Table 2. Effects of covariates on cerebral blood flow.

	Model A			Model B
	Regression coefficient	95% Confidence interval	P value	Regression coefficient	95% Confidence interval	P value
PETCO2 (kPa)	9.91%	6.24%, 13.72%	<0.001	13.10%	7.60%, 18.88%	<0.001
Gender (male)	−14.14%	17.95%, −10.15%	<0.001	−6.53%	−13.02%, 0.45%	0.066
Hct (%)	—	—	—	−1.29%	−1.98%, −0.60%	<0.001
Study day #2	−2.82%	−4.62%, −0.98%	0.003	−2.32%	−4.43%, −0.16%	0.035
Study day #3	0.71%	−4.27%, 5.96%	0.784	−1.49%	−6.73%, 4.05%	0.591
Measurement #2	2.42%	0.59%, 4.27%	0.009	2.78%	0.43%, 5.17%	0.020
Measurement #3	−0.27%	−2.36%, 1.87%	0.804	0.02%	−2.42%, 2.52%	0.989
Intercept (mL/100 g per minute)a	52.82	50.69, 55.03	—	50.74	47.68, 54.00	—

Abbreviations: CBF, cerebral blood flow; Hct, hematocrit; P_ETCO₂, end-tidal expiratory P_CO2.

All regression coefficients (except the intercept) are reported as % change in CBF per unit change in covariate.

^aBaseline CBF at study day #1 in males and at mean P_ETCO₂ and Hct.