ویژگی های روان سنجی از مقیاس های اختلال تغذیه استرلینگ با بیماران بولیمیا

Background The Stirling Eating Disorder Scales (SEDS) are described as a well-validated measure of anorexic and bulimic cognitions and behaviors. However, there is little published research that demonstrates or tests the psychometric properties of the SEDS. The aim of this study was to assess the internal consistency of the SEDS with a clinical population at a specialist eating disorders service. Method This study was a cross-sectional component of a larger study (evaluating cognitive behavioural group treatment for bulimia nervosa). At assessment at a specialist eating disorders service, the SEDS was administered to a clinical sample of women with a diagnosis of bulimia nervosa (N=40). Cronbach's alpha coefficients were used to determine the internal consistency of the scales. Results While the internal consistency of the overall SEDS was good, the existing SEDS subscales lacked internal consistency. Only one of the eight subscales (perceived external control) had an acceptable alpha (>.700). By removing up to three questionnaire items for each subscale that most impaired the alpha, only two further subscales were raised to an acceptable alpha. The sample's scores did not closely reflect the reported norms. Discussion More studies are needed to determine the clinical and psychometric validity of the SEDS. However, the present findings indicate that the preliminary psychometric findings do not generalize to other adult clinical populations. Therefore, caution should be used when interpreting the results of the SEDS when working with adults with eating disorders.

There are a number of psychometric tests available for the evaluation of eating psychopathology, each with its own strengths and limitations (e.g., Eating Disorder Examination, Fairburn & Cooper, 1993; Eating Disorders Inventory-2, Garner, 1991; Eating Attitudes Test, Garner & Garfinkel, 1979; Bulimic Investigatory Test, Edinburgh, Henderson & Freeman, 1987). The Stirling Eating Disorder Scales (SEDS; Williams & Power, 1995) were developed to respond to the limitations of those measures by addressing a range of anorexic and bulimic cognitions and behaviors, as well as related psychological variables (Williams et al., 1990, Williams et al., 1993 and Williams et al., 1994). Despite being relatively widely used in the UK for clinical purposes, to date, the SEDS has limited evidence of psychometric validity. It was originally standardised on a sample of 38 bulimics, 40 anorexics, and 76 controls (Williams & Power, 1995). While it is not possible to determine the groupings involved from the available reports, these authors reported high internal consistency for the individual scales (Cronbach's alpha=.73–.99). Split-half reliability and test–retest reliability were also high. Campbell, Lawrence, Serpell, Lask and Neiderman (2003) have also shown that the SEDS has good criterion and discriminant validity and high internal consistency among adolescents with eating disorders, although many participants had difficulties comprehending some of the items. However, it is not clear that the SEDS is psychometrically valid for use among individual diagnostic groups of eating-disordered patients. A number of steps are required in order to determine that validity among different groups. This paper reports on the internal consistency of the SEDS among a group of bulimia nervosa patients at assessment for treatment.