TABLE 4

Subgroup Analysis of Host-Signature Assay’s Diagnostic Performance (for Patients With Suspicion of Acute Infection)

SubgroupNo. of Patients (Ref. Bacterial, Ref. Viral)Equivocal (%)Sensitivity (95% CI)Specificity (95% CI)
Age
 3 mo ≤ age < 3 y184 (30, 154)10.393.1 (83.2–100)91.9 (87.3–96.6)
 3 y ≤ age ≤ 5 y41 (12, 29)12.2100 (100–100)83.3 (67.3–99.4)
 5 y ≤ age ≤ 18 y82 (26, 56)14.691.7 (79.7–100)87.0 (76.8–97.1)
Time from symptom onset
 0 ≤ day < 268 (17, 51)5.993.3 (79.0–100)87.8 (78.2–97.3)
 2 ≤ day < 480 (17, 63)10.0100 (100–100)92.9 (85.9–99.8)
 4 ≤ day < 694 (18, 76)17.088.9 (72.8–100)86.7 (77.8–95.5)
 6 ≤ day ≤ 763 (16, 47)11.193.8 (80.4–100)92.5 (84.0–100)
Clinical syndrome
 CNS infection3 (0, 3)33.3N/A100 (100–100)
 FWS111 (8, 103)11.787.5 (57.9–100)87.8 (80.9–94.7)
 GE11 (1, 10)9.1100 (100–100)100 (100–100)
 LRTI47 (20, 27)8.595.0 (84.5–100)100 (100–100)
 URTI92 (17, 75)15.292.9 (77.4–100)84.4 (75.2–93.5)
 UTI16 (16, 0)093.8 (80.4–100)N/A
 Other21 (6, 15)4.8100 (100–100)100 (100–100)
Country
 Israel212 (32, 180)1693 (84–100)86 (80–92)
 Switzerland95 (36, 59)394 (86–100)100 (100–100)
  • Diagnostic performance was evaluated by comparing the reference standard outcome (according to the expert panel majority) with the host-signature assay outcome. The number of patients refers to the subgroup analyzed for diagnostic performance; that is, it does not include patients with indeterminate reference standard outcomes. The clinical syndrome was the diagnosis recorded by the attending clinician at discharge (and was not modified in light of data accrued after discharge) as described in the Table 1 legend. CNS, central nervous system and encephalitis; FWS, fever without source; GE, gastroenteritis; LRTI, lower respiratory infection; URTI, upper respiratory infection; UTI, urinary tract infection