Health-related quality of life and its predictive role for analgesic effect in patients with painful polyneuropathy.

Painful polyneuropathy is a common neuropathic pain condition. The present study describes health-related quality of life (HRQL) in a sample of patients with painful polyneuropathy of different origin and the possible predictive role of HRQL for analgesic effect. Ninety-three patients with a diagnosis of painful polyneuropathy were included in the analysis. Data were obtained from three randomised, placebo-controlled cross-over studies testing the effect of different drugs on polyneuropathic pain (St. John's wort, venlafaxine/imipramine and valproic acid). Patients completed a HRQL questionnaire (SF-36) after a drug-free baseline period and at the end of each treatment period. At baseline, all eight SF-36 scores were lower than in the normal population. No significant differences were found between SF-36 scales during placebo and treatment with valproic acid and St. John's wort. Those two drugs had not shown a pain relieving effect in former analysis. The SF-36 scale of bodily pain (BP) was improved by venlafaxine treatment (p=0.023). General health (GH) and vitality (VT) were improved under treatment with imipramine (GH: p=0.006, VT: p=0.015). In a multivariate logistic regression analysis, baseline SF-36 scores predicted subsequent response to pharmacological treatment. Results show an impaired HRQL in painful polyneuropathy and suggest that HRQL may predict response to analgesic treatment.