预测值是根据患者诊断试验的结果来预测其患某病可能性的指标。阳性预测值是指试验结果阳性者中真正患此病者所占比例[a/(a+b)],阴性预测值是指试验结果阴性者中确实未患此病者所占比例[d/(c+d)]。一般来说,越是敏感的试验,阴性预测值越高,反之特异性越高的试验,阳性预测值越高。除此以外,预 The predictive value is based on the results of the patient’s diagnostic test to predict the likelihood of a disease. The positive predictive value is the true proportion of patients with positive test results [a / (a ​​+ b)]. The negative predictive value is the proportion of those patients who did not have the test negative [d / (c + d)]. In general, the more sensitive the test, the higher the negative predictive value, whereas the higher the specific test, the higher the positive predictive value. In addition, pre-