Validation and calibration of the patient health questionnaire (PHQ 9) in Argentina
BackgroundThe Patient Health Questionnaire 9 (PHQ 9) is a brief tool to assess the presence and severity of depressive symptoms. This study aimed to validate and calibrate the PHQ 9 to determine appropriate cut off points for different degrees of severity of depression in Argentina.MethodsWe conducted a cross sectional study on an intentional sample of adult ambulatory care patients with different degrees of severity of depression. All patients who completed the PHQ 9 were further interviewed by a trained clinician with the Mini International Neuropsychiatric Interview (MINI) and the Beck Depression Inventory II (BDI II) Reliability and validity tests, including receiver operating curve analysis, were performed.ResultsOne hundred sixty nine patients were recruited with a mean age of 47.4 years (SD 14.8) of whom 102 were females (60.4% The local PHQ 9 had high internal consistency (Cronbach's alpha 0.87) and satisfactory convergent validity with the BDI II scale [Pearson's correlation 0.88 (p 0.01) For the diagnosis of Major Depressive Episode (MDE) according to the MINI, a PHQ 9 8 was the optimal cut off point found (sensitivity 88.2% specificity 86.6% PPV 90.91% The local version of PHQ 9 showed good ability to discriminate among depression severity categories according to the BDI II scale. The best cut off points were 6 8 for mild cases, 9 14 for moderate and 15 or more for severe depressive symptoms respectively.ConclusionsThe Argentine version of the PHQ 9 questionnaire has shown acceptable validity and reliability for both screening and severity assessment of depressive symptoms.
BMC Psychiatry