Validation of the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) in French psychiatric and general populations

Highlights

• This paper reports validation of the French WEMWBS in general and psychiatric populations. WEWMBS was included in the report submitted to Mental Health Research Network (2010) who addressed consensus around the measures of general mental health outcomes and was deemed to be appropriate and relevant for assessing people with psychosis and mood disorder.

• Results showed that WEMWBS proved valid and reliable in a further European population, despite the limits of the study, such as its small, convenience, and non-representative samples. It highlighted the scale trans-cultural validity. It is also valid and reliable in patients with chronic remitted psychiatric disorder, such a schizophrenia. WEMWBS is sensitive to change following wellbeing promoting interventions in both psychiatric and non-patient populations.

• Caution must be paid to bias any attributed to the absence of a priori determination of the required sample sizes of the conclusions, such as acceptability of the instrument or its sensitivity to change. Furthermore, impaired insight and cognition in the assessed patients also imply to pay attention must be paid before applying WEMWBS for all patients. Nevertheless, such a validated well-being measure for patients with schizophrenia may enhance the understanding of consequences of this chronic illness in cognition and emotion, and social functioning as well as being useful in specific care interventions for which there is a great need.

Abstract

The Warwick-Edinburgh Mental Well-Being Scale (WEMWBS) has been validated in general population samples in many countries. Interest in using this measure in clinical populations is growing, particularly for tertiary prevention and mental health promotion. This paper reports validation of the French WEMWBS in healthy and chronic remitted schizophrenia populations.

The French WEMWBS was administered to 319 workers, 75 students and 121 patients. For non-patients, self-reported Trait- and State-Anxiety, Mindfulness, Positive and Negative Affect and the General Health Questionnaire were completed. For patients, the Positive and Negative Syndrome Scale, Clinical Global Impression Severity Scale, Birchwood Insight Scale, Social Adjustment Scale, and Global Assessment of Functioning scale were completed. Test-retest reliability and responsiveness to intervention was assessed at 6 months.

Whatever the sample, response frequencies showed normal distributions, and internal consistency was good (Cronbach's α). Scree plots of eigenvalues suggested a single factor in the samples. The one-dimensional solution yielded suboptimal fit indices. Construct validity was confirmed. Significant improvement in scores was observed before and after intervention. Test-retest variation was non-significant.

Impairment of insight and cognition in the assessed patients implies that attention must be paid before applying WEMWBS to all patients. Nevertheless, WEMWBS proved valid and reliable in a further European population, suggesting transcultural validity for both monitoring and evaluation of interventions in healthy as well as chronic remitted schizophrenia populations.

Introduction

Interest in the concept of well-being and its contribution to all aspects of human life is increasing. According to the World Health Organisation (WHO, 2004), the “foundation for well-being and effective functioning for both the individual and the community” is “positive mental health.” This term and the term “mental well-being” are now used interchangeably, and cover both affect and psychological functioning (WHO, 2001). Mental well-being allows “individuals to realize their abilities, cope with the normal stresses of life, work productively and fruitfully, and make a contribution to their community” (Ryan and Deci, 2001). It includes the capacity for mutually satisfying and enduring relationships (Tennant et al., 2007), and has major consequences for health and social outcomes (Ryan and Deci, 2001, Tennant et al., 2007). As such, it is of relevance to recovery and tertiary prevention in patients with psychiatric disorders.

Existing instruments in the field of mental health were developed mainly to detect and measure mental illness. Their value for monitoring mental well-being and evaluating interventions to promote positive mental health is limited because of ceiling effects in general population samples. Such measures may also interfere with interventions that focus on the positive (e.g. recovery, positive psychology, asset-based or solution-focused approaches), by giving the impression that the interest of providers is not primarily the promotion of well-being but rather the prevention of illness, together with its social and economic costs.

Within the context of these limitations, UK researchers developed an instrument, the Warwick-Edinburgh Mental Well-Being Scale (WEMWBS; Tennant et al., 2007; http://www2.warwick.ac.uk/fac/med/research/platform/wemwbs/). This instrument covers both affective constructs, including the experience of happiness, and constructs representing psychological functioning and self-realization (Keyes, 2007). Its development focused entirely on positive constructs, resulting in a scale in which all items were positive and which was short enough to be useful in population-level surveys. WEMWBS comprises 14 items relating to the previous two weeks, with responses on a 5-point scale (from “none of the time” to “all of the time”).

WEMWBS has been validated for use in the UK with general populations aged 13 and above, and found to have good properties (Tennant et al., 2007, Clarke et al., 2011, Lloyd and Devine, 2012, Maheswaran et al., 2012, Taggart et al., 2013). Scores showed a single underlying factor, interpreted as mental well-being, with adequate social desirability bias. WEMWBS and its short version (SWEMWBS) (Stewart-Brown et al., 2009) have been validated in a wide range of languages and populations including Spanish (Castellvi et al., 2014), Italian (Gremigni and Stewart-Brown, 2011), Brazilian Portuguese (Santos et al., 2015) and Chinese (Ng et al., 2014), and its sensitivity to change has been demonstrated in observational studies (Maheswaran et al., 2012). The scale is suitable for monitoring mental well-being in healthy populations as it shows few ceiling or floor effects.

Although the scale is popular with psychiatric patients and their carers (Crawford et al., 2011), and has been deemed appropriate and relevant for people with psychosis and mood disorders (Mental Health Research Net, 2010), it has not yet been validated in psychiatric populations. Given the value of tertiary prevention in psychiatry (the prevention of relapse) and the new evidence base focusing on well-being in people experiencing chronic mental illness (Keyes, 2007), it is important that WEMWBS is validated in psychiatric populations. Cognizance of debates about the influence of lack of insight (Cynthia et al., 2015) and cognition (Reininghaus and Priebe, 2012) on the validity of patient-reported outcome measures (PROMS) in psychiatric populations, particularly those with schizophrenia, should not mask the call (Reininghaus and Priebe, 2012) for better validation of patient-reported outcome measures in psychiatry, especially short measures like WEMWBS.

The aim of the present study is to contribute to the validation of WEMWBS in three ways: first by evaluating the psychometric properties of the French translation (WEMWBS) in two healthy population samples, second by evaluating the psychometric properties of WEMWBS in a population with chronic psychiatric disorder and third by evaluating whether the scale appears sensitive to change after interventions designed to promote mental well-being in both healthy and psychiatric populations.