Department of Biostatistics,University of Pittsburgh Graduate School of Public Health,Pittsburgh,PA,USA.
Department of Neurology,University of Pittsburgh School of Medicine,Pittsburgh,PA,USA.
Int Psychogeriatr. 2018 Oct;30(10):1435-1445. doi: 10.1017/S1041610217002666. Epub 2018 Jan 16.
ABSTRACTBackground:Evidence suggests that semantic interference may be a sensitive indicator of early dementia. We examined the utility of the Semantic Interference Test (SIT), a cognitive stress memory paradigm which taps proactive and retroactive semantic interference, for predicting progression from mild cognitive impairment (MCI) to dementia in both a clinical and a population-based sample.
Participants with MCI in the clinical (n = 184) and population-based (n = 435) samples were followed for up to four years. We employed receiver operating characteristic (ROC) methods to establish optimal thresholds for four different SIT indices. Threshold performance was compared in the two samples using logistic and Cox proportional hazard regression models.
Within four years, 42 (22.8%) MCI individuals in the clinical sample and 45 (10.3%) individuals in the population-based sample progressed to dementia. Overall classification accuracy of SIT thresholds ranged from 61.4% to 84.8%. Different subtests of the SIT had slightly different performance characteristics in the two samples. However, regression models showed that thresholds established in the clinical sample performed similarly in the population sample before and after adjusting for demographics and other baseline neuropsychological test scores.
Despite differences in demographic composition and progression rates, baseline SIT scores predicted progression from MCI to dementia similarly in both samples. Thresholds that best predicted progression were slightly below thresholds established for distinguishing between amnestic MCI and cognitively normal subjects in clinical practice. This confirms the utility of the SIT in both clinical and population-based samples and establishes thresholds most predictive of progression of individuals with MCI.
摘要
有证据表明语义干扰可能是早期痴呆的敏感指标。我们研究了语义干扰测试（SIT）的效用，这是一种认知应激记忆范式，可以探测前摄性和回溯性语义干扰，用于预测从轻度认知障碍（MCI）到痴呆在临床和人群样本中的进展。
在临床（n=184）和人群（n=435）样本中，患有 MCI 的参与者被随访长达四年。我们采用接收者操作特征（ROC）方法为四个不同的 SIT 指数确定最佳阈值。使用逻辑和 Cox 比例风险回归模型比较两个样本中的阈值性能。
在四年内，临床样本中 42 名（22.8%）MCI 患者和人群样本中 45 名（10.3%）患者进展为痴呆。SIT 阈值的总体分类准确性范围为 61.4%至 84.8%。SIT 的不同子测试在两个样本中的表现特征略有不同。然而，回归模型表明，在调整人口统计学和其他基线神经心理学测试分数后，在临床样本中建立的阈值在人群样本中表现相似。
尽管人口统计学构成和进展率存在差异，但基线 SIT 分数在两个样本中均能预测从 MCI 到痴呆的进展。最佳预测进展的阈值略低于临床实践中用于区分遗忘性 MCI 和认知正常受试者的阈值。这证实了 SIT 在临床和人群样本中的有效性，并确定了最能预测 MCI 患者进展的阈值。
