Table 3.

Validity and Accuracy Measurements of the Three Different Algorithms Based on Different Data Sources

	Algorithm
	1	2	3
Data source	Inpatient: ICD-9 codes Outpatient: ICD-9 codes and supporting free text	Inpatient: ICD-9 codes Outpatient: ICD-9 codes	Inpatient: ICD-9 codes
Sensitivity	85.4%	82.9%	70.7%
Specificity	95.0%	95.0%	96.9%
PPV	81.4%	81.0%	85.3%
NPV	96.2%	95.6%	92.8%

Abbreviations: PPV, positive predictive value; NPV, negative predictive value.