University of Würzburg, Department of Medical Psychology and Psychotherapy, Medical Sociology and Rehabilitation Sciences, Würzburg, Germany.
University of Würzburg, Department of Medical Psychology and Psychotherapy, Medical Sociology and Rehabilitation Sciences, Würzburg, Germany.
J Affect Disord. 2018 May;232:268-275. doi: 10.1016/j.jad.2018.02.037. Epub 2018 Feb 21.
Depression is a frequent comorbidity of COPD and leads to worse clinical COPD-outcomes. PHQ-9 and PHQ-2 are two widely used brief instruments to assess depression. However, psychometric properties in COPD patients are unknown. This study examines factorial validity, measurement invariance and composite reliability (CR) of PHQ-9/PHQ-2, respectively, and concordance between both tools.
This is a secondary analysis of N = 561 COPD patients who filled out the PHQ-9 at the begin (T0), the end (T1) and 3/6/9/12 (T2/T3/T4/T5) months after pulmonary inpatient rehabilitation. Structural equation modeling was used to examine factorial validity and measurement invariance between gender, GOLD disease severity groups and over time. Concordance was assessed using Cohen's Kappa, Yules Y, positive and negative agreement.
A one-factor model (with one freed residual covariance) showed best model fit. At least partial scalar invariance could be established. Concordance between both instruments was substantial. 31.7% (26.2%) COPD patients showed clinically relevant depression according to PHQ-9 (PHQ-2) at T0. At T0-T2, PHQ-9 classified more patients as depressed than did PHQ-2. According to both measures, depression rates declined after rehabilitation. Reliability was high for both PHQ-9 (CR = 0.94) and PHQ-2 (CR = 0.89).
No gold-standard (clinical interview) to assess depression was used. Therefore, diagnostic accuracy for PHQ-9/PHQ-2 remains unclear.
PHQ-9 and PHQ-2 fulfill important psychometric criteria (factorial validity, invariance, reliability) for measuring depression in COPD. The results support their use in clinical practice to assess severity of depression. Diagnostic accuracy to identify major/minor depression of both instruments should be examined in future studies.
抑郁症是 COPD 的常见合并症，会导致更差的 COPD 临床结局。PHQ-9 和 PHQ-2 是两种广泛用于评估抑郁症的简短工具。然而，其在 COPD 患者中的心理测量特性尚不清楚。本研究分别考察了 PHQ-9/PHQ-2 的因子有效性、测量不变性和综合可靠性（CR），并比较了这两种工具之间的一致性。
这是对 561 例 COPD 患者的二次分析，他们在肺内住院康复开始时（T0）、结束时（T1）以及 3/6/9/12 个月后（T2/T3/T4/T5）填写了 PHQ-9。结构方程模型用于检验性别、GOLD 疾病严重程度组之间以及随时间的因子有效性和测量不变性。使用 Cohen 的 Kappa、Yules Y、阳性和阴性一致性来评估一致性。
一个单因素模型（带有一个自由残差协方差）显示出最佳的模型拟合度。至少可以建立部分标量不变性。这两种工具之间的一致性很高。根据 PHQ-9（PHQ-2），31.7%（26.2%）的 COPD 患者在 T0 时表现出临床相关的抑郁。在 T0-T2 期间，PHQ-9 比 PHQ-2 诊断出更多的抑郁患者。根据这两种测量方法，康复后抑郁率均有所下降。PHQ-9（CR=0.94）和 PHQ-2（CR=0.89）的可靠性均很高。
没有使用金标准（临床访谈）来评估抑郁。因此，PHQ-9/PHQ-2 的诊断准确性尚不清楚。
PHQ-9 和 PHQ-2 满足 COPD 患者测量抑郁的重要心理测量标准（因子有效性、不变性、可靠性）。结果支持在临床实践中使用它们来评估抑郁的严重程度。在未来的研究中，应检查这两种仪器识别主要/次要抑郁的诊断准确性。
