Table 2.

Retrospective and prospective evaluation results.

Model performance metric	Retrospective result	Prospective result
ED prevalence	10%	7%
Predicted risk level, proportion of patients classified as “high risk”	8%	10%
Sensitivity (sens) [aka: recall]	19% (95% CI: 19–20)	32% (95% CI: 18–48)
Specificity (spec)	93% (95% CI: 93–93)	92% (95% CI: 90–94)
PPV	26% (95% CI: 26–26)	22% (95% CI: 12–34)
NPV	91% (95% CI: 91–91)	95% (95% CI: 93–97)
OR of ED visit (high-risk vs. low-risk patients)	3.5 (95% CI: 3.4–3.5)	5.4 (95% CI: 2.6–11.0)

Prospective evaluation metrics are at the patient level and retrospective evaluation metrics are calculated at the encounter level.

ED emergency department, NPV negative predictive value, PPV positive predictive value.