眼动检测评估精神分裂症的可行性及其价值

Feasibility of eye movement examination for schizophrenia and its value

目的:探讨眼动检测对精神分裂症的诊断价值。方法:于2005-01/03选择在山东省精神卫生中心住院的115例精神分裂症患者作为精神分裂症组,同时选择本院职工51例作为正常对照组。应用DEM-2000眼动检测系统分别对调查对象做眼动检测,通过自动记录各组凝视点数目和反应探索评分,分别按凝视点数≤31、28、27、26,反映探索评分≤6,≤5作为阳性,分析各组阳性及阴性检出人数,分别计算敏感度、特异度、阳性预测值和阳性似然比。敏感度=病例组真阳性数÷病例组总数×100%,可衡量实验正确的识别患某病者的能力;特异度=非病例组的真阴性数÷非病例组总数×100%,可衡量试验正确的识别非病例的能力;阳性预测值=真阳性数÷总阳性数×100%,表示试验结果阳性者属于真病例的概率;阳性似然比为试验结果真阳性率与假阳性率之比,阳性预测值和阳性似然比是综合评价敏感度和特异度的指标。当阳性预测值达到70%,阳性似然比为2.06时,敏感度特异度均较理想。结果:所有调查对象测试结果全部进入结果分析。①精神分裂症组的凝视点数、反映探索评分两项指标均显著低于正常对照组(P<0.01)。②分别按凝视点数≤31、28、27、26,反映探索评分≤6,≤5作为阳性,计算敏感度、特异度、阳性预测值和阳性似然比可以看出,将本调查眼动检测分界值定为凝视点数≤27或反映探索评分≤5,其阳性预测值可达70%以上,阳性似然比2.06以上,其敏感度特异度均较理想。若大于此值,其敏感度升高、而特异度降低,假阳性率增高,误诊率将增加,若小于此值,敏感度降低、而特异度升高,漏诊率增高。结论:眼动检测能在一定程度上反映被检测者的精神状态,对诊断精神分裂症有一定的辅助价值。

AIM： To explore the diagnostic effect of eye movement examination on schizophrenia. METHODS： 115 schizophrenia patients, who were hospitalized at Shandong Provincial Mental Health Center from January to March 2005, were selected as schizophrenia group. Meanwhile, 51 employees of this hospital were enrolled as normal control group, Eye movement examination was done in investigational objects with DEM-2000 eye movement examination system, respectively. By the automatic recording of number of eye fixation （NEF） and responsive search score （RSS） in every group, number of positive or negative check-out people was analyzed, and sensitivity, specificity, positive predictive value and positive likelihood ratio were calculated, respectively, based on NEF at most 31, 28, 27 and 26 and RSS at most 6 and 5 as positive. Sensitivity was equal to true positive number in case group ÷ total number in the case group ×100%, which could recognize correctly ability of patients with a certain disease measured in the trial. Specificity was equal to true negative number in the non-case group ÷ total number in the non-case group ×100%, which could recognize correctly the ability of non-cases measured in the trial. Positive predictive value was equal to true positive number ÷ total positive number×100%, which showed that the probability of result of trial belonged to true cases. Positive likelihood ratio was equal to true positive rate/false positive rate in the trial resuit. The positive predictive value and positive likelihood ratio were the indexes to assess the sensitivity and specificity comprehensively. When the positive predictive value was 70% and the positive likelihood ratio was 2.06, both the sensitivity and specificity were fairly ideal. RESULTS： All the test results of the investigational subjects were involved in the result analysis. ①The NEF and RSS in the schizophrenia group were lower significantly than those in the normal control group （P 〈 0.01 ）. ②The NEF at most 31, 28, 27 and 26 and RSS at most 6 and 5 as positive, respectively, from the calculation of sensitivity, specificity, positive predictive value and positive likelihood ratio we could concluded that the cut-off value of eye movement examination was NEF ≤ 27 or RSS ≤5, positive predictive value above 70% and positive likelihood ratio over 2.06, and its sensitivity and specificity were both fairly ideal. If more than this value, its sensitivity would increase, the specificity would decrease, false positive rate would increase, and the misdiagnosis rate would increase; If less than this value, the sensitivity would decrease, the specificity would increase, and the rate of missed diagnosis would increase. CONCLUSION： The eye movement examination can reflect the mental status of quizzees to some extent, and has certainly assistant value on the diagnosis of schizophrenia.