Validation of the Tunisian version of the patient health questionnaire (PHQ-9)

Abstract

IntroductionThe PHQ-9 has been recommended as the best available screening and case-finding instrument for primary care based on its brevity, and ability to inform the clinicians on both depression severity and diagnostic criteria.ObjectiveOur study evaluated the reliability and the validity of the Tunisian version of the PHQ-9 in detecting major depression in general population.MethodWe undertook a cross-sectional and analytical study. A total of 134 participants, representative of the Tunisian general population, were enrolled. The PHQ-9 was validated against the HAD reference standard. The types of validity determined for the PHQ-9 in this study were: translation validity, internal reliability and criterion validity.ResultsTest-Retest reliability was determined by intraclass correlation. This scale is stable over 2 weeks (ICC = 0.97). The Tunisian version of the PHQ-9 was found to have good internal reliability (Cronbach's alpha = 0.84). As for criterion validity of the PHQ-9, the Pearson's correlation coefficient between the PHQ-9 and HAD was 0.94 and the Spearman's correlation coefficient was 0.81. This indicated a positive association of good strength between the two instruments. A cut-off score of 10 or higher on the PHQ-9 had a sensitivity of 86.2 and a specificity of 83.8. The VPP was 0.6 and the VPN was 0.9.ConclusionThe Tunisan version of the PHQ-9 has several potential advantages. It was found to be a valid and reliable casefinding instrument for detecting depression in general population.Disclosure of interestThe authors have not supplied their declaration of competing interest.