Modeling and Syndromic Surveillance for Estimating Weather-Induced Heat-Related Illness

Table 4

Positive predictive value of chief complaint text strings associated with heat.

String	Counts in heat-related visits	Counts in nonheatrelated visits	PPV(%)
Sun	39	15	72.2
Exhaust	32	15	68.1
Heat	10	10	50.0
Burn	17	196	8.0
Headache	11	850	1.3
Nausea	9	1127	0.8
Faint	4	488	0.8
Vomit	17	2334	0.7
Syncope	19	4194	0.5
Fever	7	1553	0.4
Fatigue	4	981	0.4
Weak	13	5483	0.2
Dizz	13	5525	0.2
Lighthead	1	424	0.2