School of Public Health and Tropical Medicine, Tulane University, New Orleans, USA.
Curr Med Res Opin. 2010 Jul;26(7):1685-90. doi: 10.1185/03007991003795808.
The association between RA and depression has been well documented but so far there is not much research at a national level and none using a quick classification system of RA. The purpose of this study is to further determine if this association varies by differing severity in functional status of RA patients.
This study involved a retrospective pooled cross-sectional analysis of the Household Component of Medical Expenditure Panel Survey (MEPS) for the years 2004-2006. Each year's medical conditions file was merged with the person-level consolidated file. A total of 289 individuals comprised the final adult sample of RA and related diseases. RA cases were classified into four classes of functional status according to the ACR classification criteria. Tendency towards depression was ascertained by Patient Health Questionnaire (PHQ-2) scores with scores greater than or equal to three classified as high tendency towards depression. Multivariate logistic regression with survey weights was done using SAS 9.1.
After controlling for other relevant factors, patients belonging to Class III RA were 5.92 times more likely and those belonging to Class II RA were 3.78 times more likely to have high tendency towards depression as compared to Class I RA patients. Older age groups (>or=68 years) and physical activity were other significant predictors but in a negative direction, whereas a co-morbidity index of two showed a significant positive association.
The study provides important evidence that in a nationally representative sample of US non-institutionalized civilians, there is a strong association of depression to RA and related diseases by functional severity. However, the findings should be interpreted with caution because the data does not offer any information on duration in relation to PHQ-2 scores, thus making it hard to deduce if tendency towards depression was present before the diagnosis of RA. Furthermore, disease-specific and data-specific validation of the Charlson comorbidity index has not been done which leaves the possibility of residual confounding.
类风湿关节炎（RA）与抑郁症之间的关联已得到充分证实，但到目前为止，在国家层面上的研究还不多，也没有使用 RA 的快速分类系统进行研究。本研究的目的是进一步确定这种关联是否因 RA 患者功能状态的不同严重程度而有所不同。
本研究涉及对 2004-2006 年医疗支出面板调查（MEPS）家庭部分进行的回顾性汇总横断面分析。每年的医疗状况文件与个人层面的综合文件合并。共有 289 人构成了 RA 和相关疾病的最终成人样本。根据 ACR 分类标准，RA 病例被分为四个功能状态类别。通过患者健康问卷（PHQ-2）评分来确定抑郁倾向，评分大于或等于 3 分被归类为有较高的抑郁倾向。使用 SAS 9.1 进行带有调查权重的多变量逻辑回归分析。
在控制了其他相关因素后，属于 III 级 RA 的患者发生高抑郁倾向的可能性是属于 I 级 RA 患者的 5.92 倍，属于 II 级 RA 的患者发生高抑郁倾向的可能性是属于 I 级 RA 患者的 3.78 倍。年龄较大（>或=68 岁）和身体活动是其他显著的预测因素，但呈负相关，而合并症指数为 2 则显示出显著的正相关。
本研究提供了重要证据，表明在具有全国代表性的美国非住院平民样本中，RA 和相关疾病的严重程度与抑郁之间存在很强的关联。然而，由于数据没有提供任何关于 PHQ-2 评分与发病时间的信息，因此很难推断出抑郁倾向是否在 RA 诊断之前就存在，因此，这些发现应谨慎解释。此外，尚未对 Charlson 合并症指数进行疾病特异性和数据特异性验证，这使得存在残留混杂的可能性。
