Psychometric Comparison of the PHQ-9 and BDI-II for Measuring Response during Treatment of Depression

Abstract

The Patient Health Questionnaire-9 Item (PHQ-9) and Beck Depression Inventory-II (BDI-II) are frequently used measures of depression severity, but little is known about their relative psychometric properties. The authors assessed psychometric properties of both measures during treatment for depression. The PHQ-9 and BDI-II scores from 172 depressed participants in two randomized controlled trials of treatment for depression were assessed and combined. Tests of internal consistency (Cronbach's α), factor analyses, correlational analyses, estimates of clinically significant change, and effect sizes (Cohen's d) were calculated after treatment and follow-up. Both scales demonstrated adequate internal consistency at pre- and posttreatment (PHQ-9 α = .74 and .81; BDI-II α = .87 and .90, respectively). Factor analysis failed to confirm the one-factor model previously reported for the PHQ-9, but two factors evidenced good fit for the BDI-II. Both scales converged more with each other than with the Sheehan Disability Scale at pre- but not at posttreatment. Responsiveness to change of PHQ-9 and BDI-II was similar at both posttreatment and follow-up. The consistency of agreement on indices of clinical significance was fair to moderate, but the BDI-II categorised a greater proportion of participants with severe depression than the PHQ-9. The BDI-II and PHQ-9 demonstrated adequate reliability, convergent/discriminant validity, and similar responsiveness to change. Differences were found in how they categorised severity. Pending the results of further studies, the attributes of the PHQ-9, of being shorter and based on the diagnostic criteria for depression, may indicate an advantage over the BDI-II.

Recovery From Depressive Symptoms Over the Course of Physical Therapy: A Prospective Cohort Study of Individuals With Work-Related Orthopaedic Injuries and Symptoms of Depression

“…Previous research in the field of psychology has validated a cut score of greater than or equal to 14 to identify individuals with clinically meaningful levels of depressive symptoms. 6,28,52,53,61 The BDI has been shown to be a reliable and valid measure of depression in individuals with pain, 26 and has been commonly used in studies using samples of patients with back and/or neck pain. 8,18,24,62 Pain Catastrophizing The Pain Catastrophizing Scale (PCS) was used to measure participants' levels of pain catastrophizing.…”

Prevalence, Gender Differences and Associated Factors of Depression among Adults with Type 2 Diabetes, Jordan

“…According to the latest official information released in 2014, the public debt has exceeded 85% of the total GDP, inflation rate 5.9%, unemployment rate 1%, unemployment youth ages (15)(16)(17)(18)(19)(20)(21)(22)(23)(24) 29.3%, and below poverty-line population 14.2%. On the other hand, and according to a recent United Nations Development Program (UNDP) report regarding Socio-economic Inequality in Jordan in 2015, Jordan's levels of inequality are low as compared with other countries with similar GDP.…”

Prevalence of Depression and its Associated Factos in Adults with Diabetes Mellitus : A Cross - Sectional Study in a Teritary Care Centre

“…Most importantly, the use of PHQ-9 can serve in comparisons of depressive symptomatology on an international basis given its worldwide validation. [32,33] This study has some limitations. The study was conducted in a tertiary care hospital, so a possible selection bias cannot be excluded.…”