Table 1 Definitions of test and performance characteristics
Gold standard | ||||
|---|---|---|---|---|
Yes | No | |||
Yes | X | Y | ||
No | Z | K | ||
Test/Performance Characteristic | Definition | Explanation | ||
Patient Classification, % | ||||
True-Positive | X / (No. of Patients) × 100% | |||
False-Positive | Y / (No. of Patients) × 100% | |||
True-Negative | K / (No. of Patients) × 100% | |||
False-Negative | Z / (No. of Patients) × 100% | |||
Sensitivity, % | X / (X+Z) × 100% | % of FN hospitalizations correctly identified by claims-based definition | ||
Specificity, % | K / (Y+K) × 100% | % of non-FN hospitalizations correctly identified by claims-based definition | ||
Positive Predictive Value (PPV), % | X / (X+Y) × 100% | % of hosp. identified as FN hosp. by claims-based definition that were true-positives | ||
Negative Predictive Value (NPV), % | K / (Z+K) × 100% | % of hosp. identified as non-FN hosp. by claims-based definition that were true-negatives | ||
Accuracy, % | (X+K) / (No. of Patients) × 100% | % of all hospitalizations that were true-positives and true-negatives | ||
Likelihood ratio positive (LR+) | [X/(X+Z)] / [1-K/(Y+K)] | Odds of hosp. being an FN hosp. when claims-based algorithm is positive | ||
Likelihood ratio negative (LR-) | [1-X/(X+Z)] / [K/(Y+K)] | Odds of hosp. being a non-FN hosp. when claims-based algorithm is negative | ||