Patient Health Questionnaire – 9

Number of participants: 233 adolescent students aged 14 to18 years

Population:

• Race/Ethnicity — 100% Indian

Summary:

This article discusses the diagnostic accuracy, reliability, and validity of the Patient Health Questionnaire - 9 (PHQ-9) when pediatricians use it among Indian adolescents. Results indicate a total of 31 students (13.3%) had a form of depression on psychiatric interview. A PHQ-9 score of 5 was ideal for screening (sensitivity, 87.1%; specificity, 79.7%). In addition to good content validity, PHQ-9 had good 1-month test-retest reliability (r = .875) and internal consistency (Cronbach's a = .835). There was high convergent validity with the Beck Depression Inventory (r = .76; p = .001). The concordance rate between the PHQ-9 threshold score of 10 and the International Classification of Diseases, 10th Revision based diagnosis was good (Cohen's k = .62). The area under the receiver operating characteristic curve for PHQ-9 was .939.

Number of participants: 442 youth aged 13 to17 years

Summary:

The purpose of this study was to examine the performance characteristics and validity of the Patient Health Questionnaire-9 Item (PHQ-9) as a screening tool for depression among adolescents. The PHQ-9 was completed by youth who were enrolled in a large health care' delivery system and participated in a study on depression outcomes. Criterion validity and performance characteristics were assessed against an independent structured mental health interview (the Child Diagnostic Interview Schedule [DISC-IV]). Construct validity was tested by examining associations between the PHQ-9 and a self-report measure of functional impairment, as well as parental reports of child psychosocial impairment and internalizing symptoms. Results indicate A PHQ-9 score of 11 or more had a sensitivity of 89.5% and a specificity of 77.5% for detecting youth who met the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria for major depression on the DISC-IV. Receiver-operator-curve analysis revealed that the PHQ-9 had an area under the curve of 0.88 (95% confidence interval: 0.82–0.94), and the cut point of 11 was optimal for maximizing sensitivity without loss of specificity. Increasing PHQ-9 scores were significantly correlated with increasing levels of functional impairment, as well as parental report of internalizing symptoms and psychosocial problems.

Number of participants: 322 youth aged 13 to16 years

Population:

• Race/Ethnicity — 100% German

Summary:

This study examines the criterion validity of the Patient Health Questionnaire 9-item (PHQ-9) and 2-item (PHQ-2) version as a depression screening instrument for adolescents. Adolescents were recruited from pediatric hospitals. Criterion validity of the PHQ-9 and PHQ-2 was assessed against diagnoses of any depressive disorder provided by a structured diagnostic interview. Areas under the receiver operating characteristics curve (AUCs) and sensitivities and specificities at optimal cutoff points were computed for both versions of the PHQ. Besides the dimensional algorithm, a categorical algorithm was applied for the PHQ-9. Validity measures of both scoring procedures of the PHQ-9 as well as PHQ-2 were compared statistically. In addition, unaided clinical depression diagnoses by the attending pediatricians were evaluated. Results indicate the AUC of the PHQ-9 (93.2%) was significantly higher than that of the PHQ-2 (87.2%). At optimal cutoffs, there was no significant difference in sensitivity (PHQ-9: 90.0%, PHQ-2: 85.0%), but in specificity (PHQ-9: 86.5%, PHQ-2: 79.4%). Although the categorical algorithm of the PHQ-9 was most specific (94.7%), sensitivity was just above chance (52.5%). The unaided clinical diagnoses yielded a sensitivity of 12.5% and a specificity of 96.0%.

Number of participants: 403 adolescent aged 13 to18 years

Population:

• Race/Ethnicity — 77.2% white, 4.2% African-American, 12.4% Hispanic, 2.2% Asian or Pacific Islander, 1.5% Native American and 2.2% Other

Summary:

To investigate the validity of the Patient Health Questionnaire for Adolescents (PHQ-A, a modified version of the PHQ-9), a self-administered instrument that assesses anxiety, eating, mood, and substance use disorders among adolescent primary care patients. Adolescents completed the PHQ-A and the Medical Outcomes Study Short-Form General Health Survey (SF-20) during or shortly after a visit to a primary care clinic or a school nurse's office. A few days later, clinical psychologists who were blind to the results of the PHQ-A administered a semi-structured clinical interview to assess the same psychiatric disorders and to conduct a global assessment of functioning (GAF) among 403 patients. Diagnostic agreement coefficients were computed and analyses of covariance were conducted. Results support the diagnostic validity of the PHQ-A. The PHQ-A and the clinical interview produced similar estimates of the prevalence rates of anxiety, eating, mood, and substance use disorders. The PHQ-A demonstrated satisfactory sensitivity, specificity, diagnostic agreement, and overall diagnostic accuracy, compared with the clinical interview. Adolescents with PHQ-A diagnoses experienced significantly poorer mental and overall functioning, more physical pain, and poorer overall health compared with those without psychiatric disorders. These differences remained significant after patients' age, gender, ethnicity, and site were controlled statistically.