Table 3. Predictive model of the percentage of hospital days (ICU and non-ICU) during at >100% hospital occupancy, using 11-week pandemic period fall 2009 pandemic period data as baseline occupancy, in study of 34 PHIS hospitals, United States*.

ED IRI volume	ED IRI admission rate
	Fall 2009 pandemic period†	2003–04 seasonal influenza period‡	Hypothetical
Admission rate, %	5.4	14.0	30
Same as during fall 2009 pandemic period, median (IQR)†	A: 23.3 (0–42.9)	B: 37.6 (11.6–58.4)	C: 63.6 (23.4–83.1)
100% increase from pandemic period, median (IQR)	D: 64.9 (16.9–81.8)	E: 72.7 (24.6–81.8)	F: 85.7 (40.2–98.7)

*ICU, intensive care unit; PHIS, Pediatric Health Information System; ED, emergency department; IRI, influenza-related illness; MMWR, Morbidity and Mortality Weekly Report (Centers for Disease Control and Prevention, Atlanta, GA, USA). Letters correspond to scenarios shown in the Figure.
†MMWR reporting weeks 35–45 (September 5–November 20, 2009).
‡MMWR reporting weeks 44–53 (November 1, 2003–January 9, 2004).