Unplanned index hospital admissions among new older high-cost health care users in Ontario: a population-based matched cohort study

BACKGROUND

Most health care spending is concentrated within a small group of high-cost health care users. To inform health policies, we examined the characteristics of index hospital admissions and their predictors among incident older high-cost users compared to older non-high-cost users in Ontario.

METHODS

Using Ontario administrative data, we identified incident high-cost users aged 66 years or more and matched them 1:3 on age, gender and Local Health Integration Network with non-high-cost users aged 66 years or more. We defined high-cost users as patients within the top 5% most costly high-cost users during fiscal year 2013/14 but not during 2012/13. An index hospital admission, the main outcome, was defined as the first unplanned hospital admission during 2013/14, with no hospital admissions in the preceding 12 months. Descriptively, we analyzed the attributes of index hospital admissions, including costs. We identified predictors of index hospital admissions using stratified logistic regression.

RESULTS

Over half (95 375/175 847 [54.2%]) of all high-cost users had an unplanned index hospital admission, compared to 8838/527 541 (1.7%) of non-high-cost users. High-cost users had a poorer health status, longer acute length of stay (mean 7.5 d v. 2.9 d) and more frequent designation as alternate level of care before discharge (20.8% v. 1.7%) than did non-high-cost users. Ten diagnosis codes accounted for roughly one-third of the index hospital admission costs in both cohorts. Although many predictors were similar between the cohorts, a lower risk of an index hospital admission was associated with residence in long-term care, attachment to a primary care provider and recent consultation by a geriatrician among high-cost users.

INTERPRETATION

The high prevalence of index hospital admissions and the corresponding costs are a distinctive feature of incident older high-cost users. Improved access to specialist outpatient care, home-based social care and long-term care when required are worth further investigation.

Encounters with Rheumatologists in a Publicly Funded Canadian Healthcare System: A Population-based Study

OBJECTIVE

To quantify population-level and practice-level encounters with rheumatologists over time.

METHODS

We conducted a population-based study from 2000 to 2015 in Ontario, Canada, where all residents are covered by a single-payer healthcare system. Annual total number of unique patients seen by rheumatologists, the number of new patients seen, and total number of encounters with rheumatologists were identified.

RESULTS

From 2000 to 2015, the percentage of the population seen by rheumatologists was constant over time (2.7%). During this time, Ontario had a stable supply of rheumatologists (0.8 full-time equivalents/75,000). From 2000 to 2015, the number of annual rheumatology encounters increased from 561,452 to 786,061, but the adjusted encounter rates remained stable over time (at 62 encounters per 1000 population). New patient assessment rates declined over time from 10 new outpatient assessments per 1000 in 2000 to 6 per 1000 in 2015. The crude volume of new patients seen annually decreased and an increasing proportion of rheumatology encounters were with established patients. We observed a shift in patient case mix over time, with more assessments for systemic inflammatory conditions. Rheumatologists' practice volumes, practice sizes, and the annual number of days providing clinical care decreased over time.

CONCLUSION

Over a 15-year period, the annual percentage of the population seen by a rheumatologist remained constant and the volume of new patients decreased, while followup patient encounters increased. Patient encounters per rheumatologist decreased over time. Our findings provide novel information for rheumatology workforce planning. Factors affecting clinical activity warrant further research.

Trends in chronic disease incidence rates from the Canadian Chronic Disease Surveillance System

INTRODUCTION

The Public Health Agency of Canada's Canadian Chronic Disease Surveillance System (CCDSS) produces population-based estimates of chronic disease prevalence and incidence using administrative health data. Our aim was to assess trends in incidence rates over time, trends are essential to understand changes in population risk and to inform policy development.

METHODS

Incident cases of diagnosed asthma, chronic obstructive pulmonary disease (COPD), diabetes, hypertension, ischemic heart disease (IHD), and stroke were obtained from the CCDSS online infobase for 1999 to 2012. Trends in national and regional incidence estimates were tested using a negative binomial regression model with year as a linear predictor. Subsequently, models with year as a restricted cubic spline were used to test for departures from linearity using the likelihood ratio test. Age and sex were covariates in all models.

RESULTS

Based on the models with year as a linear predictor, national incidence rates were estimated to have decreased over time for all diseases, except diabetes; regional incidence rates for most diseases and regions were also estimated to have decreased. However, likelihood ratio tests revealed statistically significant departures from a linear year effect for many diseases and regions, particularly for hypertension.

CONCLUSION

Chronic disease incidence estimates based on CCDSS data are decreasing over time, but not at a constant rate. Further investigations are needed to assess if this decrease is associated with changes in health status, data quality, or physician practices. As well, population characteristics that may influence changing incidence trends also require exploration.

Quality and continuity of information between primary care physicians and rheumatologists

Background

Good communication is central to a high-quality consultation process. We assessed the quality of referral information from primary care physicians (PCPs) to rheumatologists and the quality and timeliness of consultation letters from rheumatologists back to PCPs.

Methods

We sampled referral letters between 2000 and 2013 from 168 PCPs and performed a retrospective chart review of 2430 patients referred to 146 rheumatologists. We assessed the completeness and timeliness of referral and consultation letters.

Results

Osteoarthritis (n = 787, 32%) and systemic inflammatory rheumatic diseases (n = 745, 31%) comprised the top reasons for referral. Only 55% of referral letters summarized the patients’ medical history. Referral letters provided some details of diagnostic tests (51% labs, 34% imaging) but there was underreporting of this information on referral letters. Almost all referral letters (92%) contained details of at least one patient symptom, with the most common complaint being joint pain (54%). Only half of all referral letters provided symptom duration. The PCP only stressed an urgent consultation among 211 patients (9%). Overall, 69% of consultation letters were returned to PCPs within 30 days of consultation visit.

Conclusion

We found that basic items necessary for appropriate triage, including a description of symptoms or other relevant history and results of investigations were often lacking in referral letters. The delay of receipt of consultation letters may further represent a lost opportunity for coordination and continuity of care, and may affect the quality of care patients receive.

Impact of delisting high-strength opioid formulations from a public drug benefit formulary on opioid utilization in Ontario, Canada

PURPOSE

High-strength opioid formulations were delisted (removed) from Ontario's public drug formulary in January 2017, except for palliative patients. We evaluated the impact of this policy on opioid utilization and dosing.

METHODS

We conducted a longitudinal study among patients receiving publicly funded, high-strength opioids from August 2016 to July 2017. The primary outcome measure was weekly median daily opioid dose (in milligrams of morphine or equivalent; MME) of (1) publicly funded and (2) all opioid prescriptions irrespective of funding source, evaluated using interrupted time series analyses and stratified by palliative care status.

RESULTS

Following policy implementation, the weekly median daily dose of publicly funded opioids decreased immediately among non-palliative patients by 10 MME (95% confidence limit [CL], -16.8 to -3.1) from a pre-intervention dose of 424.5 MME (95% CL, 417.8-431.2) and fell gradually among palliative patients by 3.9 MME per week (95% CL, -5.5 to -2.3) from a pre-intervention dose of 450.1 MME (95% CL, 432.5-467.7). In contrast, among all opioid prescriptions, gradual reductions in weekly median daily doses were observed only for non-palliative patients, which decreased by 0.7 MME per week (95% CL, -1.3 to -0.2) from a pre-intervention dose of 426.2 MME (95% CL, 420.9-431.5).

CONCLUSION

The delisting of publicly-funded, high-strength opioids was accompanied by changes in funding source and small reductions in the weekly median daily doses dispensed. Although observed dose reductions of less than 1 MME weekly are likely not clinically relevant, safety implications of these changes require further monitoring.

Associations Between Methotrexate Use and the Risk of Cardiovascular Events in Patients with Elderly-onset Rheumatoid Arthritis

OBJECTIVE

We evaluated the associations between time-varying methotrexate (MTX) use and risk of cardiovascular events (CVE) in patients with rheumatoid arthritis (RA).

METHODS

We studied an inception cohort of 23,994 patients with RA diagnosed after their 65th birthday. Multivariable Cox regression models were fit to evaluate the associations between time-varying MTX use, controlling for other risk factors, and time to CVE. Alternative models assessed the cumulative duration of MTX use over the (1) first year, (2) previous year (recent use), and (3) entire duration of followup. We also assessed whether the strength of the association varied over time.

RESULTS

Over 115,453 patient-years (PY), 3294 (13.7%) patients experienced a CVE (28.5 events per 1000 PY; 95% CI 27.6-29.5). In the multivariable analyses, the model assessing time-varying continuous use in the most recent year yielded the best fit. Increasing recent MTX use was associated with lower CVE risks (HR 0.79 for continuous use vs no use in past 12 months, 95% CI 0.70-0.88; p < 0.0001). Greater MTX use in the first year after cohort entry was also protective (HR 0.84, 95% CI 0.72-0.96; p = 0.0048), but this effect decreased with increasing followup. In contrast, longer MTX use during the entire followup was not clearly associated with CVE risk (HR 0.98, 95% CI 0.95-1.01; p = 0.1441).

CONCLUSION

We observed about a 20% decrease in CVE associated with recent continuous MTX use. Greater MTX use in the first year of cohort entry also appeared to be important in the association between MTX and CVE risk.

Regional variation in healthcare spending and mortality among senior high-cost healthcare users in Ontario, Canada: a retrospective matched cohort study

Background

Senior high cost health care users (HCU) are a priority for many governments. Little research has addressed regional variation of HCU incidence and outcomes, especially among incident HCU. This study describes the regional variation in healthcare costs and mortality across Ontario’s health planning districts [Local Health Integration Networks (LHIN)] among senior incident HCU and non-HCU and explores the relationship between healthcare spending and mortality.

Methods

We conducted a retrospective population-based matched cohort study of incident senior HCU defined as Ontarians aged ≥66 years in the top 5% most costly healthcare users in fiscal year (FY) 2013. We matched HCU to non-HCU (1:3) based on age, sex and LHIN. Primary outcomes were LHIN-based variation in costs (total and 12 cost components) and mortality during FY2013 as measured by variance estimates derived from multi-level models. Outcomes were risk-adjusted for age, sex, ADGs, and low-income status. In a cost-mortality analysis by LHIN, risk-adjusted random effects for total costs and mortality were graphically presented together in a cost-mortality plane to identify low and high performers.

Results

We studied 175,847 incident HCU and 527,541 matched non-HCU. On average, 94 out of 1000 seniors per LHIN were HCU (CV = 4.6%). The mean total costs for HCU in FY2013 were 12 times higher that of non-HCU ($29,779 vs. $2472 respectively), whereas all-cause mortality was 13.6 times greater (103.9 vs. 7.5 per 1000 seniors).

Regional variation in costs and mortality was lower in senior HCU compared with non-HCU. We identified greater variability in accessing the healthcare system, but, once the patient entered the system, variation in costs was low. The traditional drivers of costs and mortality that we adjusted for played little role in driving the observed variation in HCUs’ outcomes. We identified LHINs that had high mortality rates despite elevated healthcare expenditures and those that achieved lower mortality at lower costs. Some LHINs achieved low mortality at excessively high costs.

Conclusions

Risk-adjusted allocation of healthcare resources to seniors in Ontario is overall similar across health districts, more so for HCU than non-HCU. Identified important variation in the cost-mortality relationship across LHINs needs to be further explored.

Electronic supplementary material

The online version of this article (10.1186/s12877-018-0952-7) contains supplementary material, which is available to authorized users.

Prior Authorization and Canadian Public Utilization of Direct-Acting Oral Anticoagulants

Purpose:

Provincial public drug formularies in Canada have different mechanisms for reimbursement of direct-acting oral anticoagulants (DOACs). We investigate how these differences influence DOAC utilization and expenditure across the country.

Methods:

We conducted a population-based, cross-sectional study of all out-patient prescriptions for OACs dispensed to public beneficiaries between January 1, 2010, and June 30, 2015. We calculated quarterly rates of OAC use and expenditures stratified by OAC type and province.

Results:

The greatest increase in quarterly rates of DOAC utilization occurred in provinces with more liberal mechanism of drug coverage: Ontario by 462%, Alberta by 425% and Quebec by 1,924%. This translated to increased expenditure on overall OAC by 270%, 204% and 390%, respectively. In contrast, provinces with more stringent mechanisms had low rates of DOAC utilization and expenditure.

Conclusions:

DOAC utilization and expenditure is considerably different across Canada, associated with provincial difference in reimbursement mechanism.

The Canadian Chronic Disease Surveillance System: A model for collaborative surveillance

Chronic diseases have a major impact on populations and healthcare systems worldwide. Administrative health data are an ideal resource for chronic disease surveillance because they are population-based and routinely collected. For multi-jurisdictional surveillance, a distributed model is advantageous because it does not require individual-level data to be shared across jurisdictional boundaries. Our objective is to describe the process, structure, benefits, and challenges of a distributed model for chronic disease surveillance across all Canadian provinces and territories (P/Ts) using linked administrative data. The Public Health Agency of Canada (PHAC) established the Canadian Chronic Disease Surveillance System (CCDSS) in 2009 to facilitate standardized, national estimates of chronic disease prevalence, incidence, and outcomes. The CCDSS primarily relies on linked health insurance registration files, physician billing claims, and hospital discharge abstracts. Standardized case definitions and common analytic protocols are applied to the data for each P/T; aggregate data are shared with PHAC and summarized for reports and open access data initiatives. Advantages of this distributed model include: it uses the rich data resources available in all P/Ts; it supports chronic disease surveillance capacity building in all P/Ts; and changes in surveillance methodology can be easily developed by PHAC and implemented by the P/Ts. However, there are challenges: heterogeneity in administrative databases across jurisdictions and changes in data quality over time threaten the production of standardized disease estimates; a limited set of databases are common to all P/Ts, which hinders potential CCDSS expansion; and there is a need to balance comprehensive reporting with P/T disclosure requirements to protect privacy. The CCDSS distributed model for chronic disease surveillance has been successfully implemented and sustained by PHAC and its P/T partners. Many lessons have been learned about national surveillance involving jurisdictions that are heterogeneous with respect to healthcare databases, expertise and analytical capacity, population characteristics, and priorities.

Contributions of prescribed and non-prescribed opioids to opioid related deaths: population based cohort study in Ontario, Canada

OBJECTIVE

To describe the contributions of prescribed and non-prescribed opioids to opioid related deaths.

DESIGN

Population based cohort study.

SETTING

Ontario, Canada, from 1 January 2013 to 31 December 2016.

PARTICIPANTS

All Ontarians who died of an opioid related cause.

EXPOSURE

Active opioid prescriptions, defined as those with a duration overlapping the date of death, and recent opioid prescriptions, defined as those dispensed in the 30 and 180 days preceding death. Postmortem toxicology results from the Drug and Drug/Alcohol Related Death database were used to characterise deaths on the basis of presence of prescribed and non-prescribed (that is, diverted or illicit) opioids, overall and stratified by year and age.

RESULTS

2833 opioid related deaths occurred. An active opioid prescription on the date of death was relatively common but declined slightly throughout the study period (38.2% (241/631) in 2013 and 32.5% (278/855) in 2016; P for trend=0.03). Older people and women were relatively more likely to have an active opioid prescription at time of death. In 2016, 46% (169/364) of people aged 45-64 had an active opioid prescription compared with only 12% (8/69) among those aged 24 or younger (P for trend<0.001). Similarly, 46% (124/272) of women had an active opioid prescription at time of death compared with 26.4% (154/583) of men (P<0.001). Among people with active opioid prescriptions at time of death, 37.8% (375/993) also had evidence of a non-prescribed opioid on postmortem toxicology. By 2016, the non-prescribed opioid most commonly identified after death was fentanyl (41%; 47 of 115 cases). Among people without an active opioid prescription at time of death, fentanyl was detected in 20% (78/390) of deaths in 2013, increasing to 47.5% (274/577) by 2016 (P<0.001).

CONCLUSIONS

Prescribed, diverted, and illicit opioids all play an important role in opioid related deaths. Although more than half of all opioid related deaths still involved prescription drugs (either dispensed or diverted) in 2016, the increased rate of deaths involving fentanyl between 2015 and 2016 is concerning and suggests the need for a multifactorial approach to this problem that considers both the prescribed and illicit opioid environments.

Medical Costs of Delayed Hip Fracture Surgery

BACKGROUND

Waiting for hip fracture surgery is associated with complications. The objective of this study was to determine whether waiting for hip fracture surgery is associated with health-care costs.

METHODS

We conducted a population-based, propensity-matched cohort study of patients treated between 2009 and 2014 in Ontario, Canada. The primary exposure was early hip fracture surgery, performed within 24 hours after arrival at the emergency department. The primary outcome was direct medical costs, estimated for each patient in 2013 Canadian dollars, from the payer perspective. The costs in the early and delayed groups were then compared using a difference-in-differences approach: the baseline cost in the year prior to the hip fracture that had been accrued by patients with early surgery was subtracted from the cost in the first year following the surgery (first difference), and the difference was then compared with the same difference among propensity-score-matched patients who had received delayed surgery (second difference). The secondary outcome was the postoperative length of stay (in days).

RESULTS

The study included 42,230 patients who received hip fracture surgery from a total of 522 different surgeons at 72 hospitals. The mean cost (and standard deviation) attributed to the hip fracture was $39,497 ± $46,645 per person. The matched patients who underwent surgery after 24 hours had direct 1-year medical costs that were an average of $2,638 higher (95% confidence interval [CI] = $1,595 to $3,680, p < 0.0001) and a postoperative length of stay that was an average of 0.610 day longer (95% CI = 0.1749 to 1.0331 days, p = 0.0058) compared with those who underwent surgery within 24 hours.

CONCLUSIONS

Waiting >24 hours for hip fracture surgery was associated with increased medical costs and length of stay. Costs incurred by waiting may provide a financial incentive to mitigate delays in hip fracture surgery.

LEVEL OF EVIDENCE

Economic Level III. Please see Instructions for Authors for a complete description of levels of evidence.

Reporting and evaluating wait times for urgent hip fracture surgery in Ontario, Canada

BACKGROUND

Although a delay of 24 hours for hip fracture repair is associated with medical complications and costs, it is unknown how long patients wait for surgery for hip fracture. We describe novel methods for measuring exact urgent and emergent surgical wait times (in hours) and the factors that influence them.

METHODS

Adults aged 45 years and older who underwent surgery for hip fracture (the most common urgently performed procedure) in Ontario, Canada, between 2009 and 2014 were eligible. Validated data from linked health administrative databases were used. The primary outcome was the time elapsed from hospital arrival recorded in the National Ambulatory Care Reporting System until the time of surgery recorded in the Discharge Abstract Database (in hours). The influence of patient, physician and hospital factors on wait times was investigated using 3-level, hierarchical linear regression models.

RESULTS

Among 42 230 patients with hip fracture, the mean (SD) wait time for surgery was 38.76 (28.84) hours, and 14 174 (33.5%) patients underwent surgery within 24 hours. Variables strongly associated with delay included time for hospital transfer (adjusted increase of 26.23 h, 95% CI 25.38 to 27.01) and time for preoperative echocardiography (adjusted increase of 18.56 h, 95% CI 17.73 to 19.38). More than half of the hospitals (37 of 72, 51.4%), compared with 4.8% of surgeons and 0.2% of anesthesiologists, showed significant differences in the risk-adjusted likelihood of delayed surgery.

INTERPRETATION

Exact wait times for urgent and emergent surgery can be measured using Canada's administrative data. Only one-third of patients received surgery within the safe time frame (24 h). Wait times varied according to hospital and physician factors; however, hospital factors had a larger impact.

The Burden of Opioid-Related Mortality in the United States

IMPORTANCE

Opioid prescribing and overdose are leading public health problems in North America, yet the precise public health burden has not been quantified.

OBJECTIVE

To examine the burden of opioid-related mortality across the United States over time.

DESIGN, SETTING, AND PARTICIPANTS

This study used a serial cross-sectional design in which cross sections were examined at different time points to investigate deaths from opioid-related causes in the United States between January 1, 2001, and December 31, 2016.

MAIN OUTCOMES AND MEASURES

Opioid-related deaths, defined as those in which a prescription or illicit opioid contributed substantially to an individual's cause of death as determined by death certificates. We compared the percentage of deaths attributable to opioids and the associated person-years of life lost by age group.

RESULTS

Between 2001 and 2016, the number of opioid-related deaths in the United States increased by 345%, from 9489 to 42 245 deaths (33.3 to 130.7 deaths per million population). By 2016, men accounted for 67.5% of all opioid-related deaths, and the median (interquartile range) age at death was 40 (30-52) years. The percentage of deaths attributable to opioids increased in a similar fashion. In 2001, 0.4% of deaths (1 in 255) were opioid related, rising to 1.5% of deaths (1 in 65) by 2016, an increase of 292%. This burden was highest among adults aged 24 to 35 years. In this age group, 20.0% of deaths were attributable to opioids in 2016. Among those aged 15 to 24 years, 12.4% of deaths were attributable to opioids in 2016. Overall, opioid-related deaths resulted in 1 681 359 years of life lost (5.2 per 1000 population) in the United States in 2016, most of which (1 125 711 years of life lost) were among men. Adults aged 25 to 34 years had 12.9 years of life lost per 1000 population, and those aged 35 to 44 years had 9.9 years of life lost per 1000 population.

CONCLUSIONS AND RELEVANCE

Premature death from opioid-related causes imposes an enormous public health burden across the United States. The recent increase in deaths attributable to opioids among those aged 15 to 34 years highlights a need for targeted programs and policies that focus on improved addiction care and harm reduction measures in this high-risk population.

Utilization and Short-Term Outcomes of Primary Total Hip and Knee Arthroplasty in the United States and Canada: An Analysis of New York and Ontario Administrative Data

OBJECTIVE

Total knee arthroplasty (TKA) and total hip arthroplasty (THA) are common and effective surgical procedures. This study sought to compare utilization and short-term outcomes of primary TKA and THA in adjacent regions of Canada and the United States.

METHODS

The study was designed as a retrospective cohort study of patients who underwent primary TKA or THA, comparing administrative data from New York and Ontario in 2012-2013. Demographic features of the TKA and THA patients, per capita utilization rates, and short-term outcomes were compared between the jurisdictions.

RESULTS

A higher percentage of New York hospitals performed TKA compared to Ontario hospitals (75.7% versus 42.1%; P < 0.001), and the mean annual procedural volume for TKAs was lower in New York hospitals (mean 179 versus 327 in Ontario hospitals; P < 0.001). After direct standardization, utilization was significantly lower in New York compared to Ontario, both for TKA (16.1 TKAs versus 21.4 TKAs per 10,000 population per year; P < 0.001) and for THA (10.5 THAs versus 11.5 THAs per 10,000 population per year; P < 0.001). For those who underwent TKA, the length of stay in Ontario hospitals was significantly longer (mean 3.7 days versus 3.4 days in New York hospitals; P < 0.001). A smaller percentage of New York patients were discharged directly home (46.2% versus 90.9% of Ontario patients; P < 0.001), but 30-day and 90-day readmission rates were higher in New York compared to Ontario (30-day rates, 4.6% versus 3.9% [P < 0.001]; 90-day rates, 8.4% versus 6.7% [P < 0.001]). For the THA cohorts, the results with regard to length of stay, discharge disposition, and readmission rates were similar to those for TKA.

CONCLUSION

Ontario has higher utilization of total joint arthroplasty than New York but has a smaller percentage of hospitals performing these procedures. Patients are more likely to be discharged home and less likely to be readmitted in Ontario. Our results suggest areas where each jurisdiction could improve.

Trends and uptake of new formulations of controlled-release oxycodone in Canada

Purpose

This study investigated the impact of changing availability of tamper‐deterrent and non‐tamper‐deterrent oxycodone on prescribing patterns of controlled‐release oxycodone across Canada.

Methods

We conducted a population‐based, serial cross‐sectional study of controlled‐release oxycodone dispensing from community pharmacies across Canada between October 2007 and April 2016. We calculated rates of dispensing (tablets per 100 population) and reported the relative market share of generic non‐tamper‐deterrent controlled‐release oxycodone. All analyses were reported nationally and stratified by province.

Results

After the introduction of a tamper‐deterrent formulation, the national rate of controlled‐release oxycodone dispensing fell by 44.6% (from 26.4 to 14.6 tablets per 100 population from February 2012 to April 2016). Between December 2012 and July 2013, there was moderate uptake of generic non‐tamper‐deterrent controlled‐release oxycodone (968 452 tablets; 16.0% in July 2013), which appeared to have little impact on the overall rate of controlled‐release oxycodone dispensing in Canada. However, the uptake of generic non‐tamper‐deterrent oxycodone varied considerably by province. By April 2016, 55.0% of all controlled‐release oxycodone tablets dispensed in Quebec were for the generic formulation. Elsewhere in Canada, this prevalence was less than 30%, ranging between 1.6% (Prince Edward Island) and 26.9% (British Columbia) at the end of our study period.

Conclusions

The changing availability of tamper‐deterrent and non‐tamper‐deterrent formulations of controlled‐release oxycodone in Canada has had variable influence on the rate of use of these products across Canada. Future research should explore whether the availability of generic controlled‐release oxycodone has led to measurable changes in the safety of oxycodone use in Canada.

Association of Overlapping Surgery With Increased Risk for Complications Following Hip Surgery: A Population-Based, Matched Cohort Study

IMPORTANCE

Overlapping surgery, also known as double-booking, refers to a controversial practice in which a single attending surgeon supervises 2 or more operations, in different operating rooms, at the same time.

OBJECTIVE

To determine if overlapping surgery is associated with greater risk for complications following surgical treatment for hip fracture and arthritis.

DESIGN, SETTING, AND PARTICIPANTS

This was a retrospective population-based cohort study in Ontario, Canada (population, 13.6 million), for the years 2009 to 2014. There was 1 year of follow-up. This study encompassed 2 large cohorts. The "hip fracture" cohort captured all persons older than 60 years who underwent surgery for a hip fracture during the study period. The "total hip arthroplasty" (THA) cohort captured all primary elective THA recipients for arthritis during the study period. We matched overlapping and nonoverlapping hip fractures by patient age, patient sex, surgical procedure (for the hip fracture cohort), primary surgeon, and hospital.

EXPOSURES

Procedures were identified as overlapping if they overlapped with another surgical procedure performed by the same primary attending surgeon by more than 30 minutes.

MAIN OUTCOMES AND MEASURES

Complication (infection, revision, dislocation) within 1 year.

RESULTS

There were 38 008 hip fractures, and of those, 960 (2.5%) were overlapping (mean age of patients, 66 years [interquartile range, 57-74 years]; 503 [52.4%] were female). There were 52 869 THAs and of those, 1560 (3.0%) overlapping (mean age, 84 years [interquartile range, 77-89 years]; 1293 [82.9%] were female). After matching, overlapping hip fracture procedures had a greater risk for a complication (hazard ratio [HR], 1.85; 95% CI, 1.27-2.71; P = .001), as did overlapping THA procedures (HR, 1.79; 95% CI, 1.02-3.14; P = .04). Among overlapping hip fracture operations, increasing duration of operative overlap was associated with increasing risk for complications (adjusted odds ratio, 1.07 per 10-minute increase in overlap; P = .009).

CONCLUSIONS AND RELEVANCE

Overlapping surgery was relatively rare but was associated with an increased risk for surgical complications. Furthermore, increasing duration of operative overlap was associated with an increasing risk for complications. These findings support the notion that overlapping provision of surgery should be part of the informed consent process.

Senior high-cost healthcare users' resource utilization and outcomes: a protocol of a retrospective matched cohort study in Canada

INTRODUCTION

Senior high-cost users (HCUs) are estimated to represent 60% of all HCUs in Ontario, Canada's most populous province. To improve our understanding of individual and health system characteristics related to senior HCUs, we will examine incident senior HCUs to determine their incremental healthcare utilisation and costs, characteristics of index hospitalisation episodes, mortality and their regional variation across Ontario.

METHODS AND ANALYSIS

A retrospective, population-based cohort study using administrative healthcare records will be used. Incident senior HCUs will be defined as Ontarians aged ≥66 years who were in the top 5% of healthcare cost users during fiscal year 2013 but not during fiscal year 2012. Each HCU will be matched to three non-HCUs by age, sex and health planning region. Incremental healthcare use and costs will be determined using the method of recycled predictions. We will apply multivariable logistic regression to determine patient and health service factors associated with index hospitalisation and inhospital mortality during the incident year. The most common causes of admission will be identified and contrasted with the most expensive hospitalised conditions. We will also calculate the ratio of inpatient costs incurred through admissions of ambulatory care sensitive conditions to the total inpatient expenditures. The magnitude of variation in costs and health service utilisation will be established by calculating the extremal quotient, the coefficient of variation and the Gini mean difference for estimates obtained through multilevel regression analyses.

ETHICS AND DISSEMINATION

This study has been approved by Hamilton Integrated Research Ethics Board (ID#1715-C). The results of the study will be distributed through peer-reviewed journals. They also will be disseminated at research events in academic settings, national and international conferences as well as with presentations to provincial health authorities.

Association Between Wait Time and 30-Day Mortality in Adults Undergoing Hip Fracture Surgery

IMPORTANCE

Although wait times for hip fracture surgery have been linked to mortality and are being used as quality-of-care indicators worldwide, controversy exists about the duration of the wait that leads to complications.

OBJECTIVE

To use population-based wait-time data to identify the optimal time window in which to conduct hip fracture surgery before the risk of complications increases.

DESIGN, SETTING, AND PARTICIPANTS

Population-based, retrospective cohort study of adults undergoing hip fracture surgery between April 1, 2009, and March 31, 2014, at 72 hospitals in Ontario, Canada. Risk-adjusted restricted cubic splines modeled the probability of each complication according to wait time. The inflection point (in hours) when complications began to increase was used to define early and delayed surgery. To evaluate the robustness of this definition, outcomes among propensity-score matched early and delayed surgical patients were compared using percent absolute risk differences (RDs, with 95% CIs).

EXPOSURE

Time elapsed from hospital arrival to surgery (in hours).

MAIN OUTCOMES AND MEASURES

Mortality within 30 days. Secondary outcomes included a composite of mortality or other medical complications (myocardial infarction, deep vein thrombosis, pulmonary embolism, and pneumonia).

RESULTS

Among 42 230 patients with hip fracture (mean [SD] age, 80.1 years [10.7], 70.5% women) who met study entry criteria, overall mortality at 30 days was 7.0%. The risk of complications increased when wait times were greater than 24 hours, irrespective of the complication considered. Compared with 13 731 propensity-score matched patients who received surgery earlier, 13 731 patients who received surgery after 24 hours had a significantly higher risk of 30-day mortality (898 [6.5%] vs 790 [5.8%]; % absolute RD, 0.79; 95% CI, 0.23-1.35) and the composite outcome (1680 [12.2%]) vs 1383 [10.1%]; % absolute RD, 2.16; 95% CI, 1.43-2.89).

CONCLUSIONS AND RELEVANCE

Among adults undergoing hip fracture surgery, increased wait time was associated with a greater risk of 30-day mortality and other complications. A wait time of 24 hours may represent a threshold defining higher risk.

Changes in the dispensing of opioid medications in Canada following the introduction of a tamper-deterrent formulation of long-acting oxycodone: a time series analysis

BACKGROUND

In February 2012, a reformulated tamper-deterrent form of long-acting oxycodone, OxyNeo, was introduced in Canada. We investigated the impact of the introduction of OxyNeo on patterns of opioid prescribing.

METHODS

We conducted population-based, cross-sectional analyses of opioid dispensing in Canada between 2008 and 2016. We estimated monthly community pharmacy dispensing of oral formulations of codeine, morphine, hydromorphone and oxycodone, and a transdermal formulation of fentanyl, and converted quantities to milligrams of morphine equivalents (MMEs) per 1000 population. We used time series analysis to evaluate the effect of the introduction of OxyNeo on these trends.

RESULTS

National dispensing of long-acting opioids fell by 14.9% between February 2012 and April 2016, from 36 098 MMEs to 30 716 MMEs per 1000 population (p < 0.01). This effect varied across Canada and was largest in Ontario (reduction of 22.8%) (p = 0.01) and British Columbia (reduction of 30.0%) (p = 0.01). The national rate of oxycodone dispensing fell by 46.4% after the introduction of OxyNeo (p < 0.001); this was partially offset by an increase of 47.8% in hydromorphone dispensing (p < 0.001). Although dispensing of immediate-release opioids was a substantial contributor to overall population opioid exposure across Canada, it was unaffected by the introduction of OxyNeo (p > 0.05 in all provinces).

INTERPRETATION

The findings suggest that the introduction of a tamper-deterrent formulation of long-acting oxycodone in Canada, against a background of changing public drug benefits, was associated with sustained changes in selection of long-acting opioids but only small changes in the quantity of long-acting opioids dispensed. This illustrates the limited effect a tamper-deterrent formulation and associated coverage policy can have when other, non-tamper-deterrent alternatives are readily available.

Comparative safety of direct oral anticoagulants and warfarin in venous thromboembolism: multicentre, population based, observational study

Objective To determine the safety of direct oral anticoagulant (DOAC) use compared with warfarin use for the treatment of venous thromboembolism.Design Retrospective matched cohort study conducted between 1 January 2009 and 31 March 2016.Setting Community based, using healthcare data from six jurisdictions in Canada and the United States.Participants 59 525 adults (12 489 DOAC users; 47 036 warfarin users) with a new diagnosis of venous thromboembolism and a prescription for a DOAC or warfarin within 30 days of diagnosis.Main outcome measures Outcomes included hospital admission or emergency department visit for major bleeding and all cause mortality within 90 days after starting treatment. Propensity score matching and shared frailty models were used to estimate adjusted hazard ratios of the outcomes comparing DOACs with warfarin. Analyses were conducted independently at each site, with meta-analytical methods used to estimate pooled hazard ratios across sites.Results Of the 59 525 participants, 1967 (3.3%) had a major bleed and 1029 (1.7%) died over a mean follow-up of 85.2 days. The risk of major bleeding was similar for DOAC compared with warfarin use (pooled hazard ratio 0.92, 95% confidence interval 0.82 to 1.03), with the overall direction of the association favouring DOAC use. No difference was found in the risk of death (pooled hazard ratio 0.99, 0.84 to 1.16) for DOACs compared with warfarin use. There was no evidence of heterogeneity across centres, between patients with and without chronic kidney disease, across age groups, or between male and female patients.Conclusions In this analysis of adults with incident venous thromboembolism, treatment with DOACs, compared with warfarin, was not associated with an increased risk of major bleeding or all cause mortality in the first 90 days of treatment.Trial registration Clinical trials NCT02833987.

Real-world health care utilization and effectiveness of omalizumab for the treatment of severe asthma

BACKGROUND

Omalizumab is indicated for the treatment of moderate to severe asthma. There is limited observational evidence on the costs and effectiveness of omalizumab.

OBJECTIVE

To examine the costs and effectiveness of omalizumab for treatment of severe asthma relative to nonusers.

METHODS

We conducted a within-person repeated-measures matched cohort study in Ontario, Canada from April 1, 2012 to March 31, 2014. Continuous users of omalizumab were matched with up to 4 nonusers according to age, sex, recent specialist visits, oral corticosteroid use, asthma severity, and Charlson comorbidity score. The primary outcome was direct health care costs. Secondary outcomes were asthma-related hospitalizations or emergency department visits and oral corticosteroid use. The association between omalizumab use and each outcome was assessed using mixed-effects models adjusting for confounders.

RESULTS

Ninety-five omalizumab users and 352 nonusers were matched. Among users, there was a significant increase in health care costs of $1,796 per person owing to the cost of the medication at treatment initiation (P < .0001). Costs did not change significantly among nonusers ($85 increase in average monthly costs per person; P = .59). We found no significant changes in the rates of asthma-related hospitalizations or emergency department visits among omalizumab users (P = .44) or nonusers (P = .99) between pre- and postintervention periods.

CONCLUSION

The use of omalizumab was associated with increased costs but no evidence of lower rates of clinically important outcomes. These results suggest omalizumab had limited effectiveness in our study population. Future studies should further explore subsets of patients most likely to benefit from omalizumab therapy.

Gabapentin, opioids, and the risk of opioid-related death: A population-based nested case-control study

BACKGROUND

Prescription opioid use is highly associated with risk of opioid-related death, with 1 of every 550 chronic opioid users dying within approximately 2.5 years of their first opioid prescription. Although gabapentin is widely perceived as safe, drug-induced respiratory depression has been described when gabapentin is used alone or in combination with other medications. Because gabapentin and opioids are both commonly prescribed for pain, the likelihood of co-prescription is high. However, no published studies have examined whether concomitant gabapentin therapy is associated with an increased risk of accidental opioid-related death in patients receiving opioids. The objective of this study was to investigate whether co-prescription of opioids and gabapentin is associated with an increased risk of accidental opioid-related mortality.

METHODS AND FINDINGS

We conducted a population-based nested case-control study among opioid users who were residents of Ontario, Canada, between August 1, 1997, and December 31, 2013, using administrative databases. Cases, defined as opioid users who died of an opioid-related cause, were matched with up to 4 controls who also used opioids on age, sex, year of index date, history of chronic kidney disease, and a disease risk index. After matching, we included 1,256 cases and 4,619 controls. The primary exposure was concomitant gabapentin use in the 120 days preceding the index date. A secondary analysis characterized gabapentin dose as low (<900 mg daily), moderate (900 to 1,799 mg daily), or high (≥1,800 mg daily). A sensitivity analysis examined the effect of concomitant nonsteroidal anti-inflammatory drug (NSAID) use in the preceding 120 days. Overall, 12.3% of cases (155 of 1,256) and 6.8% of controls (313 of 4,619) were prescribed gabapentin in the prior 120 days. After multivariable adjustment, co-prescription of opioids and gabapentin was associated with a significantly increased odds of opioid-related death (odds ratio [OR] 1.99, 95% CI 1.61 to 2.47, p < 0.001; adjusted OR [aOR] 1.49, 95% CI 1.18 to 1.88, p < 0.001) compared to opioid prescription alone. In the dose-response analysis, moderate-dose (OR 2.05, 95% CI 1.46 to 2.87, p < 0.001; aOR 1.56, 95% CI 1.06 to 2.28, p = 0.024) and high-dose (OR 2.20, 95% CI 1.58 to 3.08, p < 0.001; aOR 1.58, 95% CI 1.09 to 2.27, p = 0.015) gabapentin use was associated with a nearly 60% increase in the odds of opioid-related death relative to no concomitant gabapentin use. As expected, we found no significant association between co-prescription of opioids and NSAIDs and opioid-related death (OR 1.11, 95% CI 0.98 to 1.27, p = 0.113; aOR 1.14, 95% CI 0.98 to 1.32, p = 0.083). In an exploratory analysis of patients at risk of combined opioid and gabapentin use, we found that 46.0% (45,173 of 98,288) of gabapentin users in calendar year 2013 received at least 1 concomitant prescription for an opioid. This study was limited to individuals eligible for public drug coverage in Ontario, we were only able to identify prescriptions reimbursed by the government and dispensed from retail pharmacies, and information on indication for gabapentin use was not available. Furthermore, as with all observational studies, confounding due to unmeasured variables is a potential source of bias.

CONCLUSIONS

In this study we found that among patients receiving prescription opioids, concomitant treatment with gabapentin was associated with a substantial increase in the risk of opioid-related death. Clinicians should consider carefully whether to continue prescribing this combination of products and, when the combination is deemed necessary, should closely monitor their patients and adjust opioid dose accordingly. Future research should investigate whether a similar interaction exists between pregabalin and opioids.

Prevalence and characteristics of opioid-related deaths involving alcohol in Ontario, Canada

BACKGROUND

While it is well known that patients receiving opioids should refrain from alcohol consumption, little is known about the involvement of alcohol in opioid-related deaths.

METHODS

We conducted a population-based analysis of opioid-related deaths in Ontario with and without alcohol involvement between 1993 and 2013, and reported rates overall and stratified by manner of death. We compared the characteristics of individuals who died of an opioid overdose based on the presence or absence of alcohol involvement.

RESULTS

The rate of opioid-related deaths increased 288% from 11.9 per million (95% confidence interval (CI) 9.8-13.9 per million) in 1993-46.2 per million (95% CI 42.6-49.8 per million) in 2013. The rate of opioid-related deaths without alcohol involvement increased 388% from 7.4 per million to 36.1 per million, while deaths involving alcohol increased by 125% from 4.5 per million to 10.1 per million. Therefore, although the annual number of opioid-related deaths involving alcohol rose, the proportion of opioid-related deaths involving alcohol declined from 37.8% in 1993-21.9% by 2013. Generally, opioid-related deaths involving alcohol were less likely to involve other central nervous system depressants, and more likely to occur among men and those with a history of alcohol use disorder.

CONCLUSIONS

Although the relative contribution of alcohol in opioid-related deaths has declined, 1 in 5 fatal opioid overdoses still involved alcohol in 2013. Our findings highlight the ongoing need for targeted messaging around risks of opioids alone, and in combination with alcohol and other CNS depressants.