Table 3.

Bivariate analyses of hospital characteristics on annual cost per patient and percent change in annual cost per patient

Variable a	Coefficient	Standard Error	P-value
	Annual cost per patient ($)
Large vs. small hospitals b	−2382	1313	0.031
PSC vs. non-PSC	−970	1400	0.479
Non-metro vs. metro	−181	1386	0.896
Sustaining phase vs. implementation phase	−1341	1385	0.266
Mean NIHSS Score	−1153	586	0.061
	% change in annual cost per patient c
10% increase in per-protocol enrollment	−7.1%	1.1%	0.000
10% increase in annual stroke volume	−5.1%	1.9%	0.016

NIHSS = National Institutes of Health Stroke Scale

^aWe ran a separate bivariate model for each predictor variable. Therefore, the coefficients represent bivariate associations between the predictor variable and the outcome

^bBased on the definition used in the COMPASS trial, large hospitals are defined as those with at least 400 annual stroke patients for PSC hospitals, and those with at least 165 annual stroke patients for non-PSC hospitals

^cEstimated using log-log bivariate regression