Quality-of-Life Improvements Associated With Reductions in Cocaine-Positive Urine Drug Screens

Objective: Objectively verified reductions in cocaine use may be a more viable treatment target compared to complete abstinence. However, few studies have examined the associated health benefits of this change. This study assessed how quality-of-life outcomes (psychological functioning, social functioning, sleep) change with reductions in cocaine-positive urine drug screens. Method: Participants (n = 107) with cocaine use disorder enrolled in a 12-week contingency management trial and were randomly assigned to highvalue, low-value, or noncontingent control groups. Quality of life was measured at predetermined intervals over the course of the trial. Linear mixed models disaggregated the proportion of cocaine-negative urine screens into between-subject (i.e., a participant’s average use across the trial) and within-subject (i.e., a participant’s deviation from their average) components to separately estimate their associations with quality-of-life outcomes. Results: Overall, higher proportions of cocaine-negative urine test results were associated with statistically significant, although modest, between- and within-subject changes in several quality-of-life measures, including psychosocial functioning, mental health, and sleep. Participants who reached at least 75% cocaine-negative urine test results during treatment demonstrated improvements in all Short Inventory of Problems–Cocaine outcomes, excluding Total Score. Conclusions: These findings indicate that reducing cocaine use improves quality-of-life outcomes in people with cocaine use disorder. These results also extend prior research on more robust health improvements that emerge when participants attain 75% negative urine test results over a trial. Future research should explore the extent to which these beneficial outcomes apply to other cocaine use disorder samples, including those with more severe comorbid psychosocial challenges at baseline.