The Impact of Childhood Emotional Abuse on Pain Interference Among People with Chronic Pain who Inject Drugs in Vancouver, Canada.

OBJECTIVE: High levels of chronic pain interference with daily activities are known to negatively impact quality of life. Although mental health conditions have been associated with pain interference and child abuse, research has been mixed regarding it acting as a mediator, with even less known among people who inject drugs. Therefore, we sought to explore childhood emotional abuse and pain interference among this population. METHODS: Data were derived from two prospective cohort studies of community-recruited people who inject drugs in Vancouver, Canada, between June 2014 and November 2016. We employed multivariable generalized estimating equations to examine the relationship between childhood emotional abuse and pain interference in the past six months. We also conducted a mediation analysis to examine whether mental health disorder diagnoses mediated this association. RESULTS: Among 822 eligible participants, 341 (41.5%) reported childhood emotional abuse. In a multivariable analysis, experiencing childhood emotional abuse remained independently associated with pain interference (adjusted odds ratio = 1.33, 95% confidence interval [CI] = 1.05-1.70) after adjusting for a range of confounders. Results from the mediation analysis yielded a statistically significant positive average causal mediation effect (ß = 0.01, 95% CI = 0.001-0.02). Approximately 12% of the effect was due to mediation. CONCLUSIONS: Our results demonstrate among people who inject drugs with chronic pain, those who experienced childhood emotional abuse were more likely to report pain interference, which was partially mediated by mental health disorder diagnosis history. These findings highlight the importance of incorporating screening and appropriate treatment for mental illness into chronic pain treatment.

Declining rates of health problems associated with crack smoking during the expansion of crack pipe distribution in Vancouver, Canada.

BACKGROUND: Crack cocaine smoking is associated with an array of negative health consequences, including cuts and burns from unsafe pipes, and infectious diseases such as HIV. Despite the well-established and researched harm reduction programs for injection drug users, little is known regarding the potential for harm reduction programs targeting crack smoking to reduce health problems from crack smoking. In the wake of recent crack pipe distribution services expansion, we utilized data from long running cohort studies to estimate the impact of crack pipe distribution services on the rates of health problems associated with crack smoking in Vancouver, Canada. METHODS: Data were derived from two prospective cohort studies of community-recruited people who inject drugs in Vancouver between December 2005 and November 2014. We employed multivariable generalized estimating equations to examine the relationship between crack pipe acquisition sources and self-reported health problems associated with crack smoking (e.g., cut fingers/sores, coughing blood) among people reported smoking crack. RESULTS: Among 1718 eligible participants, proportions of those obtaining crack pipes only through health service points have significantly increased from 7.2% in 2005 to 62.3% in 2014 (p < 0.001), while the rates of reporting health problems associated with crack smoking have significantly declined (p < 0.001). In multivariable analysis, compared to those obtaining pipes only through other sources (e.g., on the street, self-made), those acquiring pipes through health service points only were significantly less likely to report health problems from smoking crack (adjusted odds ratio: 0.82; 95% confidence interval: 0.73-0.93). CONCLUSIONS: These findings suggest that the expansion of crack pipe distribution services has likely served to reduce health problems from smoking crack in this setting. They provide evidence supporting crack pipe distribution programs as a harm reduction service for crack smokers.