Pain with neuropathic characteristics after surgically treated lower limb fractures: cost analysis and pain medication use

Introduction: Neuropathic pain is prevalent among people after lower limb fracture surgery, and is associated with lower health-related quality-of-life and greater disability. This study estimates the financial cost and pain medication use associated with neuropathic pain in this group. Methods: A secondary analysis using pain data collected over six postoperative months from participants randomised in the Wound Healing in Surgery for Trauma (WHiST) trial. Pain states were classified as painfree, chronic non-neuropathic pain (NNP) or chronic neuropathic pain (NP). Cost associated with each pain state from a UK National Health Service (NHS) and personal social services (PSS) perspective were estimated by multivariate models based on multiple imputed data. Pain medication usage was analysed by pain state. Results: A total of 934 participants who provided either three- or six-months pain data were included. Compared to participants with NP, those with NNP (adjusted mean difference -£730, p=0.38, 95%CI -2368 to 908) or were pain-free (adjusted mean difference -£716, p=0.53, 95%CI -2,929 to 1,497) had lower costs from the NHS and PSS perspective in the first three postoperative months. Over the first three postoperative months almost a third of participants with NP were prescribed opioids, 8% were prescribed NP medications. Similar trends were observed by six months postoperatively. Conclusion: This study found healthcare costs were higher amongst those with chronic NP compared to those who were pain-free or had chronic NNP. Opioids, rather than neuropathic pain medications, were commonly prescribed for NP over the first six postoperative months, contrary to clinical guidelines.