ABSTRACT

Mental health problems are highly prevalent in primary care. Validated tools to detect mental disorders in general practice are needed. The Four-Dimensional Symptom Questionnaire (4DSQ) was designed to help GPs differentiating between psychological distress and psychopathological conditions (depression, anxiety, somatization). The aim of the current study was to examine psychometric properties of the 4DSQ in a mental health setting. Reliability, factorial, construct, and criterion validity of the English translation of the 4DSQ were analyzed in an American sample of 159 patients attending a psychotherapy outpatient clinic. Measurement equivalence across languages was determined by analyzing differential item functioning (DIF) and differential test functioning (DTF) in the American sample and a Dutch mental health sample, matched by age and sex. A confirmatory factor analysis confirmed all 4DSQ subscales to be unidimensional. All 4DSQ subscales revealed excellent reliability (Cronbach’s alpha and McDonald omega ≥.90) and high correlations with a symptom distress subscale of an instrument that is commonly used to monitor psychotherapy progress, the Outcome Questionnaire-45. Eight items were flagged with DIF. The Depression subscale was free of DIF. DTF analyses showed an impact of DIF on scale level for the lower cutoff score of the Distress scale. The 4DSQ Distress score was the best predictor of a mood disorder diagnosis and the Anxiety score outperformed other 4DSQ scales to predict an anxiety disorder. In conclusion, the 4DSQ demonstrates excellent reliability and validity in a mental health setting. Further research is needed to determine reliable cutoff values on 4DSQ subscales to predict psychiatric diagnoses.

摘要

心理健康问题在初级保健中非常普遍。需要经过验证的工具来检测一般实践中的精神障碍。四维症状问卷 (4DSQ) 旨在帮助全科医生区分心理困扰和心理病理状况（抑郁、焦虑、躯体化）。当前研究的目的是检查 4DSQ 在心理健康环境中的心理测量特性。4DSQ 英文翻译的可靠性、析因、结构和标准效度在一个包含 159 名参加心理治疗门诊的患者的美国样本中进行了分析。通过分析按年龄和性别匹配的美国样本和荷兰心理健康样本中的差异项目功能 (DIF) 和差异测试功能 (DTF) 来确定跨语言的测量等效性。验证性因素分析证实所有 4DSQ 分量表都是一维的。所有 4DSQ 分量表都显示出极好的可靠性（Cronbach's alpha 和 McDonald omega ≥.90），并且与常用于监测心理治疗进展的工具的症状困扰分量表（结果问卷 45）高度相关。八个项目被标记为 DIF。抑郁分量表没有 DIF。DTF 分析显示 DIF 对遇险量表的较低截止分数的量表水平的影响。4DSQ 困扰评分是情绪障碍诊断的最佳预测指标，而焦虑评分在预测焦虑障碍方面的表现优于其他 4DSQ 量表。总之，4DSQ 在心理健康环境中表现出出色的信度和效度。