PROPIEDADES PSICOMéTRICAS DE LAS ESCALAS BAS-DEP Y EBAS-DEP EN ESPA？OL PARA EL TAMIZAJE DE DEPRESIóN EN UNA MUESTRA GERIáTRICA MULTISITIO EN COLOMBIA: UN ESTUDIO EXPLORATORIO

this study aimed atexploring the psychometric properties of the brief assessment scale for depression (bas-dep) and the even briefer assessment scale for depression (ebas-dep) scales as screening instruments in a sample of 104 elderly participants, 41 men and 63 women, residing in two colombian cities. the bas-dep included 21 items assessing depressive mood, worry, suicidal ideation and somatic complaints. meanwhile, the ebas-dep was derived by means of extracting 8 ítems of the bas-dep, and its performance was regarded as equivalent by the authors of the original study (allen, et al., 1994).reliability, validity,sensitivity and specificity were assessedand a receiver operating characteristics curve (roc) was obtained. rasch analyses of adjustment, difficulty, and performance were executed and an item map was obtained.the bas-dep showed an appropriate level of reliability (.82).nonetheless, such value was low for the ebas-dep (.56).low reliability of the ebas-dep could be explained in terms of its briefness.nevertheless, its performance in terms of sensitivity and specificity was appropriate. factor solutions derived from the analyses revealed that most of the items in the bas-dep and ebas-dep scales contributed in explaining the total variance.when the yesavage gds scale was used as an external criterion of validity, coefficients of sensitivity and specificity above .70 were obtained in addition to cut-off scores of 5/6 for the bas-dep and 2/3 for the ebas-dep.roc statistics showed that both scales are similarly efficient to detect depression in the sample.these findings are similar to those reported in studies conducted in australia, england, germany, and china. this study has been the first to assess the psychometric properties of the spanish versions of these scales.further independent studies will enrich the evidence base in favor of the usefulness and validity of these instruments.