Quality of life among alcohol-dependent patients: How satisfactory are the available instruments? A systematic review

Abstract

Aim

The purpose of this systematic review was to compare quality-of-life instruments used as outcome measures in randomized clinical trials for alcohol-dependence treatment.

Methods

Randomized controlled clinical trials, indexed in the EMBASE, PubMed and PsycINFO databases since 1981, which aimed at improving the quality of life in alcohol-dependent patients and used as instrument to measure the quality of life, as specifically designated by the authors, were included.

Results

Of the 331 articles screened, 18 studies were included in the review. Eight different quality-of-life instruments were used as outcome measures. Twenty-seven life domains were explored. Between-scale heterogeneity was high. The scale most frequently used was the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36). Only 1 clinical trial demonstrated a significant difference between intervention groups at all endpoints, using the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q).

Conclusion

Because many different instruments were used, it is difficult to compare quality-of-life improvement between trials. The most frequently used instrument was a generic health status measure that may not be well suited as a quality-of-life measure for subjects with alcohol dependence. The construction and validation of a specific patient-reported outcome based on alcohol-dependent patients’ concerns would effectively contribute to the assessment of treatment efficacy.

Introduction

Therapeutic goals for alcohol dependence are no longer limited to complete abstinence (EMEA, 2010). The forthcoming fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (http://www.dsm5.org/ProposedRevision/Pages/SubstanceUseandAddictiveDisorders.aspx) introduces a diagnostic shift from the binary diagnostic criteria of alcohol dependence and alcohol abuse to a single continuum of alcohol use disorders and introduces a clear measure of severity to help tailor treatment goals. Accordingly, alcohol reduction strategies offer a clear opportunity to address patient heterogeneity and lower the treatment barrier by introducing patients to treatment who would otherwise not be treated.

The primary endpoints typically used in clinical trials are based on the quantity of alcohol consumed or counting the number or percentage of days of abstinence or excessive drinking (Allen, 2003). These criteria do not reflect the changes observed in more complex patients who do not have a linear course of their disease or who change their drinking patterns over time (Zywiak et al., 2011). Additionally, these criteria are not directly relevant to clinical practice; they have been shown to be the preferred criteria for success in clinical practice for only a quarter of alcohol treatment specialists (Luquiens et al., 2011). Alcohol use disorders are complex diseases affecting medical, psychological and social domains (Alcohol and Public Policy Group, 2010). How can we show that a therapeutic intervention benefits alcohol-dependent patients regarding this complexity? Many judgment criteria can be used, developed and combined (Cisler and Zweben, 1999, LoCastro et al., 2009), such as: general health, severity of dependence, cost of interventions, negative consequences related to consumption (Miller, 1995) and quality of life (QoL).

QoL describes patients’ feelings about domains of functioning that are important to them but that are not captured by traditional symptom assessments (Carr et al., 2001). Traditionally, two types of QoL assessment instruments are distinguished: Health-related QoL and general QoL instruments. Health-related QoL instruments explore patients’ perceptions of the impact of a particular disease on their lives. Classically, Health-related QoL involves four domains: (1) physical state, including autonomy and physical abilities; (2) physical well being, including pain and physical symptoms; (3) psychological state, including anxiety and depression; and (4) social relationships including the domains of family, friends and work (Leplège, 1999). General QoL instruments explore overall quality of life independently of any health condition. Their challenging purpose is to capture an overall state of well being, defined as the satisfaction of needs and desires common to most people (Leplège, 1999). This type of QoL instrument is thought to be less robust than health-related QoL instruments. QoL has been investigated in numerous studies in patients with alcohol dependence; however, there is no consensus on the definition of QoL (Zubaran and Foresti, 2009), especially within the field of alcohol use disorder treatment.

Therefore, the instruments used in these studies vary in structure and in the domains they explore. A previous review (Zubaran and Foresti, 2009) investigated QoL in a broader context of substance use. That review found only one instrument that was specifically validated for alcohol-dependent patients: the ALQoL-9, which was directly derived from the generic instrument SF-36. However, its development consisted in an item restriction from the SF-36 which captures the same information as the full-length version but with only nine items and that has been validated in an alcohol-dependent population.

In another review, the relationship between QoL and drinking behavior, alcohol use disorders and treatment outcomes were investigated (Donovan et al., 2005). That review supported the integration of QoL as an outcome measure in alcoholism treatment research. Because of the growing interest in this concept, many studies have been conducted since this review. Although QoL in patients with alcohol dependence may now be considered relevant, the reliability, content and sensitivity to change of the QoL measurements are still sensitive issues that lack data.

A working inventory of the data available in clinical trials seemed necessary before proposing a new specific instrument. Our article is a review of the clinical trials of alcohol-dependent patients that explicitly claim providing a QoL measure as defined by the authors. We decided to include trials even if their instruments were not initially conceived as QoL measures. Our purpose was to evaluate the current representation of QoL in the alcohol-dependent field, taking into account confusion of concepts. The purpose of this review is to identify the instruments used in clinical trials and to measure changes in QoL post intervention in alcohol-dependent patients. We focused our research on randomized clinical trials (RCTs) to be able to discuss the responsiveness of these measures. We describe the instruments and identify the domains we explored. Our intention was to clarify the concept of QoL as assessed in randomized control trials (RCTs) involving alcohol-dependent patients. Although a comparison of the trials was hindered by the variety of instruments used, we reported the QoL outcomes for each study. This review aimed to guide the choice of an instrument to assess QoL in alcohol-dependent patients and to suggest ways to build a useful, effective, alternative instrument to report changes in QoL experienced by alcohol-dependent patients during treatment.