University of Iceland, Reykjavik, Iceland.
Reykjavík University, Iceland.
Assessment. 2024 Sep;31(6):1332-1355. doi: 10.1177/10731911231216961. Epub 2023 Dec 30.
Scores on the Patient Health Questionnaire-9 (PHQ-9) are frequently used to assess depression both in research and in clinical practice. The aim was to examine the validity of the PHQ-9 sum score by using Mokken scale analysis (Study I) and cognitive interviews (Study II) on the Icelandic version of PHQ-9. A primary care sample of 618 individuals was used in Study I. The results indicate that the PHQ-9 items are not close enough to perfectly unidimensional for their sum score to accurately order people on the depression severity dimension. In Study II, the sample consisted of 53 individuals, with 28 having a history of depression and 25 not. The findings reveal a number of issues concerning respondents' use of the PHQ-9. No systematic differences were found in the results of the two groups. The PHQ-9 sum score should thus be interpreted and used with great care. We provide scale revision recommendations to improve the quality of PHQ-9.
PHQ-9 量表得分常用于研究和临床实践中评估抑郁症状。本研究旨在通过莫肯量表分析（研究 I）和认知访谈（研究 II）对冰岛语版 PHQ-9 进行验证。研究 I 中使用了初级保健样本 618 人。结果表明，PHQ-9 项目之间的接近程度还不够，无法达到完全的单维性，因此其总分无法准确地对抑郁严重程度维度上的人进行排序。在研究 II 中，样本由 53 人组成，其中 28 人有抑郁病史，25 人没有。研究结果揭示了一些关于受访者使用 PHQ-9 的问题。两个组的结果没有发现系统差异。因此，PHQ-9 总分的解释和使用需要谨慎。我们提供了量表修订建议，以提高 PHQ-9 的质量。
