A cost-consequence analysis of pregabalin versus usual care in the symptomatic treatment of refractory low back pain: sub-analysis of observational trial data from orthopaedic surgery and rehabilitation clinics

Abstract

Background: low back pain is one of the most common reasons for outpatient consultation in both the primary-care and specialized-care settings. However, few studies have explored the effect of pregabalin in this context.

Objective: to prospectively analyse the effect of adding pregabalin on costs and consequences in the treatment of refractory low back pain in routine medical practice.

Methods: a secondary analysis was carried out in patients aged >or=18 years with a 6-month history of chronic refractory low back pain who had participated in a previous prospective, naturalistic, 12-week, two-visit study (RADIO study). The analysis compared patients receiving pregabalin with those receiving usual care. Severity of pain, healthcare resources utilization, lost workday equivalents due to pain, and related cost-adjusted reductions were assessed. The year of costing for all cost data reported in the study was 2007.

Results: data from a total of 683 patients (49.5% women, mean age 55.0 years), 82.6% of whom were receiving pregabalin, were analysed. Pregabalin was associated with a higher covariable-adjusted reduction in severity of pain, i.e. mean (SD) -3.4 (2.0) compared with -2.0 (2.1) points with usual care on a 10-point neuropathic pain questionnaire (p < 0.001), and a 61.6% response rate (defined as >/=50% reduction in pain from baseline) compared with 37.3% with usual care (p < 0.001). This resulted in fewer lost workday equivalents in the pregabalin group versus usual care (27.8 vs 34.6, p = 0.002), which produced more significant adjusted reductions in indirect costs, i.e. mean (SD) -euro961.8 (euro1242.9) compared with -euro625.8 (euro1169.2) with usual care (p = 0.004). The cost of pregabalin, i.e. mean (SD) euro303.8 (euro175.8) compared with euro37.1 (euro97.0) for usual care (p < 0.001), was offset by larger reductions in the other cost components. While the adjusted total costs were substantially reduced in both groups, pregabalin-treated patients showed more significant reductions, i.e. mean (SD) -euro991.5 (euro1702.3) compared with -euro579.3 (euro2410.3) with usual care (p = 0.023).

Conclusion: compared with usual care, addition of pregabalin to existing therapy for refractory low back pain was associated with a larger reduction in pain severity and lost workday equivalents. The acquisition cost of pregabalin was offset by a higher reduction in the indirect components of cost, resulting in a significant decrease in total costs.