Individual difference variables and the effects of progressive muscle relaxation and analgesic imagery interventions on cancer pain.

Clinicians in acute care settings are often called upon to manage cancer pain unrelieved by medications. Cognitive-behavioral strategies, such as relaxation and imagery, are recommended for cancer pain management; however, there appear to be individual differences in their effects. This pilot study examined variation in pain outcomes achieved with progressive muscle relaxation (PMR) and analgesic imagery interventions among hospitalized patients with cancer pain, and assessed the influence of four individual difference variables (cognitive ability, outcome expectancy, previous experience, and concurrent symptoms) on pain relief achieved with each intervention. A crossover design was used in which 40 hospitalized cancer patients received two trials of PMR, two trials of analgesic imagery, and two trials of a control condition. In comparing means between treatment and control conditions, both PMR and analgesic imagery produced greater improvements in pain intensity, pain-related distress, and perceived control over pain than the control condition. However, individual responder analysis revealed that only half of the participants achieved a clinically meaningful improvement in pain with each intervention. Patients who achieved a meaningful improvement in pain with analgesic imagery reported greater imaging ability, more positive outcome expectancy, and fewer concurrent symptoms than those who did not achieve a meaningful reduction in pain. Similar relationships were not significant for the PMR intervention. Investigators should continue efforts to identify factors that moderate the effects of cognitive-behavioral pain coping strategies so that clinicians can identify the most beneficial treatments for individual patients.