Description
The Patient Health Questionnaire-9 (PHQ-9) is a popular self-administered screening tool used for identifying major depressive disorder, according to Kaggwa et al. (2022). The questionnaire consists of nine items corresponding to the nine diagnostic criteria for depression in DSM-IV (Kaggwa et al., 2022). Each item is rated on a 0 to 3 scale, with the total score ranging from 0 to 27 (Kaggwa et al., 2022). Greater severity of depression symptoms is suggested by higher scores on the PHQ-9.
Reliability and Validity
The PHQ-9 has been shown to have established reliability and validity in different populations and settings. Lamela et al. (2020) conducted a systematic review and found that the PHQ-9 has good internal consistency, test-retest reliability, and criterion validity in different cultures and languages, including the Portuguese population. Similarly, Urtasun et al. (2019) validated and calibrated the PHQ-9 in the Argentinean population and found high internal consistency and criterion validity.
The PHQ-9 has also been shown to be a reliable and valid tool for detecting depression in patients with infertility (Maroufizadeh et al., 2019). There is also a possibility of screening for major depression (Negeri et al., 2021). The latter study found that the PHQ-9 has high sensitivity and specificity in detecting more significant depression, with a cut-off score of 10 having the best balance between sensitivity and specificity.
Demographic Variables
The demographic portion of the PHQ-9 includes questions about the respondent’s census data regarding their social and economic information. These demographic variables have been shown to affect the prevalence and severity of depression symptoms (Lamela et al., 2020). Patients who score positively on the PHQ-9 should undergo further assessment and evaluation by a qualified healthcare provider (Lamela et al., 2020). It is essential to indicate, PHQ-9 is intended to be used as a screening tool rather than a means of providing an official diagnosis of depression.
References
Kaggwa, M. M., Najjuka, S. M., Ashaba, S., & Mamun, M. A. (2022). Psychometrics of the patient health questionnaire (phq-9) in Uganda: A systematic review. Frontiers in Psychiatry, 13. Web.
Lamela, D., Soreira, C. S. S., Matos, P. M., & Morais, A. I. (2020). Systematic review of the factor structure and measurement invariance of the patient health questionnaire-9 (PHQ-9) and validation of the Portuguese version in community settings. Journal of Affective Disorders, 276, 220–233. Web.
Maroufizadeh, S., Omani-Samani, R., Almasi-Hashiani, A., Amini, P., & Sepidarkish, M. (2019). The reliability and validity of the patient health questionnaire-9 (phq-9) and phq-2 in patients with infertility. Reproductive Health, 16(1). Web.
Negeri, Z., Levis, B., Ma, J., He, C., Krishnan, A., Wu, Y., Bhandari, P. M., Neupane, D., Brehaut, E., Benedetti, A., & Thombs, B. D. (2021). Accuracy of the patient health questionnaire-9 for screening to detect major depression: Updated systematic review and individual participant data meta-analysis. BMJ, n2183. Web.
Urtasun, M. M., Daray, F. M., Teti, G. L., Coppolillo, F., Herlax, G., Saba, G. H., Rubinstein, A., Araya, R., & Irazola, V. (2019). Validation and calibration of the patient health questionnaire (phq-9) in Argentina. BMC Psychiatry, 19(1). Web.