Table 1. Regression results.

Dependent Variable ↓	Simple regression on non-admitted ILI presentations	Longitudinal fixed-effects regression (within-hospital variation) on non-admitted ILI presentations	Simple regression on admitted ILI presentations	Longitudinal fixed-effects regression (within-hospital variation) on admitted ILI presentations
Average waiting time (mins)	0.245 [0.200, 0.290]	0.166 [-0.073, 0.405]	0.884 [0.738, 1.030]	1.194 [0.893, 1.494]
Did-not-wait patients	0.467 [0.450, 0.483]	0.154 [0.063,0.245]	1.401 [1.346, 1.457]	0.429 [0.262, 0.595]
Number of access blocked patients	0.643 [0.608, 0.678]	0.179 [0.072, 0.286]	3.336 [3.249, 3.423]	0.974 [0.765, 1.184]
Sample size	5,168

Coefficient estimates [with 95% confidence intervals] from simple linear regression and longitudinal fixed-effects regression models using hospital/day observations in period 16/04/2009 to 29/08/2009 of average waiting time, number of did-not-wait patients, and number of access-blocked patients, on non-admitted and admitted ILI presentations. Standard errors are adjusted for clustering at the hospital level.