TABLE 2.

Performance Characteristics of Various Cutoff When Applied to the Test Dataset

	Prediction Model Cutoff Probability (Points)
Characteristic	0.05 (140 Points)	0.1 (169 Points)	0.15 (186 Points)	0.2 (199 Points)	Age > 65	Diabetes
Sensitivity	0.85	0.59	0.39	0.25	0.51	0.42
Specificity	0.64	0.84	0.91	0.95	0.77	0.84
Positive predictive value	0.13	0.18	0.21	0.23	0.16	0.18
NPV	0.99	0.97	0.96	0.95	0.95	0.95
Proportion declared negative	0.61	0.81	0.89	0.94	0.83	0.86
Proportion declared positive	0.39	0.19	0.11	0.06	0.17	0.14
Proportion expected for ICU admission	0.006	0.024	0.036	0.047	0.042	0.043

NPV = negative predictive value.

The choice of cutoff partly depends on the resources available (i.e., what proportion needs to be declared negative). The proportion expected to experience severe illness is estimated as the proportion declared negative (e.g., not vaccinated) times the proportion expected to experience severe illness given declared negative (1-NPV). Making that choice would then dictate the points cutoff to be used for deciding whether a patient meets the cutoff. After the cutoff is chosen, Table 3 may be used for each patient.