RESUMO
BACKGROUND: Depression is a major burden for the health-care system worldwide. It is important to use standardized and easily applicable tools for large-scale population screening to improve the early detection of depression. The PHQ-9 has been recommended as the best available screening and case-finding instrument based on its brevity and ability to inform the clinicians on both depression severity and diagnostic criteria. AIMS: To evaluate the reliability and the validity of the Tunisian version of the PHQ-9 in the general population in Tunisia; the Tunisian version of the Hospital anxiety depression scale (HAD) was used as the gold standard for major depression diagnosis. METHODS: We undertook a cross-sectional, descriptive and analytical study. A total of 134 participants were enrolled. The PHQ-9 was validated against the HAD reference standard. RESULTS: Test-Retest reliability was determined by intraclass correlation. This scale was stable over 2 weeks (ICC=0,97).The Tunisian version of the PHQ-9 has a 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. A cut-off score of 10 had a sensitivity of 86,2 and a specificity of 83,8. The VPP was 0,6 and the VPN was 0,9. The prevalence of depression in ours ample was 13,4%. There were no statistical difference in gender, education and age for the prevalence of depression. CONCLUSION: The Tunisan version of the PHQ-9 is a valid and reliable casefinding instrument for detecting depression.
