Accuracy of the 15-item Geriatric Depression Scale (GDS-15) in a community-dwelling oldest-old sample: the Pietà Study

Abstract Introduction Late-life depression (LLD) is common, but remains underdiagnosed. Validated screening tools for use with the oldest-old in clinical practice are still lacking, particularly in developing countries. Objectives To evaluate the accuracy of a screening tool for LLD in a community-dwelling oldest-old sample. Methods We evaluated 457 community-dwelling elderly subjects, aged ≥75 years and without dementia, with the Geriatric Depression Scale (GDS-15). Depression diagnosis was established according to DSM-IV criteria following a structured psychiatric interview with the Mini International Neuropsychiatric Interview (MINI). Results Fifty-two individuals (11.4%) were diagnosed with major depression. The area under the receiver operating characteristic (ROC) curve was 0.908 (p<0.001). Using a cut-off score of 5/6 (not depressed/depressed), 84 (18.4%) subjects were considered depressed by the GDS-15 (kappa coefficient = 53.8%, p<0.001). The 4/5 cut-off point achieved the best combination of sensitivity (86.5%) and specificity (82.7%) (Youden's index = 0.692), with robust negative (0.9802) and reasonable positive predictive values (0.3819). Conclusion GDS-15 showed good accuracy as a screening tool for major depression in this community-based sample of low-educated oldest-old individuals. Our findings support the use of the 4/5 cut-off score, which showed the best diagnostic capacity.

【摘要】晚年抑郁障碍（Late-life depression, LLD）虽属常见精神疾病，但仍普遍存在诊断不足的问题。当前临床实践中仍缺乏适用于75岁及以上高龄老年群体的经过验证的筛查工具，这一缺口在发展中国家尤为突出。
研究目的：评估某筛查工具在社区居住的高龄老年样本中针对晚年抑郁障碍的诊断准确性。
研究方法：本研究纳入457名社区居住的老年受试者，年龄≥75岁且无痴呆，采用老年抑郁量表（Geriatric Depression Scale, GDS-15）进行评估。抑郁诊断依据《精神障碍诊断与统计手册第四版》（DSM-IV）标准，通过迷你国际神经精神访谈（Mini International Neuropsychiatric Interview, MINI）开展结构化精神访谈后予以确定。
研究结果：共计52名受试者（11.4%）被确诊为重性抑郁障碍。受试者工作特征（Receiver Operating Characteristic, ROC）曲线下面积为0.908（p<0.001）。当以5/6作为截断阈值（非抑郁/抑郁划分标准）时，GDS-15筛查出84名（18.4%）抑郁受试者，Kappa系数为53.8%（p<0.001）。采用4/5截断阈值时，灵敏度（86.5%）与特异度（82.7%）达到最优组合，约登指数（Youden's index）为0.692，同时具备极佳的阴性预测值（0.9802）与合理的阳性预测值（0.3819）。
研究结论：在本次纳入的低学历社区居住高龄老年群体样本中，老年抑郁量表（GDS-15）作为重性抑郁障碍筛查工具展现出良好的诊断效能。本研究结果支持采用4/5截断阈值，该阈值具备最优的诊断能力。