OBJECTIVES

The increasing prevalence of prescription opioid use among patients with chronic non-cancer pain (CNCP) has become a major public health concern. Existing protocol-driven studies have limitations in assessing the effectiveness of therapies and there is a need to identify real-world studies from diverse population of patients on their use and effectiveness of opioids and non-opioids in CNCP.

METHODS

A systematic review using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted from 1997 to 2017 in PubMed, PsycINFO and EMBASE databases. Observational studies including retrospective cohort, case-control, cross-sectional and longitudinal studies involving patients with CNCP and above 18 years of age were included in the review.

RESULTS

A total of 369 articles were identified of which 23 studies met the inclusion/exclusion criteria. All but two studies (n = 21, 91.3%) were conducted in the United States. Majority of the studies utilized administrative claims data (n = 15, 65.21%) followed by electronic medical record (n = 3, 13.04 %) and survey (n = 2, 8.7%). Few studies (n = 8, 34.8%) evaluated the use of opioids in patients with CNCP with a history of substance use or mental health disorder, or with other conditions like epilepsy and HIV/AIDS. Opioid drug overdose risk was higher in patients with depression and those receiving high morphine equivalent dose or long-acting opioids. Major limitations of the studies included uncertainty over actual consumption of prescribed medicines, inability to assess degree of impairment of painful conditions and mood disorders; and inability to distinguish between prevalent and incident opioid users.

CONCLUSIONS

Opioids were prescribed with various concomitant drugs including benzodiazepines, anticonvulsants, antidepressants in several studies. There is a need to further explore patient factors such as pain severity and psychiatric diagnosis that predict the use of opioids and non-opioids in CNCP.