Pain, psychological status, and functional recovery in chronic pain patients on daily opioids: A case comparison

Long-term opioid therapy for chronic benign pain remains controversial. Most studies on the effectiveness of such regimens have been case series or case comparisons and very few randomized placebo-controlled studies are available. Overall, this research has produced mixed results. The current study sought to further explore issues regarding the effectiveness of opioids for chronic pain and to examine the use of adjunctive medications in these patients. A random sample of 100 patients taking daily opioids (Opioid) and 100 taking no opioids (Non-opioid) at evaluation were selected from the patient population of a tertiary care multidisciplinary pain program. Statistical analyses revealed that the two groups did not differ regarding pain type, duration, location, or surgical history. Non-Caucasians were less likely to be taking opioids than Caucasians (p < 0.05). Relative to the Non-opioid group, Opioid patients were less frequently taking non-steroidal anti-inflammatories (p < 0.01) and were more often taking anxiolytics (p < 0.05) and muscle relaxants (p < 0.01). Opioid patients reported higher (p < 0.05) current pain and more frequently (p < 0.05) reported current or past clinical depression or anxiety. No other significant differences were noted on measures of pain, psychological status, or functioning. Statistical removal of the effects of pain differences did not alter the pattern of results for psychological and functional measures. Although the study design employed did not allow determination of causality, it is consistent with previous work which has failed to reveal any advantage to use of daily opioids in the chronic pain population with regard to analgesia, decreased adjunctive medication use, or functional recovery. Well-designed, prospective, randomized studies are needed, but the current results suggest continued caution in the use of daily opioids until such studies become available.