<aside> 💡

Sensitivity = a / (a + c)

Specificity = d / (b + d)

</aside>

<aside> 💡

Positive Predictive Value (PPV) = a / (a + b)

Negative Predictive Value (NPV) = d / (c + d)

</aside>

<aside> 💡

Prevalence = (a + c) / (a + b + c + d)

</aside>

• “假阳”与“假阴”的意涵
• High Sensitivity的意涵
• Low Sensitivity的意涵
• High Specificity的意涵
• Low Specificity的意涵
• PPV与NPV的意涵

葬爱家族成员 【打⑦折の暧昧】 为您抄书

Source: Gordis Epidemiology (Celentano & Szklo)

So far we have discussed a test with only two possible results: positive or negative. But we often test for a continuous variable, such as blood pressure or blood glucose level, for which there is no obvious “positive” or “negative” result. A decision must therefore be made in establishing a cutoff level above which a test result is considered positive and below which a result is considered negative.

<aside> 🛄

A Case Study to Understand Sensitivity & Specificity (”Screen-It”)

</aside>