Prevalence of physical pain and associated mental health and prescription drug abuse among injection drug users in San Francisco

Little information exists on the daily experiences of pain among street-level injection drug users. The data reported herein are drawn from an ongoing community-based survey among street-level injection drug users in San Francisco. To date, 143 clinical assessments have been conducted, with sample characteristics as follows: 76% male, median age 35 (sd 14.5 years), and 39% white. Over 56% of the sample reported any physical pain in prior day. The overall pain rating (0-10) was in the moderate range (mean=5.4, sd=2.5). The levels of pain over the day were quite variable, ranging from 7.3 (range 0-10, sd=2.3) at its worst to 2.98 (sd=2.5) at its least. No significant differences were observed in non-medical prescription pain reliever use in the past 6 months (59% among those with pain versus 58% among those with no pain). However, those with current pain had more extensive histories of nonmedical opioid use, using on average of 87 days in the prior 6 months compared to 51 days for those with no pain (p<.001), greater use of more potent Schedule II opioids, and were less likely to tamper as a means of ingestion. High levels of physical pain were associated with greater mental health problems. No differences in health care utilization were observed between those with and without pain, indicating high rates of undertreatment. About 12% of the sample was HIV positive, though not associated with pain. The success of public health interventions must consider the role of pain given its prominence in this community.