Adverse Outcomes Associated with Prescription Opioids for Acute Low Back Pain: A Systematic Review and Meta-Analysis.

Background: Acute low back pain (ALBP) is a common clinical complaint that can last anywhere from 24 hours to 12 weeks. In recent years, there has been an opioid epidemic which is linked to the increased availability of prescription opioids. Though guidelines recommend that in the treatment of ALBP, opioids should be used when other treatments fail, we have seen an increase in opioid prescriptions for ALBP. With this crisis, it is important to examine if there are any adverse outcomes associated with prescribing opioids for ALBP.

Objective: We aim to review the published literature to examine the adverse outcomes associated with opioid use for ALBP.

Study Design: We performed a systematic review with meta-analysis in accordance with our published protocol and PRISMA guidelines.

Setting: The review was conducted at McMaster University.

Methods: Various electronic databases for articles published from inception to September 30, 2017, inclusive. Both randomized clinical trials and observational studies on the impact of opioid use in ALBP in the adult population were included. Eight pairs of independent reviewers performed screening, data extraction, and assessment of methodological quality. The identified articles were assessed for risk of bias using sensitivity analysis. Trials with comparative outcomes were reported in a meta-analysis using a fixed effects model.

Results: A total of 13,889 studies were initially screened for the review and a total of 4 studies were included in the full review, of which 2 studies were meta-analyzed. Our results showed that prescribing opioids for ALBP was significantly associated with long-term continued opioid use (1.57, 95% CI, 1.06-2.33). There was no significant association found between unemployment duration and prescribing opioids for ALBP (3.54, 95% CI, -7.57 to 14.66).

Limitations: Due to the limited number of studies that considered unemployment, only an unpooled analysis was conducted. Among the included studies there was both statistical and clinical heterogeneity due to differences in methodology, study design, risk of selection or performance bias. Most of the studies had an unclear or high risk of bias and poorly defined side effects.

Conclusions: Due to the lack of literature examining long-term adverse outcomes associated with prescribing opioids for ALBP, no definitive conclusions can be made. However, with the literature available, there does seem to be risk associated with prescribing opioids for ALBP so there is a great need to conduct further investigations examining these adverse outcomes for ALBP patients.

Key Words: Acute low back pain, opioids, prescriptions, low back pain, long-term use, opioid use disorder.