Table 1. Summary of training and test datasets.

Datasets	Measures	IH	UPMC
Training	Encounters datesa	1/2008 to 5/2010	1/2008 to 5/2010
	# of encounters	47,504	41,189
	# of influenza encounters	1,858	915
	# of NI-ILI encounters	15,989	3,040
	# of other encounters	29,657	37,234
	# of clinical notes	60,344 (1.2 per encounter)	76,467 (1.9 per encounter)
	# of finding extracted by UPMC parser	877,377 (18 per encounter)	1,031,134 (25 per encounter)
	# of finding extracted by IH parser	934,414 (20 per encounter)	849,932 (21 per encounter)
Test	Encounters dates	6/2010 to 5/2011	6/2010 to 5/2011
	# of encounters	182,386	238,722
	# of influenza encounters	661	339
	# of NI-ILI encounters	5,722	1,567
	# of other encounters	176,003	236,816
	# of clinical notes	220,276 (1.2 per encounter)	480,059 (2 per encounter)
	# of findings extracted by UPMC parser	2,822,282 (15 per encounter)	6,305,782 (26 per encounter)
	# of findings extracted by IH parser	2,950,928 (16 per encounter)	5,361,241 (22 per encounter)

^aFor training purposes, we only used other encounters during the summer period from July 1, 2009 to August 31, 2009.