A population-based time-series analysis of opioid agonist treatment dispensed during pregnancy

BACKGROUND AND AIMS

Identifying effective opioid treatment options during pregnancy is a high priority due to the growing prevalence of opioid use disorder across North America. We assessed the temporal impact of three population-level interventions on the use of opioid agonist treatment (OAT) during pregnancy in Ontario, Canada.

DESIGN

This was a population-based time-series analysis to identify trends in the monthly prevalence of pregnant people dispensed methadone and buprenorphine. The impact of adding buprenorphine/naloxone to the public drug formulary, the release of pregnancy-specific guidance and the start of the COVID-19 pandemic were assessed.

SETTING AND PARTICIPANTS

The study was conducted in Ontario, Canada between 1 July 2013 and 31 March 2022, comprising people who delivered a live or stillbirth in any Ontario hospital during the study period.

MEASUREMENTS

We identified any prescription for methadone or buprenorphine dispensed between the estimated conception date and delivery date and calculated the monthly prevalence of OAT-exposed pregnancies among all pregnant people in Ontario.

FINDINGS

Overall, rates of OAT during pregnancy have declined since mid-2018. Methadone-exposed pregnancies decreased from 0.46% of all pregnancies in Ontario in 2015 to a low of 0.16% in 2022. In the primary analysis, none of the interventions had a statistically significant impact on overall OAT rates; however, in the stratified analyses, there was a small increase in buprenorphine after the formulary change [0.006%, 95% confidence interval (CI) = 0.0032-0.0081, P < 0.0001] and a decrease in buprenorphine after the release of the 2017 guidelines (-0.005%, 95% CI = -0.0080 to -0.0020, P = 0.001) and the start of the COVID-19 pandemic (-0.003%, 95% CI = -0.0054 to -0.0006, P = 0.015).

CONCLUSION

Despite changes in guidance and funding, opioid agonist treatment during pregnancy has been declining in Ontario, Canada since 2018.

Association between surgery and rate of incident dementia in older adults: A population-based retrospective cohort study

BACKGROUND

The risk of incident dementia after surgery in older adults is unclear. The study objective was to examine the rate of incident dementia among older adults after elective surgery compared with a matched nonsurgical control group.

METHODS

We conducted a population-based, propensity-matched retrospective cohort study using data from linked administrative databases in Ontario, Canada. All community-dwelling individuals aged 66 years and older who underwent one of five major elective surgeries between April 1, 2007 and March 31, 2011 were included. Each surgical patient was matched 1:1 on surgical specialty of the surgeon at consultation, age, sex, fiscal year of entry, and propensity score with a patient who attended an outpatient visit with a surgeon of the same surgical specialty but did not undergo surgery. Patients were followed for up to 5 years after cohort entry for the occurrence of a new dementia diagnosis, defined from administrative data. Cause-specific hazard models were used to estimate the hazard ratio (HR) and 95% confidence interval (CI) for the association between surgery and the hazard of incident dementia. Subgroup and sensitivity analyses were performed.

RESULTS

A total of 27,878 individuals (13,939 matched pairs) were included in the analysis. A total of 640 (4.6%) individuals in the surgical group and 965 (6.9%) individuals in the control group developed dementia over the 5-year follow-up period. Individuals who underwent surgery had a reduced rate of incident dementia compared with their matched nonsurgical controls (HR 0.88; 95% CI 0.80-0.97; p = 0.01). This association was persistent in most subgroups and after sensitivity analyses.

CONCLUSIONS

Elective surgery did not increase the rate of incident dementia when compared with matched nonsurgical controls. This could be an important consideration for patients and surgeons when elective surgery is considered.

Surgeon factors but not hospital factors associated with length of stay after colorectal surgery - A population based study

AIM

Length of stay (LOS) after colorectal surgery (CRS) is a significant driver of healthcare utilization and adverse patient outcomes. To date, there is little high-quality evidence in the literature examining how individual surgeon and hospital factors independently impact LOS. We aimed to identify and quantify the independent impact of surgeon and hospital factors on LOS after CRS.

METHODS

A retrospective population-based cohort study was conducted using validated health administrative databases, encompassing all patients from the province of Ontario, Canada. All patients from 121 hospitals in Ontario who underwent elective CRS between 2008 and 2019 in Ontario were included, and factors pertaining to these patients and their treating surgeon and hospital were assessed. A negative binomial regression model was used to assess the independent effect of surgeon and hospital factors on LOS, accounting for a comprehensive collection of determinants of LOS. To minimize unmeasured confounding, the analysis was repeated in a subgroup comprising patients undergoing lower-complexity CRS without postoperative complications.

RESULTS

A total of 90,517 CRS patients were analysed. Independent of patient and procedural factors, low surgeon volume (lowest volume quartile) was associated with a 20% increase in LOS (95% CI: 12-29, p < 0.0001) compared to high surgeon volume (highest volume quartile). In the 22,639 patients undergoing uncomplicated lower-complexity surgeries, a 43% longer LOS was seen in the lowest volume surgeon quartile (95% CI: 26-61, p < 0.0001). In both models, more years-in-practice was associated with a small increase in LOS (RR 1.02, 95% CI: 1.02-1.03, p < 0.0001). Hospital factors were not significantly associated with increased LOS.

CONCLUSIONS

Surgeon factors, including low surgeon volume and increasing years-in-practice, were strongly and independently associated with longer LOS, whereas hospital factors did not have an independent impact. This suggests that LOS is driven primarily by surgeon-mediated care processes and may provide actionable targets for provider-level interventions to reduce LOS after CRS.

COVID-19 vaccine equity: a retrospective population-based cohort study examining primary series and first booster coverage among persons with a history of immigration and other residents of Ontario, Canada

Introduction

Immigrants were disproportionately impacted by COVID-19 and experience unique vaccination barriers. In Canada (37 million people), 23% of the population is foreign-born. Immigrants constitute 60% of the country's racialized (non-white) population and over half of immigrants reside in Ontario, the country's most populous province. Ontario had several strategies aimed at improving vaccine equity including geographic targeting of vaccine supply and clinics, as well as numerous community-led efforts. Our objectives were to (1) compare primary series vaccine coverage after it was widely available, and first booster coverage 6 months after its availability, between immigrants and other Ontario residents and (2) identify subgroups experiencing low coverage.

Materials and methods

Using linked immigration and health administrative data, we conducted a retrospective population-based cohort study including all community-dwelling adults in Ontario, Canada as of January 1, 2021. We compared primary series (two-dose) vaccine coverage by September 2021, and first booster (three-dose) coverage by March 2022 among immigrants and other Ontarians, and across sociodemographic and immigration characteristics. We used multivariable log-binomial regression to estimate adjusted risk ratios (aRR).

Results

Of 11,844,221 adults, 22% were immigrants. By September 2021, 72.6% of immigrants received two doses (vs. 76.4%, other Ontarians) and by March 2022 46.1% received three doses (vs. 58.2%). Across characteristics, two-dose coverage was similar or slightly lower, while three-dose coverage was much lower, among immigrants compared to other Ontarians. Across neighborhood SARS-CoV-2 risk deciles, differences in two-dose coverage were smaller in higher risk deciles and larger in the lower risk deciles; with larger differences across all deciles for three-dose coverage. Compared to other Ontarians, immigrants from Central Africa had the lowest two-dose (aRR = 0.60 [95% CI 0.58-0.61]) and three-dose coverage (aRR = 0.36 [95% CI 0.34-0.37]) followed by Eastern Europeans and Caribbeans, while Southeast Asians were more likely to receive both doses. Compared to economic immigrants, resettled refugees and successful asylum-claimants had the lowest three-dose coverage (aRR = 0.68 [95% CI 0.68-0.68] and aRR = 0.78 [95% CI 0.77-0.78], respectively).

Conclusion

Two dose coverage was more equitable than 3. Differences by immigrant region of birth were substantial. Community-engaged approaches should be re-invigorated to close gaps and promote the bivalent booster.

Trends and correlates of concurrent opioid and benzodiazepine and/or gabapentinoid use among Ontario nursing home residents

BACKGROUND

A concern with long-term opioid use is the increased risk arising when opioids are used concurrently with drugs that can potentiate their associated adverse effects. The drugs most often encountered are benzodiazepines (BZDs) and gabapentinoids. Our study objectives were to examine trends in the concurrent use of opioids and BZDs, or gabapentinoids, in a Canadian nursing home population over an 11-year period, and current resident-level correlates of this concurrent use.

METHODS

We conducted a population-based, repeated cross-sectional study among Ontario nursing home residents (>65 years) dispensed opioids between April 2009 and February 2020. For the last study year, we examined cross-sectional associations between resident characteristics and concurrent use of opioids with BZDs or gabapentinoids. Linked data on nursing home residents from clinical and health administrative databases was used. The yearly proportions of residents who were dispensed an opioid concurrently with a BZD or gabapentinoid were plotted with percent change derived from log-binomial regression models. Separate modified Poisson regression models estimated resident-level correlates of concurrent use of opioids with BZDs or gabapentinoids.

RESULTS

Over the study period, among residents dispensed an opioid there was a 53.2% relative decrease (30.7% to 14.4%) in concurrent BZD and a 505.4% relative increase (4.4% to 26.6%) in concurrent gabapentinoid use. In adjusted models, increasing age and worsening cognition were inversely associated with the concurrent use of both classes, but most other significantly related covariates were unique to each drug class (e.g., sex and anxiety disorders for BZD, pain severity and presence of pain-related conditions for gabapentinoids).

CONCLUSIONS

Co-administration of BZDs or gabapentinoids in Ontario nursing home residents dispensed opioids remains common, but the pattern of co-use has changed over time. Observed covariates of concurrent use in 2019/20 suggest distinct but overlapping resident populations requiring consideration of the relative risks versus benefits of this co-use and monitoring for potential harm.

A population-based study of factors associated with systemic treatment in advanced prostate cancer decedents

INTRODUCTION

Life-prolonging therapies (LPTs) are rapidly evolving for the treatment of advanced prostate cancer, although factors associated with real-world uptake are not well characterized.

METHODS

In this cohort of prostate-cancer decedents, we analyzed factors associated with LPT access. Population-level databases from Ontario, Canada identified patients 65 years or older with prostate cancer receiving androgen deprivation therapy and who died of prostate cancer between 2013 and 2017. Univariate and multivariable analyses assessed the association between baseline characteristics and receipt of LPT in the 2 years prior to death.

RESULTS

Of 3575 patients who died of prostate cancer, 40.4% (n = 1443) received LPT, which comprised abiraterone (66.3%), docetaxel (50.3%), enzalutamide (17.2%), radium-223 (10.0%), and/or cabazitaxel (3.5%). Use of LPT increased by year of death (2013: 22.7%, 2014: 31.8%, 2015: 41.8%, 2016: 49.1%, and 2017: 57.9%, p < 0.0001), driven by uptake of all agents except docetaxel. Adjusted odds of use were higher for patients seen at Regional Cancer Centers (OR: 1.8, 95% CI: 1.5-2.1) and who received prior prostate-directed therapy (OR: 1.3, 95% CI: 1.0-1.5), but lower with advanced age (≥85: OR: 0.54, 95% CI:0.39-0.75), increased chronic conditions (≥6: OR: 0.62, 95% CI: 0.43-0.92), and long-term care residency (OR: 0.38, 95% CI: 0.17-0.89). Income, stage at presentation, and distance to the cancer center were not associated with LPT uptake.

CONCLUSION

In this cohort of prostate cancer-decedents, real-world uptake of novel prostate cancer therapies occurred at substantially higher rates for patients receiving care at Regional Cancer Centers, reinforcing the potential benefits for treatment access for patients referred to specialist centers.

Analysis of the relationship between surgeon procedure volume and complications after total knee arthroplasty using a propensity-matched cohort study

Objectives

This study aimed to identify a threshold in annual surgeon volume associated with increased risk of revision (for any cause) and deep infection requiring surgery following primary elective total knee arthroplasty (TKA).

Design

A propensity score matched cohort study.

Setting

Ontario, Canada.

Participants

169 713 persons who received a primary TKA between 2002 and 2016, with 3-year postoperative follow-up.

Main outcome measures

Revision arthroplasty (for any cause), and the occurrence of deep surgical infection requiring surgery.

Results

Based on restricted cubic spline analysis, the threshold for increased probability of revision and deep infection requiring surgery was <70 cases/year. After matching of 51 658 TKA recipients from surgeons performing <70 cases/year to TKA recipients from surgeons with greater than 70 cases/year, patients in the former group had a higher rate of revision (for any cause, 2.23% (95% Confidence Interval (CI) 1.39 to 3.07) vs 1.70% (95% CI 0.85 to 2.55); Hazard Ratio (HR) 1.33, 95% CI 1.21 to 1.47, p<0.0001) and deep infection requiring surgery (1.29% (95% CI 0.44 to 2.14) vs 1.09% (95% CI 0.24 to 1.94); HR 1.33, 95% CI 1.17 to 1.51, p<0.0001).

Conclusions

For primary TKA recipients, cases performed by surgeons who had performed fewer than 70 TKAs in the year prior to the index TKA were at 31% increased relative risk of revision (for any cause), and 18% increased relative risk for deep surgical infection requiring surgery, at 3-year follow-up.

Trajectories of health system use and survival for community-dwelling persons with dementia: a cohort study

OBJECTIVES

To determine the long-term trajectories of health system use by persons with dementia as they remain in the community over time.

DESIGN

Population-based cohort study using health administrative data.

SETTING

Ontario, Canada from 1 April 2007 to 31 March 2014.

PARTICIPANTS

62 622 community-dwelling adults aged 65+ years with prevalent dementia on 1 April 2007 matched 1:1 to persons without dementia based on age, sex and comorbidity.

MAIN OUTCOME MEASURES

Rates of health service use, long-term care placement and mortality over time.

RESULTS

After 7 years, 49.0% of persons with dementia had spent time in long-term care (6.8% without) and 64.5% had died (30.0% without). Persons with dementia were more likely than those without to use home care (rate ratio (RR) 3.02, 95% CI 2.93 to 3.11) and experience hospitalisations with a discharge delay (RR 2.36, 95% CI 2.30 to 2.42). As they remained in the community, persons with dementia used home care at a growing rate (10.7%, 95% CI 10.0 to 11.3 increase per year vs 6.7%, 95% CI 4.3 to 9.0 per year among those without), but rates of acute care hospitalisation remained constant (0.6%, 95% CI -0.6 to 1.9 increase per year).

CONCLUSIONS

While persons with dementia used more health services than those without dementia over time, the rate of change in use differed by service type. These results, particularly enumerating the increased intensity of home care service use, add value to capacity planning initiatives where limited budgets require balancing services.

Smoking, drinking, diet and physical activity-modifiable lifestyle risk factors and their associations with age to first chronic disease

BACKGROUND

This study examined the incidence of a person's first diagnosis of a selected chronic disease, and the relationships between modifiable lifestyle risk factors and age to first of six chronic diseases.

METHODS

Ontario respondents from 2001 to 2010 of the Canadian Community Health Survey were followed up with administrative data until 2014 for congestive heart failure, chronic obstructive respiratory disease, diabetes, lung cancer, myocardial infarction and stroke. By sex, the cumulative incidence function of age to first chronic disease was calculated for the six chronic diseases individually and compositely. The associations between modifiable lifestyle risk factors (alcohol, body mass index, smoking, diet, physical inactivity) and age to first chronic disease were estimated using cause-specific Cox proportional hazards models and Fine-Gray competing risk models.

RESULTS

Diabetes was the most common disease. By age 70.5 years (2015 world life expectancy), 50.9% of females and 58.1% of males had at least one disease and few had a death free of the selected diseases (3.4% females; 5.4% males). Of the lifestyle factors, heavy smoking had the strongest association with the risk of experiencing at least one chronic disease (cause-specific hazard ratio = 3.86; 95% confidence interval = 3.46, 4.31). The lifestyle factors were modelled for each disease separately, and the associations varied by chronic disease and sex.

CONCLUSIONS

We found that most individuals will have at least one of the six chronic diseases before dying. This study provides a novel approach using competing risk methods to examine the incidence of chronic diseases relative to the life course and how their incidences are associated with lifestyle behaviours.

A challenge to all. A primer on inter-country differences of high-need, high-cost patients

BACKGROUND

Across countries, a small group of patients accounts for the majority of health care spending. These patients are more likely than other patients to experience problems with quality and safety in their care, suggesting that efforts targeting efficiency and quality among this population might have significant payoffs for health systems. Better understanding of similarities and differences in patient characteristics and health care use in different countries may ultimately inform further efforts to improve care for HNHC patients in these health systems.

METHODS

We conducted a cross-sectional descriptive study using one year of patient-level data on high-cost patients in seven high-income OECD member countries. Countries were selected based on availability of detailed information (large enough samples of claims, administrative, and survey data of high-cost patients). We studied concentration of spending among high-cost patients, characteristics of high-cost patients, and per capita spending on high-cost patients.

FINDINGS

Cost-concentration of the top 5% of patients varied across countries, from 41% in Japan to 60% in Canada, driven primarily by variation in the top 1% of spenders. In general, high-cost patients were more likely to be female (57.7% on average), had a significant number of multi-morbidities (up to on average 10 major diagnostic categories (ICD chapters), and had a lower socioeconomic status. Characteristics of high-cost patients varied as well: median age ranged from 62 in the Netherlands to 75 in Germany and the difference in socioeconomic status is particularly stark in the US. Lastly, utilization, particularly for inpatient care, varied with an average number of inpatient days ranging from 6.6 nights (US) to 97.7 nights in Japan.

INTERPRETATION

In this descriptive study, there is substantial variation in the cost concentration, characteristics, and per capita spending on high-cost patient populations across high-income countries. Differences in the way that health systems are structured likely explains some of this variation, which suggests the potential of cross-system learning opportunities. Our findings highlight the need for further studies including comparable performance metrics and institutional analysis.

Food insecurity status and mortality among adults in Ontario, Canada

BACKGROUND

Food insecurity is associated with a wide array of negative health outcomes and higher health care costs but there has been no population-based study of the association of food insecurity and mortality in high-income countries.

METHODS

We use cross-sectional population surveys linked to encoded health administrative data. The sample is 90,368 adults, living in Ontario and respondents in the Canadian Community Health Survey (CCHS). The outcome of interest is all-cause mortality at any time after the interview and within four years of the interview. The primary variable of interest is food insecurity status, with individuals classed as "food secure", "marginally food insecure", "moderately food insecure", or "severely food insecure". We use logistic regression models to determine the association of mortality with food insecurity status, adjusting for other social determinants of health.

RESULTS

Using a full set of covariates, in comparison to food secure individuals, the odds of death at any point after the interview are 1.28 (CI = 1.08, 1.52) for marginally food insecure individuals, 1.49 (CI = 1.29, 1.73) for moderately food insecure individuals, and 2.60 (CI = 2.17, 3.12) for severely food insecure individuals. When mortality within four years of the interview is considered, the odds are, respectively, 1.19 (CI = 0.95, 1.50), 1.65 (CI = 1.37, 1.98), and 2.31 (CI = 1.81, 2.93).

INTERPRETATION

These findings demonstrate that food insecurity is associated with higher mortality rates and these higher rates are especially large for the most severe food insecurity category. Efforts to reduce food insecurity should be incorporated into broader public health initiatives to reduce mortality.