Measuring waning protection from seasonal influenza vaccination during nine influenza seasons, Ontario, Canada, 2010/11 to 2018/19.

BackgroundWaning immunity from seasonal influenza vaccination can cause suboptimal protection during peak influenza activity. However, vaccine effectiveness studies assessing waning immunity using vaccinated and unvaccinated individuals are subject to biases.AimWe examined the association between time since vaccination and laboratory-confirmed influenza to assess the change in influenza vaccine protection over time.MethodsUsing linked laboratory and health administrative databases in Ontario, Canada, we identified community-dwelling individuals aged ≥ 6 months who received an influenza vaccine before being tested for influenza by RT-PCR during the 2010/11 to 2018/19 influenza seasons. We estimated the adjusted odds ratio (aOR) for laboratory-confirmed influenza by time since vaccination (categorised into intervals) and for every 28 days.ResultsThere were 53,065 individuals who were vaccinated before testing for influenza, with 10,264 (19%) influenza-positive cases. The odds of influenza increased from 1.05 (95% CI: 0.91-1.22) at 42-69 days after vaccination and peaked at 1.27 (95% CI: 1.04-1.55) at 126-153 days when compared with the reference interval (14-41 days). This corresponded to 1.09-times increased odds of influenza every 28 days (aOR = 1.09; 95% CI: 1.04-1.15). Individuals aged 18-64 years showed the greatest decline in protection against influenza A(H1N1) (aORper 28 days = 1.26; 95% CI: 0.97-1.64), whereas for individuals aged ≥ 65 years, it was against influenza A(H3N2) (aORper 28 days = 1.20; 95% CI: 1.08-1.33). We did not observe evidence of waning vaccine protection for individuals aged < 18 years.ConclusionsInfluenza vaccine protection wanes during an influenza season. Understanding the optimal timing of vaccination could ensure robust protection during seasonal influenza activity.

Evaluating the Impact of Statin Use on Influenza Vaccine Effectiveness and Influenza Infection in Older Adults.

BACKGROUND: Older adults are recommended to receive influenza vaccination annually, and many use statins. Statins have immunomodulatory properties that might modify influenza vaccine effectiveness (VE) and alter influenza infection risk. METHODS: Using the test-negative design and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against laboratory-confirmed influenza among community-dwelling statin users and nonusers aged ≥66 years during the 2010-2011 to 2018-2019 influenza seasons. We also estimated the odds ratio for influenza infection comparing statin users and nonusers by vaccination status. RESULTS: Among persons tested for influenza across the 9 seasons, 54 243 had continuous statin exposure before testing and 48 469 were deemed unexposed. The VE against laboratory-confirmed influenza was similar between statin users and nonusers (17% [95% confidence interval, 13%-20%] and 17% [13%-21%] respectively; test for interaction, P = .87). In both vaccinated and unvaccinated persons, statin users had higher odds of laboratory-confirmed influenza than nonusers (odds ratios for vaccinated and unvaccinated persons 1.15 [95% confidence interval, 1.10-1.21] and 1.15 [1.10-1.20], respectively). These findings were consistent by mean daily dose and statin type. VE did not differ between users and nonusers of other cardiovascular drugs, except for ß-blockers. We did not observe that vaccinated and unvaccinated users of these drugs had increased odds of influenza, except for unvaccinated ß-blocker users. CONCLUSIONS: Influenza VE did not differ between statin users and nonusers. Statin use was associated with increased odds of laboratory-confirmed influenza in vaccinated and unvaccinated persons, but these associations might be affected by residual confounding.

Hospitalizations During the COVID-19 Pandemic Among Recently Homeless Individuals: a Retrospective Population-Based Matched Cohort Study.

BACKGROUND: Hospitalizations fell precipitously among the general population during the COVID-19 pandemic. It remains unclear whether individuals experiencing homelessness experienced similar reductions. OBJECTIVE: To examine how overall and cause-specific hospitalizations changed among individuals with a recent history of homelessness (IRHH) and their housed counterparts during the first wave of the COVID-19 pandemic, using corresponding weeks in 2019 as a historical control. DESIGN: Population-based cohort study conducted in Ontario, Canada, between September 30, 2018, and September 26, 2020. PARTICIPANTS: In total, 38,617 IRHH, 15,022,368 housed individuals, and 186,858 low-income housed individuals matched on age, sex, rurality, and comorbidity burden. MAIN MEASURES: Primary outcomes included medical-surgical, non-elective (overall and cause-specific), elective surgical, and psychiatric hospital admissions. KEY RESULTS: Average rates of medical-surgical (rate ratio: 3.8, 95% CI: 3.7-3.8), non-elective (10.3, 95% CI: 10.1-10.4), and psychiatric admissions (128.1, 95% CI: 126.1-130.1) between January and September 2020 were substantially higher among IRHH compared to housed individuals. During the peak period (March 17 to June 16, 2020), rates of medical-surgical (0.47, 95% CI: 0.47-0.47), non-elective (0.80, 95% CI: 0.79-0.80), and psychiatric admissions (0.86, 95% CI: 0.84-0.88) were significantly lower among housed individuals relative to equivalent weeks in 2019. No significant changes were observed among IRHH. During the re-opening period (June 17-September 26, 2020), rates of non-elective hospitalizations for liver disease (1.41, 95% CI: 1.23-1.69), kidney disease (1.29, 95% CI: 1.14-1.47), and trauma (1.19, 95% CI: 1.07-1.32) increased substantially among IRHH but not housed individuals. Distinct hospitalization patterns were observed among IRHH even in comparison with more medically and socially vulnerable matched housed individuals. CONCLUSIONS: Persistence in overall hospital admissions and increases in non-elective hospitalizations for liver disease, kidney disease, and trauma indicate that the COVID-19 pandemic presented unique challenges for recently homeless individuals. Health systems must better address the needs of this population during public health crises.

Rates of health services use among residents of retirement homes in Ontario: a population-based cohort study.

BACKGROUND: Because there are no standardized reporting systems specific to residents of retirement homes in North America, little is known about the health of this distinct population of older adults. We evaluated rates of health services use by residents of retirement homes relative to those of residents of long-term care homes and other populations of older adults. METHODS: We conducted a retrospective cohort study using population health administrative data from 2018 on adults 65 years or older in Ontario. We matched the postal codes of individuals to those of licensed retirement homes to identify residents of retirement homes. Outcomes included rates of hospital-based care and physician visits. RESULTS: We identified 54 733 residents of 757 retirement homes (mean age 86.7 years, 69.0% female) and 2 354 385 residents of other settings. Compared to residents of long-term care homes, residents of retirement homes had significantly higher rates per 1000 person months of emergency department visits (10.62 v. 4.48, adjusted relative rate [RR] 2.61, 95% confidence interval [CI] 2.55 to 2.67), hospital admissions (5.42 v. 2.08, adjusted RR 2.77, 95% CI 2.71 to 2.82), alternate level of care (ALC) days (6.01 v. 2.96, adjusted RR 1.51, 95% CI 1.48 to 1.54), and specialist physician visits (6.27 v. 3.21, adjusted RR 1.64, 95% CI 1.61 to 1.68), but a significantly lower rate of primary care visits (16.71 v. 108.47, adjusted RR 0.13, 95% CI 0.13 to 0.14). INTERPRETATION: Residents of retirement homes are a distinct population with higher rates of hospital-based care. Our findings can help to inform policy debates about the need for more coordinated primary and supportive health care in privately operated congregate care homes.

Potential diabetes overtreatment and risk of adverse events among older adults in Ontario: a population-based study.

AIMS/HYPOTHESIS: More than 25% of older adults (age ≥75 years) have diabetes and may be at risk of adverse events related to treatment. The aim of this study was to assess the prevalence of intensive glycaemic control in this group, potential overtreatment among older adults and the impact of overtreatment on the risk of serious events. METHODS: We conducted a retrospective, population-based cohort study of community-dwelling older adults in Ontario using administrative data. Participants were ≥75 years of age with diagnosed diabetes treated with at least one anti-hyperglycaemic agent between 2014 and 2015. Individuals were categorised as having intensive or conservative glycaemic control (HbA1c <53 mmol/mol [<7%] or 54-69 mmol/mol [7.1-8.5%], respectively), and as undergoing treatment with high-risk (i.e. insulin, sulfonylureas) or low-risk (other) agents. We measured the composite risk of emergency department visits, hospitalisations, or death within 30 days of reaching intensive glycaemic control with high-risk agents. RESULTS: Among 108,620 older adults with diagnosed diabetes in Ontario, the mean (± SD) age was 80.6 (±4.5) years, 49.7% were female, and mean (± SD) diabetes duration was 13.7 (±6.3) years. Overall, 61% of individuals were treated to intensive glycaemic control and 21.6% were treated to intensive control using high-risk agents. Using inverse probability treatment weighting with propensity scores, intensive control with high-risk agents was associated with nearly 50% increased risk of the composite outcome compared with conservative glycaemic control with low-risk agents (RR 1.49, 95% CI 1.08, 2.05). CONCLUSIONS/INTERPRETATION: Our findings underscore the need to re-evaluate glycaemic targets in older adults and to reconsider the use of anti-hyperglycaemic medications that may lead to hypoglycaemia, especially in setting of intensive glycaemic control.

Influenza Vaccine Effectiveness Against All-Cause Mortality Following Laboratory-Confirmed Influenza in Older Adults, 2010-2011 to 2015-2016 Seasons in Ontario, Canada.

BACKGROUND: Older adults are at increased risk of mortality from influenza infections. We estimated influenza vaccine effectiveness (VE) against mortality following laboratory-confirmed influenza. METHODS: Using a test-negative design study and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against all-cause mortality following laboratory-confirmed influenza for community-dwelling adults aged >65 years during the 2010-2011 to 2015-2016 influenza seasons. RESULTS: Among 54 116 older adults tested for influenza across the 6 seasons, 6837 died within 30 days of specimen collection. Thirteen percent (925 individuals) tested positive for influenza, and 50.6% were considered vaccinated for that season. Only 23.2% of influenza test-positive cases had influenza recorded as their underlying cause of death. Before and after multivariable adjustment, we estimated VE against all-cause mortality following laboratory-confirmed influenza to be 20% (95% confidence interval [CI], 8%-30%) and 20% (95% CI, 7%-30%), respectively. This estimate increased to 34% after correcting for influenza vaccination exposure misclassification. We observed significant VE against deaths following influenza confirmation during 2014-2015 (VE = 26% [95% CI, 5%-42%]). We also observed significant VE against deaths following confirmation of influenza A/H1N1 and A/H3N2, and against deaths with COPD as the underlying cause. CONCLUSIONS: These results support the importance of influenza vaccination in older adults, who account for most influenza-associated deaths annually.

Population-Wide Peer Comparison Audit and Feedback to Reduce Antibiotic Initiation and Duration in Long-Term Care Facilities with Embedded Randomized Controlled Trial.

BACKGROUND: Antibiotic overprescribing in long-term care settings is driven by prescriber preferences and is associated with preventable harms for residents. We aimed to determine whether peer comparison audit and feedback reporting for physicians reduces antibiotic overprescribing among residents. METHODS: We employed a province wide, difference-in-differences study of antibiotic prescribing audit and feedback, with an embedded pragmatic randomized controlled trial (RCT) across all long-term care facilities in Ontario, Canada, in 2019. The study year included 1238 physicians caring for 96 185 residents. In total, 895 (72%) physicians received no feedback; 343 (28%) were enrolled to receive audit and feedback and randomized 1:1 to static or dynamic reports. The primary outcomes were proportion of residents initiated on an antibiotic and proportion of antibiotics prolonged beyond 7 days per quarter. RESULTS: Among all residents, between the first quarter of 2018 and last quarter of 2019, there were temporal declines in antibiotic initiation (28.4% to 21.3%) and prolonged duration (34.4% to 29.0%). Difference-in-differences analysis confirmed that feedback was associated with a greater decline in prolonged antibiotics (adjusted difference -2.65%, 95% confidence interval [CI]: -4.93 to -.28%, P = .026), but there was no significant difference in antibiotic initiation. The reduction in antibiotic durations was associated with 335 912 fewer days of treatment. The embedded RCT detected no differences in outcomes between the dynamic and static reports. CONCLUSIONS: Peer comparison audit and feedback is a pragmatic intervention that can generate small relative reductions in the use of antibiotics for prolonged durations that translate to large reductions in antibiotic days of treatment across populations. Clinical Trials Registration. NCT03807466.

Acute Myocardial Infarction after Laboratory-Confirmed Influenza Infection.

BACKGROUND: Acute myocardial infarction can be triggered by acute respiratory infections. Previous studies have suggested an association between influenza and acute myocardial infarction, but those studies used nonspecific measures of influenza infection or study designs that were susceptible to bias. We evaluated the association between laboratory-confirmed influenza infection and acute myocardial infarction. METHODS: We used the self-controlled case-series design to evaluate the association between laboratory-confirmed influenza infection and hospitalization for acute myocardial infarction. We used various high-specificity laboratory methods to confirm influenza infection in respiratory specimens, and we ascertained hospitalization for acute myocardial infarction from administrative data. We defined the "risk interval" as the first 7 days after respiratory specimen collection and the "control interval" as 1 year before and 1 year after the risk interval. RESULTS: We identified 364 hospitalizations for acute myocardial infarction that occurred within 1 year before and 1 year after a positive test result for influenza. Of these, 20 (20.0 admissions per week) occurred during the risk interval and 344 (3.3 admissions per week) occurred during the control interval. The incidence ratio of an admission for acute myocardial infarction during the risk interval as compared with the control interval was 6.05 (95% confidence interval [CI], 3.86 to 9.50). No increased incidence was observed after day 7. Incidence ratios for acute myocardial infarction within 7 days after detection of influenza B, influenza A, respiratory syncytial virus, and other viruses were 10.11 (95% CI, 4.37 to 23.38), 5.17 (95% CI, 3.02 to 8.84), 3.51 (95% CI, 1.11 to 11.12), and 2.77 (95% CI, 1.23 to 6.24), respectively. CONCLUSIONS: We found a significant association between respiratory infections, especially influenza, and acute myocardial infarction. (Funded by the Canadian Institutes of Health Research and others.).

Health services utilization prior to amyotrophic lateral sclerosis diagnosis: A province-wide study of individuals treated with riluzole in Ontario, Canada.

INTRODUCTION/AIMS: Amyotrophic lateral sclerosis (ALS) symptoms mimic those of other conditions and often require multiple physician and healthcare contacts for investigation and accurate diagnosis. We examined the type and frequency of healthcare service utilization prior to ALS diagnosis and tracheostomy-free survival by sex and rurality among individuals treated with riluzole in Ontario, Canada. METHODS: This population-based cohort study used administrative databases to identify patients aged 18+ y diagnosed with ALS and started on riluzole between April 2002-March 2018. Using Poisson regression, rate ratios of healthcare utilization and atypical diagnostic tests and unnecessary therapeutic interventions 5 y prior to ALS diagnosis were compared by sex and rurality. Tracheostomy-free survival after diagnosis was compared between groups using Kaplan-Meier estimators and proportional hazards models. RESULTS: A total of 1071 patients with ALS were identified with a mean age of 70 y; 563 (52.6%) were men and 134 (12.5%) were rural residents. The number of physician visits increased in the 18 mo prior to ALS diagnosis. We observed modest sex differences in healthcare utilization. Rural patients had lower neurologist visit rates (rate ratio [RR], 0.78; 95% confidence interval [CI], 0.70-0.87) and were significantly more likely to receive an atypical diagnostic test or unnecessary therapeutic intervention (RR, 1.80; 95% CI, 1.04-3.10). Tracheostomy-free survival did not differ by sex (log-rank P-value = .78) or rurality (log-rank P-value = .84). DISCUSSION: Given disparities observed in healthcare of rural ALS patients, policy strategies are needed to ensure all patients have timely access to care along the pathway from symptom onset to ALS diagnosis, to enable access to new therapeutics and clinical trials.

Preterm birth and stillbirth rates during the COVID-19 pandemic: a population-based cohort study.

BACKGROUND: Conflicting reports have emerged for rates of preterm births and stillbirths during the COVID-19 pandemic. Most of these reports did not account for natural variation in these rates. We aimed to evaluate variations in preterm birth and stillbirth rates before and during the COVID-19 pandemic in Ontario, Canada. METHODS: We conducted a retrospective cohort study using linked population health administrative databases of pregnant people giving birth in any hospital in Ontario between July 2002 and December 2020. We calculated preterm birth and stillbirth rates. We assessed preterm birth at 22-28, 29-32 and 33-36 weeks' gestation, and stillbirths at term and preterm gestation. We used Laney control P' charts for the 18-year study period (6-mo observation periods) and interrupted time-series analyses for monthly rates for the most recent 4 years. RESULTS: We evaluated 2 465 387 pregnancies, including 13 781 that resulted in stillbirth. The mean preterm birth rate for our cohort was 7.96% (range 7.32%-8.59%). From January to December 2020, we determined that the preterm birth rate in Ontario was 7.87%, with no special cause variation. The mean stillbirth rate for the cohort was 0.56% (range 0.48%-0.70%). From January to December 2020, the stillbirth rate was 0.53%, with no special cause variation. We did not find any special cause variation for preterm birth or stillbirth subgroups. We found no changes in slope or gap between prepandemic and pandemic periods using interrupted time-series analyses. INTERPRETATION: In Ontario, Canada, we found no special cause variation (unusual change) in preterm birth or stillbirth rates, overall or by subgroups, during the first 12 months of the COVID-19 pandemic compared with the previous 17.5 years.

Impact of Dementia on Patterns of Home Care After Inpatient Rehabilitation Discharge for Older Adults After Hip Fractures.

OBJECTIVE: To describe differences in home care use in the 30 days after discharge from inpatient rehabilitation after a hip fracture among older adults with dementia compared with those without dementia. DESIGN: Retrospective cohort study of individually linked health administrative data. SETTING: Community-dwelling older adults after discharge from inpatient rehabilitation facilities in Ontario, Canada. PARTICIPANTS: A total of 17,263 older adults (N=17,263), of whom 2489 had dementia (14.4%), who were treated for hip fracture in acute care and then admitted to inpatient rehabilitation facilities between January 1, 2011 and March 31, 2017. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The proportion receiving home care services and number of visits (physiotherapy, occupational therapy, nursing, personal/homemaking) in the 30 days after discharge were compared by dementia status with multivariate models, stratified by sex. RESULTS: Compared with those without dementia, adults with dementia were older, had lower functional scores, and were more likely to receive home care services in the 30 days after discharge from inpatient rehabilitation (87.0% vs 79.0%, P<.001), including personal/homemaking services (66.1% vs 46.4%, P<.001) and occupational therapy (45.3% vs 37.4, P<.001) but not physiotherapy (55.8% vs 56.2%, P=.677) or nursing (19.6% vs 18.7%, P=.268). After adjustment, older adults with dementia were more likely to receive home care in both men (odds ratio [OR] =2.01; 95% confidence interval [CI], 1.57-2.57) and women (OR=1.50; 95% CI, 1.30-1.74) as well as more services (rate ratio men=1.60; 95% CI, 1.44-1.79; rate ratio women=1.50; 95% CI, 1.41-1.60). CONCLUSIONS: Among older adults discharged from inpatient rehabilitation, older adults with dementia received home care services more often than older adults without dementia. However, irrespective of sex and dementia status, almost half of this population (44%) did not receive physiotherapy. We recommend that, resources permitting, all older adults receive physiotherapy to facilitate recovery.

Influenza Vaccine Effectiveness in Preventing Hospitalizations in Older Patients With Chronic Obstructive Pulmonary Disease.

BACKGROUND: Annual influenza immunization is recommended for people with chronic obstructive pulmonary disease (COPD) by all major COPD clinical practice guidelines. We sought to determine the seasonal influenza vaccine effectiveness (VE) against laboratory-confirmed influenza-associated hospitalizations among older adults with COPD. METHODS: We conducted a test-negative study of influenza VE in community-dwelling older adults with COPD in Ontario, Canada using health administrative data and respiratory specimens collected from patients tested for influenza during the 2010-11 to 2015-16 influenza seasons. Influenza vaccination was ascertained from physician and pharmacist billing claims. Multivariable logistic regression was used to estimate the adjusted odds ratio of influenza vaccination in people with, compared to those without, laboratory-confirmed influenza. RESULTS: Receipt of seasonal influenza vaccine was associated with an adjusted 22% (95% confidence interval [CI], 15%-27%) reduction in laboratory-confirmed influenza-associated hospitalization. Adjustment for potential misclassification of vaccination status increased this to 43% (95% CI, 35%-52%). Vaccine effectiveness was not found to vary by patient- or influenza-related variables. CONCLUSIONS: During the studied influenza seasons, influenza vaccination was at least modestly effective in reducing laboratory-confirmed influenza-associated hospitalizations in people with COPD. The imperfect effectiveness emphasizes the need for better influenza vaccines and other preventive strategies.

Resident-Level Predictors of Dementia Pharmacotherapy at Long-Term Care Admission: The Impact of Different Drug Reimbursement Policies in Ontario and Saskatchewan: Prédicteurs de la pharmacothérapie de la démence au niveau des résidents lors de l'hospitalisation dans des soins de longue durée : l'impact de différentes politiques de remboursement des médicaments en Ontario et en Saskatchewan.

OBJECTIVES: Cholinesterase inhibitors (ChEIs) and memantine are approved for Alzheimer disease in Canada. Regional drug reimbursement policies are associated with cross-provincial variation in ChEI use, but it is unclear how these policies influence predictors of use. Using standardized data from two provinces with differing policies, we compared resident-level characteristics associated with dementia pharmacotherapy at long-term care (LTC) admission. METHODS: Using linked clinical and administrative databases, we examined characteristics associated with dementia pharmacotherapy use among residents with dementia and/or significant cognitive impairment admitted to LTC facilities in Saskatchewan (more restrictive reimbursement policies; n = 10,599) and Ontario (less restrictive; n = 93,331) between April 1, 2009, and March 31, 2015. Multivariable logistic regression models were utilized to assess resident demographic, functional, and clinical characteristics associated with dementia pharmacotherapy. RESULTS: On admission, 8.1% of Saskatchewan residents were receiving dementia pharmacotherapy compared to 33.2% in Ontario. In both provinces, residents with severe cognitive impairment, aggressive behaviors, and recent antipsychotic use were more likely to receive dementia pharmacotherapy; while those who were unmarried, admitted in later years, had a greater degree of frailty, and recent hospitalizations were less likely. The direction of the association for older age, rural residency, medication number, and anticholinergic therapy differed between provinces. CONCLUSIONS: While more restrictive criteria for dementia pharmacotherapy coverage in Saskatchewan resulted in fewer residents entering LTC on dementia pharmacotherapy, there were relatively few differences in the factors associated with use across provinces. Longitudinal studies are needed to assess how differences in prevalence and characteristics associated with use impact patient outcomes.

The impact of repeated vaccination using 10-year vaccination history on protection against influenza in older adults: a test-negative design study across the 2010/11 to 2015/16 influenza seasons in Ontario, Canada.

IntroductionAnnual influenza vaccination is recommended for older adults, but evidence regarding the impact of repeated vaccination has been inconclusive.AimWe investigated vaccine effectiveness (VE) against laboratory-confirmed influenza and the impact of repeated vaccination over 10 previous seasons on current season VE among older adults.MethodsWe conducted an observational test-negative study in community-dwelling adults aged > 65 years in Ontario, Canada for the 2010/11 to 2015/16 seasons by linking laboratory and health administrative data. We estimated VE using multivariable logistic regression. We assessed the impact of repeated vaccination by stratifying by previous vaccination history.ResultsWe included 58,304 testing episodes for respiratory viruses, with 11,496 (20%) testing positive for influenza and 31,004 (53%) vaccinated. Adjusted VE against laboratory-confirmed influenza for the six seasons combined was 21% (95% confidence interval (CI): 18 to 24%). Patients who were vaccinated in the current season, but had received no vaccinations in the previous 10 seasons, had higher current season VE (34%; 95%CI: 9 to 52%) than patients who had received 1-3 (26%; 95%CI: 13 to 37%), 4-6 (24%; 95%CI: 15 to 33%), 7-8 (13%; 95%CI: 2 to 22%), or 9-10 (7%; 95%CI: -4 to 16%) vaccinations (trend test p = 0.001). All estimates were higher after correcting for misclassification of current season vaccination status. For patients who were not vaccinated in the current season, residual protection rose significantly with increasing numbers of vaccinations received previously.ConclusionsAlthough VE appeared to decrease with increasing numbers of previous vaccinations, current season vaccination likely provides some protection against influenza regardless of the number of vaccinations received over the previous 10 influenza seasons.

Prescribing Patterns for Treatment of Mycobacterium avium Complex and M. xenopi Pulmonary Disease in Ontario, Canada, 2001-2013.

Surveys suggest that clinicians diverge from guidelines when treating Mycobacterium avium complex (MAC) pulmonary disease (PD). To determine prescribing patterns, we conducted a cohort study of adults >66 years of age in Ontario, Canada, with MAC or Mycobacterium xenopi PD during 2001-2013. Using linked laboratory and health administrative databases, we studied the first treatment episode (>60 continuous days of >1 of a macrolide, ethambutol, rifamycin, fluoroquinolone, linezolid, inhaled amikacin, or, for M. xenopi, isoniazid). Treatment was prescribed for 24% MAC and 15% of M. xenopi PD patients. Most commonly prescribed was the recommended combination of macrolide, ethambutol, and rifamycin, for 47% of MAC and 36% of M. xenopi PD patients. Among MAC PD patients, 20% received macrolide monotherapy and 33% received regimens associated with emergent macrolide resistance. Although the most commonly prescribed regimen was guidelines-recommended, many regimens prescribed for MAC PD were associated with emergent macrolide resistance.

The Incremental Health Care Costs of Frailty Among Home Care Recipients With and Without Dementia in Ontario, Canada: A Cohort Study.

OBJECTIVE: In this study, we investigated the incremental 1-year direct costs of health care associated with frailty among home care recipients in Ontario with and without dementia. METHODS: We conducted a cohort study of 159,570 home care clients aged 50 years and older in Ontario, Canada in 2014/2015. At index home care assessment, we ascertained dementia status using a validated algorithm and frailty level (robust, prefrail, frail) based on the proportion of accumulated to potential health deficits. Clients were followed for 1-year during which we obtained direct overall and sector-specific publicly-funded health care costs (in 2015 Canadian dollars). We estimated the incremental effect of frailty level on costs using a 3-part survival- and covariate-adjusted estimator. All analyses were stratified by dementia status. RESULTS: Among those with dementia (n=42,828), frailty prevalence was 32.1% and the average 1-year cost was $30,472. The incremental cost of frailty (vs. robust) was $10,845 [95% confidence interval (CI): $10,112-$11,698]. Among those without dementia (n=116,742), frailty prevalence was 25.6% and the average 1-year cost was $28,969. Here, the incremental cost of frailty (vs. robust) was $12,360 (95% CI: $11,849-$12,981). Large differences in survival between frailty levels reduced incremental cost estimates, particularly for the dementia group (survival effect: -$2742; 95% CI: -$2914 to -$2554). CONCLUSIONS: Frailty was associated with greater 1-year health care costs for persons with and without dementia. This difference was driven by a greater intensity of health care utilization among frail clients. Mortality differences across the frailty levels mitigated the association especially among those with dementia.

Association between Physician Intensity of Antibiotic Prescribing and the Prescription of Benzodiazepines, Opioids and Proton-Pump Inhibitors to Nursing Home Residents: a Population-Based Observational Study.

BACKGROUND: Prescribing patterns for episodic medications, such as antibiotics, might make useful surrogate measures of a physician's overall prescribing practice because use is common, and variation exists across prescribers. However, the extent to which a physician's current antibiotic prescribing practices are associated with the rate of prescription of other potentially harmful medications remains unknown. OBJECTIVE: To examine the association between a physician's rate of antibiotic prescribing and their prescribing rate of benzodiazepines, opioids and proton-pump inhibitors in older adults. DESIGN: Population-based cohort study in nursing homes in Ontario, Canada, which provides comprehensive clinical, behavioural and functional information on all patients. PARTICIPANTS: 1926 physicians who provided care among 128,979 physician-patient pairs in 2015. MAIN MEASURES: Likelihood of prescribing a benzodiazepine, opioid or proton-pump inhibitor between low-, average- and high-intensity antibiotic prescribers, adjusted for patient characteristics. KEY RESULTS: Compared with average-intensity antibiotic prescribers, high-intensity prescribers had an increased likelihood of prescribing a benzodiazepine (odds ratio 1.21 [95% CI, 1.11-1.32]), an opioid (odds ratio 1.28 [95% CI, 1.17-1.39]) or a proton-pump inhibitor (odds ratio 1.38 [95% CI, 1.27-1.51]]. High-intensity antibiotic prescribers were more likely to be high prescribers of all three medications (odds ratio 6.24 [95% CI, 2.90-13.39]) and also more likely to initiate all three medications, compared with average-intensity prescribers. CONCLUSIONS: The intensity of a physician's episodic antibiotic prescribing was significantly associated with the likelihood of new and continued prescribing of opioids, benzodiazepines and proton-pump inhibitors in nursing homes. Patterns of episodic prescribing may be a useful mechanism to target physician-level interventions to optimize general prescribing behaviors, instead of prescribing behaviors for single medications.

Sodium glucose cotransporter 2 inhibitors and risk of genital mycotic and urinary tract infection: A population-based study of older women and men with diabetes.

AIMS: The objective of the study was to quantify the association between SGLT2 inhibitors and genital mycotic infection and between SGLT2 inhibitors and urinary tract infection (UTI) within 30 days of drug initiation among older women and men. MATERIALS AND METHODS: This was a retrospective cohort study using linked administrative databases of women and men with diabetes, aged 66 years or older, in Ontario, Canada. We compared the incidence of genital mycotic infection or UTI within 30 days between new users of an SGLT2 inhibitor and of a dipeptidyl-peptidase-4 (DPP4) inhibitor. RESULTS: We identified 21 444 incident users of SGLT2 inhibitor and 22 463 incident users of DPP4 inhibitor. Among SGLT2 inhibitor users, there were 8848 (41%) women and the mean age at index was 71.8 ± 5 (SD) years. After adjusting for propensity score, age, sex and recent UTI, there was a 2.47-fold increased risk of genital mycotic infection with incident use of SGLT2 inhibitors (adjusted hazard ratio (HR), 2.47; 95% confidence interval (CI), 2.08-2.92; P < 0.001) within 30 days compared to incident use of DPP4 inhibitors. For UTI, the adjusted HR was 0.89 (95% CI, 0.78-1.00; P = 0.05). CONCLUSIONS: Incident use of SGLT2 inhibitors among older women and men is associated with increased risk of genital mycotic infections within 30 days; there is no associated increased risk of UTI. These findings from a real-world setting provide evidence of the potential harms of SGLT2 inhibitors.

One-year survival and admission to hospital for cardiovascular events among older residents of long-term care facilities who were prescribed intensive- and moderate-dose statins.

BACKGROUND: Guidance from randomized clinical trials about the ongoing benefits of statin therapies in residents of long-term care facilities is lacking. We sought to examine the effect of statin dose on 1-year survival and admission to hospital for cardiovascular events in this setting. METHODS: We conducted a retrospective cohort study using population-based administrative data from Ontario, Canada. We identified 21 808 residents in long-term care facilities who were 76 years of age and older and were prevalent statin users on the date of a full clinical assessment between April 2013 and March 2014, and categorized residents as intensive- or moderate-dose users. Treatment groups were matched on age, sex, admission to hospital for atherosclerotic cardiovascular disease, resident frailty and propensity score. Differences in 1-year survival and admission to hospital for cardiovascular events were measured using Cox proportional and subdistribution hazard models, respectively. RESULTS: Using propensity-score matching, we included 4577 well-balanced pairs of residents who were taking intensive- and moderate-dose statins. After 1 year, there were 1210 (26.4%) deaths and 524 (11.5%) admissions to hospital for cardiovascular events among residents using moderate-dose statins compared with 1173 (25.6%) deaths and 522 (11.4%) admissions to hospital for cardiovascular events among those taking intensive-dose statins. We found no significant association between prevalent use of intensive-dose statins and 1-year survival (hazard ratio [HR] 0.97, 95% confidence interval [CI] 0.90 to 1.05) or 1-year admission to hospital for cardiovascular events (HR 0.99, 95% CI 0.88 to 1.12) compared with use of moderate-dose statins. INTERPRETATION: The rates of mortality and admission to hospital for cardiovascular events at 1 year were similar between residents in long-term care taking intensive-dose statins compared with those taking moderate-dose statins. This lack of benefit should be considered when prescribing statins to vulnerable residents of long-term care facilities who are at potentially increased risk of statin-related adverse events.

Cardiovascular and Neuropsychiatric Events after Varenicline Use for Smoking Cessation.

RATIONALE: Varenicline aids in smoking cessation but has also been associated with serious adverse events. OBJECTIVES: The aim of this study was to determine the risks of cardiovascular and neuropsychiatric events after varenicline receipt in a real-world setting. METHODS: A population-based, self-controlled risk interval study using linked universal health administrative data from the diverse, multicultural population of Ontario, Canada, was conducted. In two separate analyses, new varenicline users between September 1, 2011 and February 15, 2014 were observed from 1 year before to 1 year after varenicline receipt. The relative incidences of cardiovascular and neuropsychiatric hospitalizations and emergency department visits in the 12 weeks after varenicline receipt (the risk interval) compared with the remaining observation period (the control interval) were estimated in two separate fixed-effect conditional Poisson regressions. Sensitivity analyses tested the robustness of the results. MEASUREMENTS AND MAIN RESULTS: Among 56,851 new users of varenicline, 6,317 cardiovascular and 10,041 neuropsychiatric hospitalizations and emergency department visits occurred from 1 year before to 1 year after receipt. The incidence of cardiovascular events was 34% higher in the risk compared with the control interval (relative incidence, 1.34; 95% confidence interval, 1.25-1.44). Findings were consistent in sensitivity analyses, most notably in those without any history of previous cardiovascular disease. The relative incidence of neuropsychiatric events was marginally significant in the primary (relative incidence, 1.06; 95% confidence interval, 1.00-1.13) but not all sensitivity analyses. CONCLUSIONS: Varenicline appears to be associated with an increased risk of cardiovascular but not neuropsychiatric events.