Individual opioids, and long- versus short-acting opioids, for chronic noncancer pain: Protocol for a network meta-analysis of randomized controlled trials

Background: Opioids are frequently prescribed for the management of patients with chronic non-cancer pain (CNCP). Previous meta-analyses of efficacy and harms have combined treatment effects across all opioids; however, specific opioids, pharmacokinetic properties (ie, long acting vs short acting), or the type of formulation (ie, immediate vs extended release) may be a source of heterogeneity for pooled effects.