Health-related quality of life of patients in opioid substitution treatment in Germany

Introduction: Health-related quality of life (HRQOL) is an important treatment outcome criterion in chronic diseases. While the fields of medicine and mental health have embraced HRQOL as a valuable source of information in treatment and research, the field of addiction is lagging behind in this respect. Research on HRQOL in drug users has only been emerging in the past 10 years and the systematic use of HRQOL measures in clinical practice is scarce. Opioid substitution treatment (OST), the standard treatment for opioid dependence, typically measures its quality and treatment success by means of objective parameters, such as mortality. With opioid dependence as a chronic, relapsing disease, a long-term approach to patient care is needed, focusing on improvements in treatment adherence and patient wellbeing. HRQOL lends itself as a useful tool in this respect, seen that it is a measure of subjective wellbeing and a predictor of remission and treatment adherence. As such, HRQOL could be used to monitor the patient and provide tailored support in treatment. While measures of HRQOL have been implemented in an increasing number of studies on opioid dependence, the objective was often to demonstrate the effectiveness of OST in improving patients' wellbeing upon entering treatment. Epidemiological data on the HRQOL of OST patients is limited, and lacking entirely for Germany. Such cross-sectional data is of interests, as it includes the large population of long-term OST patients, whose wellbeing is rarely captured in the literature. The aim is to examine the HRQOL of OST patients in Germany, and assess its relation to mental and physical health.

Method: This investigation is part of the study 'Epidemiology Of Hepatitis C Virus Infection Among Opioid Substituted Patients' (ECHO), an observational, longitudinal, multicentre study conducted in a representative sample of 2,500 opioid substituted outpatients in Germany. A random sample of 750 patients in OST will be selected and measures of HRQOL (SF-12), mental health (BSI-18), physical health (OTI Health Scale), and sociodemographics will be administered. Cross-sectional data will be assessed by means of bivariate analysis.

Discussion: The present study will provide unique insights into the HRQOL of a large, random sample of OST patients in Germany. Findings will elucidate the relationship between subjective HRQOL and objective measures of mental and physical health, and have implications for patient care and research.