Bulimic Investigatory Test, Edinburgh (BITE). A validation study of the Italian version

To explore the psychometric properties of the Italian version of the Bulimic Investigatory Test, Edinburgh (BITE).

A general population sample of 995 subjects (621 females), a clinical sample of 388 eating disordered females and a clinical sample of 710 patients with obesity (575 females).

Internal consistency was satisfactory. The factor analysis confirmed that the Symptom Scale is mono-factorial. Patients with bulimia nervosa (BN) purging showed the highest scores and those with anorexia nervosa (AN) restricting type the lowest. Obese patients showed higher BITE scores than controls in both sexes (P<0.01) and those with binge eating disorder (BED) showed higher scores than the rest of the sample (P<0.05). In patients with obesity with the threshold of 10 the Symptom Scale had a sensitivity for BED of 93% and a specificity of 55%; with the threshold of 20, sensitivity and specificity were, respectively, 44% and 92%. Normative values for BITE total and sub-scale scores in clinical and non-clinical samples are reported.

The Italian version of BITE is psychometrically sound and it can be a useful screening tool. Our data suggest that Symptom Scale, with a threshold of 20, has a good sensitivity for BN, although it does not effectively discriminate patients with BN from those affected by other eating disorders with binge-eating (BED, AN bingeing-purging type).