Validation measures include:

Kappa - measures the level of agreement between two data sources, measured on a binary scale (e.g., Disease Present/Disease Absent).  The kappa statistic corrects for the possibility of agreement due to chance.

Sensitivity - the percentage of true positives an algorithm detects among all positive disease cases. Positive disease cases are survey respondents in the CCHS validation cohort who reported having the specified disease.

Specificity - the percentage of true negatives an algorithm detects among all the negative disease cases. Negative disease cases are survey respondents in the CCHS validation cohort who did not report having the specified disease.

Positive predictive value (PPV) - the percentage of individuals with a positive result for an algorithm among those who reported having the disease.

Negative predictive value (NPV) - the percentage of individuals with a negative result for an algorithm who did not report having the disease.