TABLE 2.

Performance test characteristics of the febrile respiratory illness (FRI) and influenza-like illness (ILI) infection screening tools in primary and secondary analysis groups

	Positive, n		Negative, n		% (95% CI)		Predictive value		Likelihood ratio, % (95% CI)
	True	False	True	False	Sensitivity	Specificity	Positive	Negative	Positive	Negative
Laboratory-confirmed influenza (n=200)
FRI	35	103	50	12	74.5 (60.5–84.8)	32.7 (25.8–40.5)	25.4	80.6	1.1 (0.92–1.36)	0.78 (0.45–1.32)
ILI*	34	73	63	11	75.6 (61.3–85.8)	46.3 (38.2–54.7)	31.8	85.1	1.4 (1.12–1.77)	0.53 (0.31–0.91)
Clinical diagnosis of influenza (n=391)
FRI	39	131	206	15	72.2 (59.1–82.3)	61.1 (55.8–66.1)	22.9	93.2	1.9 (1.50–2.30)	0.45 (0.29–0.70)
ILI*	38	87	229	14	73.1 (59.8–83.2)	72.4 (67.3–77.1)	30.4	94.2	2.7 (2.08–3.39)	0.37 (0.24–0.58)

^*Total numbers in the ILI groups were fewer because all participants with a FRI did not have an ILI screen completed