Is improved quality of life associated with alcohol and other drug treatment response? Findings from the Patient Pathways treatment outcome study

Introduction and Aims: While most international treatment outcomes studies examine changes in alcohol and other drug (AOD) use as a primary outcome, and some examine quality of life (QOL) as a secondary outcome, there are mixed findings regarding the association between these two outcomes. We aimed to test whether improved QOL is associated with whether an individual responds to AOD treatment (i.e. successfully reduces their substance use).
Design and Methods: This prospective, multi‐site treatment outcome study recruited 796 clients from 21 publicly‐funded specialist AOD services in Victoria and Western Australia in 2012‐13. We examined rates of successful treatment response (past‐month abstinence or a reliable reduction in the use of an individual’s primary drug of concern relative to baseline level) in 555 (70%) participants followed up 12 months after initiating a treatment episode. Quality of life was assessed at baseline and follow‐up using the World Health Organization Quality of Life (WHOQOL‐BREF) (physical, psychological, social and environmental) domains.
Results: Mixed effects linear regression analyses indicated that successful treatment response was associated with significantly greater improvements in QOL, relative to improvement in treatment non‐responders (all domains P <0.001). Despite this, paired t‐tests indicated that non‐responders still significantly improved their social (P=0.007) and environmental QOL score (P=0.033), but did not significantly improve their psychological (P=0.088) or physical QOL score (P=0.841).
Discussions and Conclusions: Engaging in AOD treatment is associated with some improvement in QOL, even amongst those who do not substantially reduce their AOD use. However these improvements are significantly larger and broader when people succeed in reducing their substance use.
Implications for Practice or Policy: While the direction of causality between these two outcomes is unclear, the findings suggest reduced AOD use may be a pre‐requisite for improved physical and psychological QOL, or that treatment must actively target these co‐morbidities (i.e. through integrated care) to facilitate reduced AOD use.