Sex Differences in Overlapping Chronic Non-cancer Pain Conditions in a Tertiary Pain Clinic

Samah Hassan, Allan Gordon and Gillian Einstein

Sex differences have been reported repeatedly in pain and response to opioid analgesia with women representing the majority of chronic non-cancer pain (CNCP) patients as well as a growing population of opioid users and misusers. However, none of these reports has investigated sex differences in the prevalence of overlapping multiple pain conditions (MPC), especially among patients under opioid therapy. Two hundred eighty-three charts were reviewed of patients attending a tertiary pain clinic with multiple sub-practices in a large Canadian city over a one-year period. 201 patients suffering from CNCP and under opioid therapy were selected. A significant sex difference was found in the number of patients, while no statistically significant sex difference was found in type of opioids prescribed. Moreover, significant sex differences were found in the prevalence and types of overlapping CNCP conditions as well as in the pattern of opioid misuse. With respect to overlapping pain conditions, Chronic pelvic pain (CPP) was the most common pain condition to co-occur in women, while in men, fibromyalgia was the most common. Taken together, all of these suggest that sex differences are significant in patients with overlapp