Evaluating acceptability and feasibility of a mobile health intervention to improve self-efficacy in prescription opioid tapering in patients with chronic pain: protocol for a pilot randomised, single-blind, controlled trial. - Magee M; Gholamrezaei A; McNeilage AG; Dwyer L; Sim A; Ferreira M; Darnall B; Glare P; Ashton-James C (BMJ open, 2022)