Validity and responsiveness of EuroQol-5 dimension (EQ-5D) versus Short Form-6 dimension (SF-6D) questionnaire in chronic pain.

BACKGROUND: Assessments of health-related quality of life and particularly utility values are important components of health economic analyses. Several instruments have been developed to measure utilities. However no consensus has emerged regarding the most appropriate instrument within a therapeutic area such as chronic pain. The study compared two instruments - EQ-5D and SF-6D - for their performance and validity in patients with chronic pain. METHODS: Pooled data from three randomised, controlled clinical trials with two active treatment groups were used. The included patients suffered from osteoarthritis knee pain or low back pain. Differences between the utility measures were compared in terms of mean values at baseline and endpoint, Bland-Altman analysis, correlation between the dimensions, construct validity, and responsiveness. RESULTS: The analysis included 1977 patients, most with severe pain on the Numeric Rating Scale. The EQ-5D showed a greater mean change from baseline to endpoint compared with the SF-6D (0.43 to 0.58 versus 0.59 to 0.64). Bland-Altman analysis suggested the difference between two measures depended on the health status of a patient. Spearmans rank correlation showed moderate correlation between EQ-5D and SF-6D dimensions. Construct validity showed both instruments could differentiate between patient subgroups with different severities of adverse events and analgesic efficacies but larger differences were detected with the EQ-5D. Similarly, when anchoring the measures to a disease-specific questionnaire - Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) - both questionnaires could differentiate between WOMAC severity levels but the EQ-5D showed greater differences. Responsiveness was also higher with the EQ-5D and for the subgroups in which improvements in health status were expected or when WOMAC severity level was reduced the improvements with EQ-5D were higher than with SF-6D. CONCLUSIONS: This analysis showed that the mean EQ-5D scores were lower than mean SF-6D scores in patients with chronic pain. EQ-5D seemed to have higher construct validity and responsiveness in these patients.

Patient-relevant outcomes and health-related quality of life in patients with chronic, severe, noncancer pain treated with tapentadol prolonged release-Using criteria of health technology assessment.

OBJECTIVE: To perform a systematic comparison of tapentadol prolonged release (PR) and oxycodone controlled release (CR) using patient-relevant endpoints of efficacy, safety, and health-related quality of life (HRQoL) according to criteria used in health technology assessment. To derive a minimal important difference (MID) for the EQ-5D from three pivotal trials to measure patient-relevant changes in HRQoL. DESIGN: Randomized, double-blind, placebo and active controlled. SETTING: Outpatient primary care. PARTICIPANTS: Patients with severe chronic osteoarthritis pain (two pivotal studies) and severe lower-back pain (one pivotal study) were enrolled. The intent-to-treat population of the three studies comprised a total of 2,968 patients (tapentadol PR arms: 978, oxycodone CR arms: 999, and in the placebo arms: 991). INTERVENTIONS: Tapentadol PR (100-250 mg bid), oxydodone CR (20-50 mg bid), or placebo over a period of 15 weeks (3 weeks titration plus 12 weeks maintenance). OUTCOME MEASURES: Patient-relevant endpoints of efficacy, safety, tolerability, and HRQoL. RESULTS: Tapentadol PR demonstrated significant added benefits as compared to oxycodone CR in meta-analyses of the patient-relevant outcomes 30 percent pain relief (Realtive risk [RR]: 0.80 [0.75, 0.87]), treatment discontinuations (RR: 0.55 [0.363, 0.825]), safety (RR: 0.652 [0.599, 0.710]), and HRQoL (RR: 0.78 [0.64, 0.96]) based on a MID derived for the EQ-5D summary index. CONCLUSIONS: Added benefit of tapentadol in all endpoint categories suggests that it may be beneficial to initiate treatment of chronic severe nonmalignant pain with tapentadol rather than oxycodone.