Table 1.

Metrics to test the diagnostic accuracy of algorithms

Metric name	Numerator	Denominator	Interpretation
SCD genotype algorithm
Sensitivity	Number of patients correctly identified as sickle cell anemia by the algorithm	Number of patients with sickle cell anemia as determined by chart review/registry	Ability of algorithm to identify patients with sickle cell anemia among SCD patients
Specificity	Number of patients correctly identified as not having sickle cell anemia by the algorithm	Number of SCD patients who did not have sickle cell anemia as determined by the registry	Ability of algorithm to identify patients without sickle cell anemia among SCD patients
Positive predictive value	Number of patients correctly identified as having sickle cell anemia by the algorithm	Total number of patients identified as sickle cell anemia by the algorithm	Probability of the patient to truly have sickle cell anemia if identified by the algorithm
Negative predictive value	Number of patients correctly identified as not having sickle cell anemia by the algorithm	Total number of patients identified as not having sickle cell anemia by the algorithm	Probability of the patient to truly not have sickle cell anemia if identified as such by the algorithm
Pain encounters algorithm*
Sensitivity	Number of acute care encounters correctly identified as pain encounters	Number of acute care encounter for pain as determined by chart review of the sample	Ability of algorithm to identify acute care encounters for pain
Specificity	Number of acute care encounters correctly identified as encounter for reasons other than pain crises	Number of acute care encounter for reasons other than pain crises as determined by chart review of the sample	Ability of algorithm to identify acute care encounters for reasons other than pain

^*The diagnostic accuracy is based on random samples selected for each year.