR) for access to a regular primary care physician in the year prior to first diagnosis of psychotic disorder, and the sociodemographic and clinical factors associated with access. RESULTS: A larger proportion of people with early psychosis had a regular primary care physician, relative to the general population (89% vs. 68%; PR = 1.30, 95%CI = 1.30-1.31). However, this was accounted for by a higher prevalence of comorbidities among people with psychosis, and this association was no longer present after adjustment (PR = 0.97, 95%CI = 0.97, 0.98). People with early psychosis who were older, male, refugees and those residing in lower income or high residential instability neighbourhoods were less likely to have a regular primary care physician. CONCLUSION: Approximately one in ten young people with early psychosis in Ontario lack access to a regular primary care physician. Strategies to improve primary care physician access are needed for management of physical comorbidities and to ensure continuity of care.

Risk factors for abdominal reoperations in bariatric patients.

BACKGROUND: With a growing bariatric population, a better understanding of the patient and health provider-related factors associated with later reoperations could help providers enhance follow-up and develop reliable benchmarking targets. OBJECTIVES: To investigate the patient and provider-related risk factors associated with abdominal reoperations in bariatric patients. SETTING: This is a cohort study using data from a large clinical registry of Ontario bariatric patients between 2010 and 2016. METHODS: A multilevel mixed effect logistic regression model using hospital and surgeon identifiers as random effects was performed to adjust for clustering of patients. The primary outcome was any abdominal operation performed within 2 years of primary bariatric surgery. RESULTS: Among a cohort of 10,946 bariatric patients (86.6% receiving gastric bypass surgery), 15.8% underwent an abdominal operation within 2 years and about a third of these were urgent. The multilevel analysis demonstrated that 98% of patient variation among reoperations was a result of patient characteristics rather than disparities between surgeons or center experience. Type of procedure was not a significant factor after adjustment for surgeon and hospital level experience (OR [odds ratio] .85, 95% CI [confidence interval] .70-1.03). Concurrent abdominal wall (OR 2.40, 95% CI 1.26-4.59), hiatal hernia repairs (OR 1.29, 95% CI 1.02-1.62), and previously higher health care users (OR 1.30, 95% CI 1.15-1.46) were most significantly associated with reoperations. CONCLUSION: Reoperations are significantly more common among certain bariatric patients, especially those undergoing concurrent hernia procedures. Reoperations were not associated with provider-related factors and may not be a suitable target for health provider benchmarking.

Validity of Hospital Codes for Obesity in Ontario, Canada.

BACKGROUND: Obesity has a significant impact on population health and health care. Administrative databases may be a useful tool to study obesity at a population level. In this work, we aimed to determine the validity of hospital codes for obesity in Ontario, Canada. METHODS: Using linked health-care databases (ICES), we conducted a validation study in adults ≥18 years of age who had their height and weight recorded during a hospitalization in southwestern Ontario. We considered a body mass index ≥30 kg/m2 as our gold standard definition for obesity. We then examined the validity of 2 International Classification of Diseases---10th revision (ICD-10) coding algorithms for obesity (Algorithm 1, ICD-10 E66.X; and Algorithm 2, ICD-10 E65.X-68.X). As additional analyses, we examined the validity of algorithms in different obesity classes (i.e. obese classes 1, 2 and 3), and in patients with diagnosed diabetes and hypertension. RESULTS: There were 34,588 patients included in our study (mean age, 62 years; 47% female). Algorithm 1 performed best, with a sensitivity, specificity, positive predictive value and negative predictive value of 8.8%, 99.8%, 95.4% and 65.1%, respectively. The sensitivity of this algorithm was highest in patients with obesity class 3 (27.4%) and in those with diagnosed diabetes. CONCLUSIONS: Hospital codes for obesity have a high positive predictive value and specificity. These codes can be used to build and study cohorts of patients with obesity in administrative database studies. However, given their limited sensitivity, administrative codes provide inaccurate incidence and prevalence estimates.

A Retrospective Cohort Study of Healthcare Utilization Associated with Paravertebral Blocks for Chronic Pain Management in Ontario.

Background: Injections, particularly paravertebral blocks (PVBs), are frequently performed procedures in Ontario, Canada, for the management of chronic pain, despite limited evidence and risk of complications. Aim: This study examines usage patterns of PVBs to evaluate their effects on healthcare utilization and opioid prescribing. Methods: A retrospective cohort study in Ontario using administrative data. Ontario residents receiving their initial PVBs between July 1, 2013 and March 31, 2018 were included. Changes in use of other interventions, physician visits, and opioids were compared to the 12-month periods before and after index PVBs. Data use was authorized under section 45 of Ontario's Personal Health Information Protection Act. Results: 47,723 patients received their initial PVBs in the study period. The rate of index PVBs increased from 1.61 per 10,000 population (2013) to 2.26 per 10,000 (2018). Initial PVBs were performed most commonly by family physicians (N = 25,042), followed by anesthesiologists (N = 14,195). 23,386 patients (49%) received 1 to 9 repeat PVBs in the 12 months after index PVB; 12,474 patients (26.15%) received 10 or more. Use of other nonimage guided interventional pain procedures per patient (mean±SD) increased from 2.19 ± 9.35 to 31.68 ± 52.26 in the year before and after index PVB. Relevant physician visits per patient (mean±SD) also increased from 2.92 ± 3.61 to 9.64 ± 11.77. Mean opioid dosing did not change significantly between the year before and the year after index PVB. Conclusion: PVBs are associated with increases in healthcare utilization and no change in opioid use patterns.

Contexte: Les injections, en particulier les blocs paravertébraux (BPV), sont des procédures fréquemment effectuées en Ontario, Canada, pour la prise en charge de la douleur chronique, malgré des données probantes limitées et le risque de complications.Objectif: Cette étude examine les modes d'utilisation des BPV afin d'évaluer leurs effets sur l'utilisation des soins de santé et la prescription d'opioïdes.Méthodes: Étude de cohorte rétrospective utilisant les données administratives en Ontario. Les résidents de l'Ontario ayant reçu leur BPV initial entre le 1er juillet 2013 et le 31 mars 2018 ont été inclus. Les changements dans l'utilisation des autres interventions, les visites aux médecins et les opioïdes ont été comparés 12 mois avant et 12 mois après les BPV de référence. L'utilisation des données a été autorisée en vertu de la Loi sur la protection des renseignements personnels sur la santé de l'Ontario.Résultats: 47 723 patients ont reçu leur BPV initial au cours de la période étudiée. Le taux de BPV est passé de 1,61 pour 10 000 habitants (2013) à 2,26 pour 10 000 (2018). Les BPV de référence étaient effectués le plus souvent par des médecins de famille (N = 25 042), suivis par les anesthésistes (N = 14 195). 23 386 patients (49 %) ont reçu de 1 à 9 BPV répétés dans les 12 mois suivant le BPV de référence ; 12 474 patients (26,15 %) en ont reçu 10 ou plus. L'utilisation d'autres procédures interventionnelles pour la douleur non guidées par l'image par patient (moyenne ± ET) est passée de 2,19 ± 9,35 à 31,68 ± 52,26 l'année précédant et suivant le BPV. Les visites médicales pertinentes par patient (moyenne ± ET) ont également augmenté de 2,92 ± 3,61 à 9,64 ± 11,77. La dose moyenne d'opioïdes n'a pas changé de manière significative entre l'année précédant et suivant le BPV de référence.Conclusion: Les BPV sont associés à une augmentation de l'utilisation des soins de santé et ne sont associés à aucun changement dans les modes d'utilisation des opioïdes.

Effect of electronic medication reconciliation at the time of hospital discharge on inappropriate medication use in the community: an interrupted time-series analysis.

BACKGROUND: It is unclear if enhanced electronic medication reconciliation systems can reduce inappropriate medication use and improve patient care. We evaluated trends in potentially inappropriate medication use after hospital discharge before and after adoption of an electronic medication reconciliation system. METHODS: We conducted an interrupted time-series analysis in 3 tertiary care hospitals in London, Ontario, using linked health care data (2011-2019). We included patients aged 66 years and older who were discharged from hospital. Starting between Apr. 13 and May 21, 2014, physicians were required to complete an electronic medication reconciliation module for each discharged patient. As a process outcome, we evaluated the proportion of patients who continued to receive a benzodiazepine, antipsychotic or gastric acid suppressant as an outpatient when these medications were first started during the hospital stay. The clinical outcome was a return to hospital within 90 days of discharge with a fall or fracture among patients who received a new benzodiazepine or antipsychotic during their hospital stay. We used segmented linear regression for the analysis. RESULTS: We identified 15 932 patients with a total of 18 405 hospital discharge episodes. Before the implementation of the electronic medication reconciliation system, 16.3% of patients received a prescription for a benzodiazepine, antipsychotic or gastric acid suppressant after their hospital stay. After implementation, there was a significant and immediate 7.0% absolute decline in this proportion (95% confidence interval [CI] 4.5% to 9.5%). Before implementation, 4.1% of discharged patients who newly received a benzodiazepine or antipsychotic returned to hospital with a fracture or fall within 90 days. After implementation, there was a significant and immediate 2.3% absolute decline in this outcome (95% CI 0.3% to 4.3%). INTERPRETATION: Implementation of an electronic medication reconciliation system in 3 tertiary care hospitals reduced potentially inappropriate medication use and associated adverse events when patients transitioned back to the community. Enhanced electronic medication reconciliation systems may allow other hospitals to improve patient safety.

Appropriateness of Outpatient Antibiotic Use in Seniors across Two Canadian Provinces.

Antimicrobials are among the most prescribed medications in Canada, with over 90% of antibiotics prescribed in outpatient settings. Seniors prescribed antimicrobials are particularly vulnerable to adverse drug events and antimicrobial resistance. The extent of inappropriate antibiotic prescribing in outpatient Canadian medical practice, and the potential long-term trends in this practice, are unknown. This study is the first in Canada to examine prescribing quality across two large-scale provincial healthcare systems to compare both quantity and quality of outpatient antibiotic use in seniors. Population-based analyses using administrative health databases were conducted in British Columbia (BC) and Ontario (ON), and all outpatient, oral antimicrobials dispensed to seniors (≥65 years) from 1 January 2000 to 31 December 2018 were identified. Antimicrobials were linked to an indication using a 3-tiered hierarchy. Tier 1 indications, which always require antibiotics, were given priority, followed by Tier 2 indications that sometimes require antibiotics, then Tier 3, which never require antibiotics. Prescription rates were calculated per 1000 population, and trends were examined overall, by drug class, and by patient demographics. Prescribing remained steady in both provinces, with 11,166,401 prescriptions dispensed overall in BC, and 27,656,014 overall in ON. BC prescribed at slightly elevated rates (range: 790 to 930 per 1000 residents), in comparison to ON (range: 745 to 785 per 1000 residents), throughout the study period. For both provinces, a Tier 3 diagnosis was the most common reason for antibiotic use, accounting for 50% of all indication-associated antibiotic prescribing. Although Tier 3 indications remained the most prescribed-for diagnoses throughout the study period, a declining trend over time is encouraging, with much room for improvement remaining. Elevated prescribing to seniors continues across Canadian outpatient settings, and prescribing quality is of high concern, with 50% of all antimicrobials prescribed inappropriately for common infections that do not require antimicrobials.

Retrospective cohort study of healthcare utilization and opioid use following radiofrequency ablation for chronic axial spine pain in Ontario, Canada.

BACKGROUND AND OBJECTIVES: Radiofrequency ablation (RFA) is a common treatment modality for chronic axial spine pain. Controversy exists over its effectiveness, and outcomes in a real-world setting have not been evaluated despite increasing use of RFA. This study examined changes in healthcare utilization and opioid use after RFA in Ontario, Canada. METHODS: This retrospective cohort study was conducted in Ontario using administrative data. Ontario residents receiving their initial RFA between 1 January 2009 and 31 March 2015 were included. Physician visits, spinal injections, and opioid dosing/prescriptions in the 12-month periods before and after RFA were compared. RESULTS: The study included 4653 patients. The number of RFA procedures significantly increased from 2009 to 2014 (22.5 cases/1 000 000 person-years to 82.5 cases/1 000 000 person-years). 4465 patients had at least one physician visit pre-RFA; there was a significant 23.89% reduction in physician visits post-RFA (pre-RFA: 29 616 visits; post-RFA: 22 542 visits). All reviewed specialties demonstrated a decrease in physician visits post-RF except neurosurgery. 3445 (85.70%) fewer spinal interventions for axial pain (medial/lateral branch blocks, facet/sacroiliac injections) were performed post-RFA. Significantly fewer epidurals were also performed post-RFA. 198 of 1007 patients (19.66%) on the Ontario Drug Benefit who received opioids pre-RFA did not require a postprocedure opioid prescription. Mean opioid dosing was unchanged post-RFA. CONCLUSIONS: Healthcare utilization was significantly reduced in the 12 months following RFA, and some patients eliminated opioid use. Selection criteria for RFA are not standardized in Ontario, and appropriate use guidelines for spine interventions may improve outcomes and reduce unnecessary procedures.

Secondary surgical intervention after primary glaucoma filtration surgery: an Ontario population-based study.

OBJECTIVE: To identify factors associated with secondary surgical intervention after glaucoma filtration surgery. DESIGN: Population-based retrospective cohort. METHODS: Patient records with billing claims for a primary glaucoma filtration surgery occurring between April 2003 and March 2015 were identified. Each identified record was examined for instances of secondary glaucoma surgeries within the patient's first postoperative year. Baseline characteristics of patients who required secondary surgical intervention were compared with those who did not. A multivariable Cox proportional hazards model was used to calculate hazard ratios. RESULTS: Within a cohort of 10,097 patients, 349 (3.46%) underwent a secondary surgical intervention within the first postoperative year. Interventions were less frequent after surgeries that included an indwelling drainage device (HR=0.58 95% CI, 0.37-0.89), phacoemulsification (HR=0.33, 0.21-0.52), or both (HR=0.09, 0.03-0.31). Patients with preoperative aminoglycoside and mydriatic exposure had significantly increased risk of secondary surgical intervention (HR=3.19, 1.89-5.36) and (HR=2.32, 1.49-3.61). Patients who underwent surgery on their contralateral eye experienced secondary surgical interventions more frequently: 7.44 per 10,000 person-days (versus 1.18 per 10,000 person-days, p < 0.0001). No significant differences in the rates of secondary surgical intervention were observed for patients taking different classes of glaucoma medications or those exposed to higher amounts of benzalkonium chloride. CONCLUSIONS: In Ontario, the overall rates of secondary surgical interventions in the first postoperative year are low but significantly higher in certain patient populations. Further work is required to address the higher rate of secondary surgical intervention in patients with a history of certain perioperative eye drop medications and those who require sequential-bilateral procedures.

Effects of Transmission Bottlenecks on the Diversity of Influenza A Virus.

We investigate the fate of de novo mutations that occur during the in-host replication of a pathogenic virus, predicting the probability that such mutations are passed on during disease transmission to a new host. Using influenza A virus as a model organism, we develop a life-history model of the within-host dynamics of the infection, deriving a multitype branching process with a coupled deterministic model to capture the population of available target cells. We quantify the fate of neutral mutations and mutations affecting five life-history traits: clearance, attachment, budding, cell death, and eclipse phase timing. Despite the severity of disease transmission bottlenecks, our results suggest that in a single transmission event, several mutations that appeared de novo in the donor are likely to be transmitted to the recipient. Even in the absence of a selective advantage for these mutations, the sustained growth phase inherent in each disease transmission cycle generates genetic diversity that is not eliminated during the transmission bottleneck.

SARS-CoV-2 Testing and Complications Across 6 Waves of the COVID-19 Pandemic Among Individuals Recently Experiencing Homelessness in Ontario, Canada.

This cohort study compares the rates of SARS-CoV-2 testing and complications across 6 waves of the COVID-19 pandemic in Ontario, Canada, between individuals recently experiencing homelessness, low-income residents, and the general population.

The rationale for probiotics improving reproductive health and pregnancy outcome.

PROBLEM: Medical problems of most importance to reproductive health of women differ to some extent between the developed world and resource-disadvantaged countries. Nevertheless, many share a common link in microbial involvement. METHOD OF STUDY: A review of the peer-reviewed literature on microbiota, probiotics, and reproductive health. RESULTS: Indigenous and probiotic lactobacilli express properties antagonistic to pathogens, but complementary to host immunity. These organisms are associated with conception, reducing the risk of infection, as well as potentially lowering the risk of a number of complications of pregnancy that otherwise lead to maternal and infant mortality and morbidity. CONCLUSIONS: The ability to manipulate the microbiome and to improve immunity through probiotics holds much promise. The lack of improvements over the past 40 years in managing urogenital infections in women is incomprehensible. Support for innovative diagnostic and treatment options is needed, including testing and implementing probiotic therapies, especially for women with poor access to healthcare and good nutrition.