Benzodiazepine receptor agonist dispensations in Alberta: a population-based descriptive study

The epidemiology of benzodiazepine-related toxicity in Ontario, Canada: a population-based descriptive study

OBJECTIVES

Despite the widespread use of prescription benzodiazepines, there are few studies examining trends and patterns of benzodiazepine-related toxicity. We describe the epidemiology of benzodiazepine-related toxicity in Ontario, Canada.

METHODS

We conducted a population-based, cross-sectional study of Ontario residents who had an emergency department visit or hospitalization for benzodiazepine-related toxicity between January 1, 2013 and December 31, 2020. We reported annual crude and age-standardized rates of benzodiazepine-related toxicity overall, by age, and by sex. In each year, we characterized the history of benzodiazepine and opioid prescribing among people who experienced benzodiazepine-related toxicity, and reported the percentage of encounters with opioid, alcohol, or stimulant co-involvement.

RESULTS

Between 2013 and 2020, there were 32,674 benzodiazepine-related toxicity encounters among 25,979 Ontarians. During this period, the crude rate of benzodiazepine-related toxicity declined overall, from 28.0 to 26.1 per 100,000 population (age-standardized rate: 27.8 to 26.4 per 100,000), but increased among young adults aged 19 to 24 (39.9 to 66.6 per 100,000 population). Moreover, by 2020, the percentage of encounters associated with active benzodiazepine prescriptions had declined to 48.9%, while the percentage of encounters that had opioid, stimulant, or alcohol co-involvement rose to 28.8%.

CONCLUSION

Benzodiazepine-related toxicity has declined in Ontario overall, but has increased among youth and young adults. Furthermore, there is growing co-involvement of opioids, stimulants, and alcohol, which may reflect the recent emergence of benzodiazepines in the unregulated drug supply. Multifaceted public health initiatives comprising harm reduction, mental health supports, and promotion of appropriate prescribing are needed to reduce benzodiazepine-related harm.

Predicting 30-day risk from benzodiazepine/Z-drug dispensations in older adults using administrative data: A prognostic machine learning approach

OBJECTIVE

To develop a machine-learning (ML) model using administrative data to estimate risk of adverse outcomes within 30-days of a benzodiazepine (BZRA) dispensation in older adults for use by health departments/regulators.

DESIGN, SETTING AND PARTICIPANTS

This study was conducted in Alberta, Canada during 2018-2019 in Albertans 65 years of age and older. Those with any history of malignancy or palliative care were excluded.

EXPOSURE

Each BZRA dispensation from a community pharmacy served as the unit of analysis.

MAIN OUTCOMES AND MEASURES

ML algorithms were developed on 2018 administrative data to predict risk of any-cause hospitalization, emergency department visit or death within 30-days of a BZRA dispensation. Validation on 2019 administrative data was done using XGBoost to evaluate discrimination, calibration and other relevant metrics on ranked predictions. Daily and quarterly predictions were simulated on 2019 data.

RESULTS

65,063 study participants were included which represented 633,333 BZRA dispensation during 2018-2019. The validation set had 314,615 dispensations linked to 55,928 all-cause outcomes representing a pre-test probability of 17.8%. C-statistic for the XGBoost model was 0.75. Measuring risk at the end of 2019, the top 0.1 percentile of predicted risk had a LR + of 40.31 translating to a post-test probability of 90%. Daily and quarterly classification simulations resulted in uninformative predictions with positive likelihood ratios less than 10 in all risk prediction categories. Previous history of admissions was ranked highest in variable importance.

CONCLUSION

Developing ML models using only administrative health data may not provide health regulators with sufficient informative predictions to use as decision aids for potential interventions, especially if considering daily or quarterly classifications of BZRA risks in older adults. ML models may be informative for this context if yearly classifications are preferred. Health regulators should have access to other types of data to improve ML prediction.

Characterisation of concurrent use of prescription opioids and benzodiazepine/Z-drugs in Alberta, Canada: a population-based study

OBJECTIVE

The objective of this study is to characterise concurrent use of benzodiazepine receptor modulators and opioids among prescription opioid users in Alberta in 2017.

DESIGN

A population based retrospective study.

SETTING

Alberta, Canada, in the year 2017.

PARTICIPANTS

All individuals in Alberta, Canada, with at least one dispensation record from a community pharmacy for an opioid in the year 2017.

EXPOSURE

Concurrent use of a benzodiazepine receptor modulator and opioid, defined as overlap of supply for both drugs for at least 1 day.

MAIN OUTCOME MEASURES

Prevalence of concurrency was estimated among subgroups of patient characteristics that were considered clinically relevant or associated with inappropriate medication use.

RESULTS

Among the 547 709 Albertans who were dispensed opioid prescriptions in 2017, 132 156 (24%) also received prescriptions for benzodiazepine receptor modulators. There were 96 581 (17.6%) prescription opioid users who concurrently used benzodiazepine receptor modulators with an average of 98 days (SD=114, 95% CI 97 to 99) of total cumulative concurrency and a median of 37 days (IQR 10 to 171). The average longest duration of consecutive days of concurrency was 45 (SD=60, 95% CI 44.6 to 45.4) with a median of 24 days (IQR 8 to 59). Concurrency was more prevalent in females, patients using an average daily oral morphine equivalent >90 mg, opioid dependence therapy patients, chronic opioid users, patients utilising a high number of unique providers, lower median household incomes and those older than 65 (p value<0.001 for all comparisons).

CONCLUSIONS

Concurrent prescribing of opioids and benzodiazepine receptor modulators is common in Alberta despite the ongoing guidance of many clinical resources. Older patients, those taking higher doses of opioids, and for longer durations may be at particular risk of adverse outcomes and may be worthy of closer follow-up for assessment for dose tapering or discontinuations. As well, those with higher healthcare utilisation (seeking multiple providers) should also be closely monitored. Continued surveillance of concurrent use of these medications is warranted to ensure that safe drug use recommendations are being followed by health providers.