Health-related quality of life in outpatients with substance use disorder: evolution over time and associated factors

Health-related quality of life (HRQoL) is an important element of patient care and clinical research. The aim of this study was to describe HRQoL changes and identify associated factors during a 6-month follow-up of outpatients starting care for alcohol or opioid dependence.

HRQoL was measured at baseline and 3 and 6 months later using the SF-12. Data on the patients' sociodemographics, clinical characteristics and levels of anxiety and depression were collected using the Hospital Anxiety and Depression Scale (HADS). Repeated-measures analyses were performed to assess factors associated with global HRQoL differences and the evolution of HRQoL indicated by both physical and mental scores (PCS and MCS, respectively).

The mean PCS and MCS scores were initially low at 45.4 (SD = 8.6) and 36.0 (SD = 10.9), respectively. The improvement in HRQoL was rapid in the first 3-month period and then slowed and remained stable over the subsequent 3-month period. Being employed (p = 0.012), having no comorbidities (p = 0.014) and having no depression (p = 0.004) were associated with significant differences in the average PCS scores at the 3 time points. Patients who had lower overall HRQoL MCS scores on average were those for whom a medication was initiated (p = 0.009), as was the case for patients with anxiety (p < 0.001) and depression (p < 0.001). Patients with depression at baseline were also those for whom a significantly greater increase in MCS score during the 6 months of follow-up was observed.

Our findings highlight the importance of screening early psychological distress and considering other factors associated with HRQoL changes in outpatients after the first 3-month period of treatment for substance use disorder.