Background: Little is known about opioid prescribing among individuals who have survived cancer. Our aim is to examine a predominantly socio-economically disadvantaged population for differences in opioid prescribing rates among cancer survivors compared with matched controls without a prior diagnosis of cancer.
Methods: This was a retrospective population-wide matched cohort study. Starting in 2010, individuals residing in Ontario, Canada, who were 18 to 64 years of age and at least 5 years past their cancer diagnosis were matched to controls without a prior cancer diagnosis based on sex and calendar year of birth. Follow-up was terminated at any indication of cancer recurrence, second malignancy, or new cancer diagnosis. To examine the association between survivorship and the rate of opioid prescriptions, an Andersen-Gill recurrent event regression model was implemented, adjusting for numerous individual-level characteristics and also accounting for the matched design.
Results: The rate of opioid prescribing was 1.22 times higher among survivors than among their corresponding matched controls (adjusted relative rate, 1.22; 95% CI, 1.11-1.34). Individuals from lower income quintiles who were younger, were from rural neighborhoods, and had more comorbidities had significantly higher prescribing rates. Sex was not associated with prescribing rates. This increased rate of opioid prescribing was also seen among survivors who were 10 or more years past their cancer diagnosis (compared with their controls).
Conclusion: This study demonstrates substantially higher opioid prescribing rates among cancer survivors, even long after attaining survivorship. This raises concerns about the diagnosis and management of chronic pain problems among survivors stemming from their cancer diagnosis or treatment. Cancer 2017;123:4286-4293. © 2017 American Cancer Society.
Keywords: Andersen Gill recurrent event model; cancer survivors; matched cohort study; opioid prescribing rates; relative rate.
© 2017 American Cancer Society.