PSY30 - Management Of Spinal Cord Injury-Associated Neuropathic Pain With Pregabalin Is Cost-Effective Over Gabapentin

Abstract

Neuropathic pain (NeP) affects more than 75% of the spinal cord injury (SCI) patients. Nearly half of the SCI patients in the United States were prescribed gabapentin for management of NeP even though gabapentin is not indicated for NeP. Pregabalin is indicated for NeP in the UK and United States, but only 16% of the SCI patients in the United States were prescribed pregabalin. This study evaluates cost-effectiveness of pregabalin and gabapentin in management of NeP from the societal perspective. We have used a Markov model to simulate costs and effectiveness for 1,000 patients treated with placebo, pregabalin and gabapentin over a 5-year period with a monthly cycle. Transition probabilities for placebo and pregabalin were estimated based on a double-blind, randomized controlled trial. High-quality clinical data for gabapentin effectiveness is not available and thus transition probabilities for gabapentin were calculated from published literature listing gabapentin-refractory NeP patients that respond to pregabalin. Both pregabalin and gabapentin were more effective and less costly compared to the placebo treatment. The quality-adjusted life years (QALYs) for SCI patients with NeP in the placebo, gabapentin and pregabalin groups were 0.49, 0.533, and 0.543, respectively. The incremental cost effectiveness ratio (ICER) for pregabalin versus gabapentin was $104,108 (US$, 2012). The model suggests that a modest change (5% reduction) in indirect costs with pregabalin treatment reduces the ICER to $31,096. One-way sensitivity analyses show that the model is most sensitive to pregabalin’s efficacy at alleviating NeP in gabapentin-refractory SCI patients, and utility scores for the four NeP-severity health states in SCI patients. The model also shows that changes in the direct and indirect costs associated with the four health states are inconsequential. Pregabalin is cost-effective as a first-line treatment for SCI-associated NeP in the United States provided that there is a pregabalin treatment-specific reduction in indirect costs.