Thombs Brett D, Fuss Samantha, Hudson Marie, Schieir Orit, Taillefer Suzanne S, Fogel Joshua, Ford Daniel E, Baron Murray
Sir Mortimer B. Davis Jewish General Hospital, Montreal, Quebec, Canada.
Arthritis Rheum. 2008 Mar 15;59(3):431-7. doi: 10.1002/art.23328.
Between 36% and 65% of patients with systemic sclerosis (SSc) report symptoms of depression above cutoff thresholds on self-report questionnaires. The objective of this study was to assess whether these high rates result from differential reporting of somatic symptoms related to the high physical burden of SSc.
Symptom profiles reported on the Center for Epidemiologic Studies Depression Scale (CES-D) were compared between a multicenter sample of 403 patients with SSc and a sample of respondents to an Internet depression survey, matched on total CES-D score, age, race/ethnicity, and sex. An exact nonparametric generalized Mantel-Haenszel procedure was used to identify differential item functioning between groups.
Patients with SSc reported significantly higher frequencies (moderate to large effect size; P < 0.01) on 4 CES-D somatic symptom items: bothered, appetite, effort, and sleep. Internet respondents had higher item scores on 2 items that assessed interpersonal difficulties (unfriendly, large effect size; P < 0.01; disliked, large effect size; P < 0.01) and on 2 items that assessed lack of positive effect (happy, moderate effect size; P = 0.01; enjoy, large effect size; P < 0.01). Adjustment of standard CES-D cutoff criteria for potential bias due to somatic symptom reporting resulted in a reduction of only 3.6% in the number of SSc patients with significant symptoms of depression.
High rates of depressive symptoms in SSc are not due to bias related to the report of somatic symptoms. The pattern of differential item functioning between the SSc and Internet groups, however, suggests some qualitative differences in depressive symptom presentation.
在系统性硬化症（SSc）患者中，36%至65%的患者在自我报告问卷上显示出高于临界阈值的抑郁症状。本研究的目的是评估这些高比例是否源于与SSc高身体负担相关的躯体症状的差异报告。
比较了403例SSc患者的多中心样本与互联网抑郁调查受访者样本在流行病学研究中心抑郁量表（CES-D）上报告的症状概况，两组在CES-D总分、年龄、种族/族裔和性别上进行了匹配。采用精确非参数广义Mantel-Haenszel程序来识别组间的差异项目功能。
SSc患者在CES-D的4个躯体症状项目上报告的频率显著更高（效应量为中度至大；P < 0.01）：困扰、食欲、精力和睡眠。互联网受访者在评估人际困难的2个项目上得分更高（不友好，效应量为大；P < 0.01；被讨厌，效应量为大；P < 0.01），以及在评估缺乏积极影响的2个项目上得分更高（快乐，效应量为中度；P = 0.01；享受，效应量为大；P < 0.01）。针对躯体症状报告导致的潜在偏差对标准CES-D临界标准进行调整后，有显著抑郁症状的SSc患者数量仅减少了3.6%。
SSc患者中抑郁症状的高比例并非由于躯体症状报告相关的偏差。然而，SSc组和互联网组之间差异项目功能的模式表明抑郁症状表现存在一些质性差异。
