Appendix Table 6.

Risk Group Statistics for the Models Built Using the Clinician Data

Derivation groupValidation group
Flu/Total (%)LRIn Group (%)Flu/Total (%)LRIn Group (%)
LASSO score
 Low0/18 (0.0)0.010.33/9 (33.3)0.511.8
 Moderate19/67 (28.4)0.438.57/25 (28.0)0.432.9
 High69/89 (77.5)3.451.129/42 (69.0)2.155.3
Conditional inference tree (manual)
 Low0/0 (NA)NA0.00/0 (NA)NA0.0
 Moderate9/58 (15.5)0.233.38/24 (33.3)0.531.6
 High79/116 (68.1)2.166.731/52 (59.6)1.468.4
Naive Bayes classifier
 Low4/36 (11.1)0.120.71/9 (11.1)0.111.8
 Moderate3/14 (21.4)0.38.02/7 (28.6)0.49.2
 High81/124 (65.3)1.871.336/60 (60.0)1.478.9
  • Abbreviations: LASSO, Least Absolute Shrinkage and Selection Operator; LR, Stratum-specific likelihood ratio.

  • Notes: The models were trained using the derivation set of clinician-reported symptom data, and evaluated on both the derivation and validation sets separately. We obtained quantitative risk predictions for each individual from the models, and assigned individuals with a risk less than 10% to the low risk group, individuals with a risk between 10% and 50% to the moderate risk group, and individuals with a risk greater than 50% to the high risk group.