Table 1.

Comparison of Subjects With Three Expiratory Efforts ≥ 6 s Without EBEV and Subjects With Efforts < 6 s But With EBEV^*

Variables	Subjects, No.	Three Efforts ≥ 6 s and Without EBEV	Without Acceptable Efforts	p Value
% Predicted FVC	271	78.5 ± 17.9 (n = 227)	65.5 ± 17.4 (n = 44)	< 0.0001
% Predicted FEV1	271	75.1 ± 18.2 (n = 227)	68.8 ± 17.8 (n = 44)	0.0370
MIP, cm H2O	258	89.2 ± 33.3 (n = 216)	76.3 ± 32.4 (n = 42)	0.0215
MEP, cm H2O	135	96.9 ± 40.7 (n = 115)	75.3 ± 30.0 (n = 20)	0.0248
Expiratory efforts, No.	278	6.1 ± 2.9 (n = 230)	7.8 ± 3.8 (n = 48)	0.0053
% With > 8 efforts	278	17.4 (n = 40)	37.5 (n = 18)	0.0018

^*Subjects who could not produce three efforts ≥ 6 s without EBEV attempted more expiratory efforts and had a lower mean MIP, MEP, and percentage of predicted FVC and FEV₁. Percentage of predicted FVC and FEV₁ were calculated for 271 of 278 subjects. Two subjects with race other than white or African American were excluded, and one subject with SCI due to a birth injury was excluded because it was not possible to accurately assess stature. In four subjects, none of the expiratory efforts was technically acceptable, so it was not possible to report a value for FVC or FEV₁.