RT Journal Article
SR Electronic
T1 Cohort profile: development and characteristics of a retrospective cohort of individuals dispensed prescription opioids for non-cancer pain in British Columbia, Canada
JF BMJ Open
JO BMJ Open
FD British Medical Journal Publishing Group
SP e043586
DO 10.1136/bmjopen-2020-043586
VO 11
IS 4
A1 James Wilton
A1 Mei Chong
A1 Younathan Abdia
A1 Roy Purssell
A1 Aaron MacInnes
A1 Tara Gomes
A1 Richard C Dart
A1 Robert F Balshaw
A1 Michael Otterstatter
A1 Stanley Wong
A1 Amanda Yu
A1 Maria Alvarez
A1 Naveed Zafar Janjua
A1 Jane A Buxton
YR 2021
UL http://bmjopen.bmj.com/content/11/4/e043586.abstract
AB Purpose Prescription opioids (POs) are widely prescribed for chronic non-cancer pain but are associated with several risks and limited long-term benefit. Large, linked data sources are needed to monitor their harmful effects. We developed and characterised a retrospective cohort of people dispensed POs.Participants We used a large linked administrative database to create the Opioid Prescribing Evaluation and Research Activities cohort of individuals dispensed POs for non-cancer pain in British Columbia (BC), Canada (1996–2015). We created definitions to categorise episodes of PO use based on a review of the literature (acute, episodic, chronic), developed an algorithm for inferring clinical indication and assessed patterns of PO use across a range of characteristics.Findings to date The current cohort includes 1.1 million individuals and 3.4 million PO episodes (estimated to capture 40%–50% of PO use in BC). The majority of episodes were acute (81%), with most prescribed for dental or surgical pain. Chronic use made up 3% of episodes but 88% of morphine equivalents (MEQ). Across the acute to episodic to chronic episode gradient, there was an increasing prevalence of higher potency POs (hydromorphone, oxycodone, fentanyl, morphine), long-acting formulations and chronic pain related indications (eg, back, neck, joint pain). Average daily dose (MEQ) was similar for acute/episodic but higher for chronic episodes. Approximately 7% of the cohort had a chronic episode and chronic pain was the characteristic most strongly associated with chronic PO use. Individuals initiating a chronic episode were also more likely to have higher social/material deprivation and previous experience with a mental health condition or a problem related to alcohol or opioid use. Overall, these findings suggest our episode definitions have face validity and also provide insight into characteristics of people initiating chronic PO therapy.Future plans The cohort will be refreshed every 2 years. Future analyses will explore the association between POs and adverse outcomes.Data are available upon reasonable request. The IDEAs cohort was made possible through a multi-agency collaboration, including BCCDC, BCCDC Public Health Laboratory, BC Cancer and BC Ministry of Health. The integrated data set involved the linkage of de-identified case, laboratory testing and cancer data with health services administrative data. Authorised users have access to de-identified data based on roles and projects. Access to the de-identified data is not permitted outside of Canada. Use of the data is limited to the objectives described in the Information Sharing Plan. Individuals interested in becoming external collaborators may contact Dr Naveed Janjua (naveed.janjua@bccdc.ca). BCCDC requires all internal and external researchers with access to analytical data sets to complete annual or more frequent privacy/confidentiality and information security and awareness training, sign confidentiality forms and complete a concept note and data request.