PPN4: UTILITY ASSESSMENTS OF OPIOID TREATMENT IN THE US, CANADA AND AUSTRALIA FOR PATIENTS WITH CHRONIC NON-MALIGNANT PAIN

Abstract

BACKGROUND: Optimal treatment for chronic non-malignant pain (CNMP) is largely a function of patient preferences in balancing pain control with treatment tolerability. OBJECTIVE: To estimate utilities for health states associated with CNMP and its treatment with opioids. METHODS: 96 CNMP patients (31 Canadian, 33 US, 32 Australian) completed the SF-36TM and assessed health state descriptions and their own current health using the visual analog scale and computer-assisted adaptive conjoint analysis (ACA). The health state descriptions included combinations of: presence/absence of 7 side effects (3 severity levels for each); pain control (5 severity levels); and 2 opioid administration routes. RESULTS: On average, subjects were 47 (±13) years, white (95%), female (63%), not living alone (74%), and unemployed (74%). Approximately 75% of subjects in each country were currently experiencing mild to moderate pain; most had arthritic or low back pain. All SF-36TM subscale scores by country were significantly lower than US age- and gender-equivalent norms (p < 0.05). Mean utilities did not vary substantially between oral vs. transdermal opioid administration. Overall, mean (±SE) utilities ranged from a maximum of 0.87 ± 0.02 (no pain or side effects) to a minimum of 0.18 ± 0.02 (uncontrolled pain with severe respiratory depression or severe vomiting). Mean utilities for controlled pain with moderate side effects ranged from 0.62 ± 0.02 (mood changes, vomiting, or respiratory depression) to 0.74 ± 0.02 (sweating). Uncontrolled pain without side effects (0.64 ± 0.02) was preferred to well-controlled pain with severe side effects (range: 0.41 ± 0.03 [mood changes, vomiting, or respiratory depression] to 0.54 ± 0.03 [sweating]). CONCLUSIONS: Results indicate a patient preference for opioid therapy that causes fewer side effects. Although pain may be extremely debilitating, tolerating pain to avoid opioid side effects may be preferable to controlling pain and experiencing certain opioid side effects. Opioid side effects combined with poorly-controlled pain may result in very low health utility.