Development and characteristics of the Provincial Overdose Cohort in British Columbia, Canada.

INTRODUCTION: British Columbia (BC), Canada declared a public health emergency in April 2016 for opioid overdose. Comprehensive data was needed to identify risk factors, inform interventions, and evaluate response actions. We describe the development of an overdose cohort, including linkage strategy, case definitions, and data governance model, and present the resulting characteristics, including data linkage yields and case overlap among data sources. METHODS: Overdose events from hospital admissions, physician visits, poison centre and ambulance calls, emergency department visits, and coroner's data were grouped into episodes if records were present in multiple sources. A minimum of five years of universal health care records (all prescription dispensations, fee-for-service physician billings, emergency department visits and hospitalizations) were appended for each individual. A 20% random sample of BC residents and a 1:5 matched case-control set were generated. Consultation and prioritization ensured analysts worked to address questions to directly inform public health actions. RESULTS: 10,456 individuals suffered 14,292 overdoses from January 1, 2015 to Nov 30, 2016. Only 28% of overdose events were found in more than one dataset with the unique contribution of cases highest from ambulance records (32%). Compared with fatal overdoses, non-fatal events more often involved females, younger individuals (20 to 29 years) and those 60 or older. In 78% of illegal drug deaths, there was no associated ambulance response. In the year prior to first recorded overdose, 60% of individuals had at least one ED visit, 31% at least one hospital admission, 80% at least one physician visit, and 87% had filled at least one prescription in a community pharmacy. CONCLUSION: While resource-intensive to establish, a linked cohort is useful for characterizing the full extent of the epidemic, defining sub-populations at risk, and patterns of contact with the health system. Overdose studies in other jurisdictions should consider the inclusion of multiple data sources.

At-a-glance - Impact of drug overdose-related deaths on life expectancy at birth in British Columbia. / Aperçu - Impact des décès par surdose de drogue sur l'espérance de vie à la naissance en Colombie-Britannique.

We quantified the contributions of leading causes of death and drug overdose to changes in life expectancy at birth over time and inequalities by sex and socioeconomic status in British Columbia. From 2014 to 2016, life expectancy at birth declined by 0.38 years and drug overdose deaths (mainly opioid-involved) contributed a loss of 0.12 years of the decrease. The analysis also demonstrated that the higher drug overdose mortality among males and among those in lower socioeconomic status communities contributed to a differential decrease in life expectancy at birth for males and for those in the latter category.

RÉSUMÉ: Nous avons quantifié la contribution des principales causes de décès et de surdose à l'évolution de l'espérance de vie à la naissance et aux disparités en matière de sexe et de situation socioéconomique en Colombie-Britannique. Entre 2014 et 2016, l'espérance de vie à la naissance a diminué de 0,38 an et les décès par surdose (principalement liés aux opioïdes) ont contribué à ce recul pour 0,12 an. L'analyse a également montré que le taux plus élevé de mortalité par surdose constaté chez les hommes et les membres des catégories socioéconomiques plus défavorisées a contribué à une diminution différentielle dans ces deux groupes de l'espérance de vie à la naissance.

Type 1 diabetes incidence and prevalence trends in a cohort of Canadian children and youth.

BACKGROUND AND OBJECTIVE: Incidence rates of type 1 diabetes have long been on the rise across the globe, however, there is emerging evidence that the rate of rise may be slowing. The objective of this study was to describe trends in the incidence and prevalence of type 1 diabetes in a sample of Canadian children and youth. METHODS: Cases were extracted using linked administrative datasets and a validated diabetes case-finding definition. Incidence and prevalence trends were analyzed using the JoinPoint regression analysis program. RESULTS: A small increase in the incidence of type 1 diabetes was observed over the 11-year period from 2002-2003 to 2012-2013. Total incident cases per year ranged from 201 (2005-2006) to 250 (2007-2008). Total prevalent cases per year ranged from 1790 (2002-2003) to 2264 (2012-2013). Incidence was highest among children aged 5 to 14 years, and lowest in the youngest (1-4 years) and oldest (15-19 years) age brackets. The most significant increase in incidence was in children aged 10 to 14 years. Age-standardized prevalence increased significantly throughout the study period. CONCLUSION: These results are similar to data from the United States but differ from European data with respect to the annual percent change for incidence as well as age-specific incidence trends. In keeping with the low mortality rates associated with type 1 diabetes, the prevalence continues to rise.

Incidence and prevalence trends of youth-onset type 2 diabetes in a cohort of Canadian youth: 2002-2013.

OBJECTIVE: Youth-onset type 2 diabetes is an emerging disease. We estimated incidence and prevalence trends of youth-onset type 2 diabetes between 2002 and 2013 in the Canadian province of British Columbia. METHODS: This population-based cohort study used a validated diabetes case-finding definition and algorithm to differentiate type 2 from type 1 diabetes to identify youth <20 years with type 2 diabetes within linked population-based administrative data. Age-standardized incidence and prevalence were calculated. JoinPoint regression and double exponential smooth modeling were used. RESULTS: From 2002/2003 to 2012/2013, the incidence of youth-onset type 2 diabetes increased from 3.45 (95% confidence interval, CI: 2.43, 4.80) to 5.16 (95% CI: 3.86, 6.78)/100 000. The annual percent change (APC) in incidence was 3.74 (95% CI: 1.61, 5.92; P = 0.003) overall, while it was 5.94 (95% CI: 1.84, 10.20; P = 0.009) and 0.53 (95% CI: -5.04, 6.43; P = 0.837) in females and males, respectively. The prevalence increased from 0.009% (95% CI: 0.007, 0.011) in 2002/2003 to 0.021% (95% CI: 0.018, 0.024) in 2012/2013 with an APC of 7.89 (95% CI: 6.41, 9.40; P < 0.0001). In females, it increased from 0.012% (95% CI: 0.009, 0.015) to 0.027% (95% CI: 0.023, 0.032) and in males from 0.007% (95% CI: 0.005, 0.009) to 0.015% (95% CI: 0.012, 0.019). By 2030, we forecast a prevalence of 0.046% (95% CI: 0.043, 0.048). CONCLUSIONS: Youth-onset type 2 diabetes is increasing with higher rates in females vs males. If these rates continue, in 2030, the number of cases will increase by 5-fold. These data are needed to set priorities for diabetes prevention in youth.

Impact of rosiglitazone meta-analysis on use of glucose-lowering medications.

BACKGROUND: In May 2007 Nissen and Wolski reported the results of a meta-analysis showing an association between use of rosiglitazone and increased risk of myocardial infarction (N Engl J Med 2007;356(24):2457-2471). Rosiglitazone is an insulin-sensitizing agent used to control blood glucose levels in patients with type 2 diabetes. Subsequent analyses provided evidence that the meta-analysis led to a decline in new and prevalent use of rosiglitazone. We sought to evaluate the impact of the meta-analysis on patterns of use of glucose-lowering drugs and patterns of initiation, cessation and switching of drug therapy, and to estimate these effects in relation to other predictors of initiation and cessation of rosiglitazone. METHODS: We used an interrupted time series analysis to test the impact of the meta-analysis on monthly utilization of glucose-lowering drugs for the 4.3 million residents of the province of British Columbia. We used multivariate logistic regression with generalized estimating equations to test predictors of initiation and cessation of rosiglitazone, including the influence of microvascular and macrovascular comorbidities, before and after the meta-analysis. RESULTS: A comparison of predicted and observed utilization for November 2007 showed that use of rosiglitazone declined by 40% (95% confidence interval 39%-42%), whereas use of pioglitazone, insulin and sulfonylureas increased. The presence of macrovascular comorbidities strengthened both the negative impact of the meta-analysis on initiation of rosiglitazone therapy and the positive impact of the meta-analysis on cessation of this drug. INTERPRETATION: The shift in utilization from rosiglitazone to insulin and sulfonylureas and the modest increase in use of pioglitazone suggest that the latter drug was not embraced as a less harmful alternative to rosiglitazone. Macrovascular comorbidities played a greater role in decisions to start or stop rosiglitazone therapy after the meta-analysis was published.

Statin adherence and risk of accidents: a cautionary tale.

BACKGROUND: Bias in studies of preventive medications can occur when healthier patients are more likely to initiate and adhere to therapy than less healthy patients. We sought evidence of this bias by examining associations between statin exposure and various outcomes that should not be causally affected by statin exposure, such as workplace and motor vehicle accidents. METHODS AND RESULTS: We conducted a prospective cohort study of statin patients using data from British Columbia, Canada, a multiethnic society with a population of 4.3 million people. Study subjects were 141 086 patients who initiated statins for primary prevention. We examined the association between adherence and multiple outcomes such as accidents and screening procedures using multivariable-adjusted Cox proportional hazards models. The study population was 49% female and had an average age of 61 years. The results from our multivariable-adjusted models showed that more adherent patients were less likely to have accidents than less adherent patients. This effect was greatest for motor vehicle accidents (hazard ratio, 0.75; 95% confidence interval, 0.72 to 0.79) and workplace accidents (hazard ratio, 0.77; 95% confidence interval, 0.74 to 0.81). More adherent patients had a greater likelihood of using screening services (hazard ratio, 1.17; 95% confidence interval, 1.15 to 1.20) and a lower likelihood of developing other diseases likely to be unrelated to a biological affect of a statin (hazard ratio, 0.87; 95% confidence interval, 0.86 to 0.89). CONCLUSIONS: Our study contributes compelling evidence that patients who adhere to statins are systematically more health seeking than comparable patients who do not remain adherent. Caution is warranted when interpreting analyses that attribute surprising protective effects to preventive medications.