Determinants of trends in prescription opioid use in British Columbia, Canada, 2005-2013

Abstract

Purpose: To explore the determinants of total opioid consumption in a Canadian province, and to examine patterns of opioid dispensations by sex, age, and income quintile.

Methods: We used population-based administrative data on prescription drug dispensations in British Columbia (BC; population ~4 million). We apply an index-based approach to examine how changes in population exposure, type of opioids used, and intensity of use contributed to changes in total morphine equivalents dispensed per 1000 population.

Results: Between 2005 and 2013 in BC, opioid consumption increased by 31%, driven by longer duration of opioid therapy and by an increase in the use of stronger opioids. Consumption increased for oxycodone, hydromorphone, fentanyl, and tramadol; and declined for morphine, codeine, and other opioids. While we did not find large sex and age differences, the total level of opioid consumption was three times as high among individuals in the lowest income quintile compared to those in the highest income quintile.

Conclusions: Our findings on changes in the type of opioids used and changes in intensity of use suggest that modifications to clinical management of patients on opioid therapy may be warranted. Similar drug utilization statistics, derived from drug information systems, can be reproduced in other jurisdictions to enable a better understanding of the opioid crisis. Copyright © 2016 John Wiley & Sons, Ltd.

Keywords: administrative data; pharmacoepidemiology; prescription opioids; total morphine equivalent.