Validation of Patient Health Questionnaire- 9 and Pilot Study of its Diagnostic Properties in a Heterogeneous Lithuanian Speaking Population

Abstract

Abstract Background there is a high prevalence of depressive and anxiety disorders in the world, though the diagnosis is mostly insufficient. The Lithuanian-speaking population does not have a validated and open-access screening tool for depression. Due to appealing diagnostic superiority, universality within different populations, and open access the validation of Patient Health Questionnaire 9 (PHQ-9) is a must. Methods PHQ-9 was translated. Face, content, criterion-related, and construct validity checked by a group of psychiatrists. Two groups, clinical (N43) and non-clinical (N416), filled out the questionnaire. Reliability, internal consistency, parallel form variability, factor analysis, and diagnostic cut-off points were measured. Results PHQ-9 translation has confirmed psychometric validity as high reliability of the questionnaire was estimated with a Cronbach α of 0.858–0.877. Exploratory factor analysis indicated a one-factor structure. Questionnaire performed with great accuracy to distinguish the presence of illness in the clinical sample. Preliminary cut-off points were determined to be 8 with a sensitivity of 86.5%, specificity of 100.0% and accuracy of 89.1% across the psychiatric patient population. Conclusions The translated version of PHQ-9 is a reliable and suitable tool to screen for depressive symptoms.