A cost-utility comparison of four first-line medications in painful diabetic neuropathy

Background: Painful diabetic neuropathy is common and adversely affects patients' quality of life and function. Several treatment options exist, but their relative efficacy and value are unknown. Objective: To determine the relative efficacy, costs and cost effectiveness of the first-line treatment options for painful diabetic neuropathy. Methods: Published and unpublished clinical trial and cross-sectional data were incorporated into a decision analytic model to estimate the net health and cost consequences of treatment for painful diabetic peripheral neuropathy over 3-month (base case), 1-month and 6-month timeframes. Efficacy was measured in QALYs, and costs were measured in $US, year 2006 values, using a US third-party payer perspective. The patients included in the model were outpatients with moderate to severe pain associated with diabetic peripheral neuropathy and no contraindications to treatment with tricyclic antidepressants. Four medications were compared: desipramine 100 mg/day, gabapentin 2400 mg/day, pregabalin 300 mg/day and duloxetine 60 mg/day. Results: Desipramine and duloxetine were both more effective and less expensive than gabapentin and pregabalin in the base-case analysis and through a wide range of sensitivity analyses. Duloxetine offered borderline value compared with desipramine in the base case ($US47 700 per QALY), but not when incorporating baseline-observation-carried-forward analyses of the clinical trial data ($US867 000 per QALY). The results were also sensitive to the probability of obtaining pain relief with duloxetine. Conclusions: Desipramine (100 mg/day) and duloxetine (60 mg/day) appear to be more cost effective than gabapentin or pregabalin for treating painful diabetic neuropathy. The estimated value of duloxetine relative to desipramine depends on the assumptions made in the statistical analyses of clinical trial data.