Table 4

Peak cough flow and spirometry in the reclined position

PatientsControlsDifference (95% CI)p Value
N2730
Peak cough flow (L/min)Mean (SD)297 (133)380 (121)−83 (−153 to −14)0.019
Peak cough flow (% pred PEF)61.2 (32.6)86.3 (17.3)−25.1 (−38.8 to −11.4)<0.001
Volume inspired before cough (L)2.22 (0.83)3.41 (0.72)−1.19 (−1.72 to 0.67)<0.001
Volume inspired before cough (% pred VC)64.3 (19.5)94.6 (15.6)−30.1 (−42.2 to −18.5)<0.001
Vital capacity (L)2.75 (0.89)4.06 (1.24)−1.31 (−1.92 to −0.71)<0.001
Vital capacity (% predicted)79.1 (24.3)111.9 (17.3)−32.7 (−44.1 to −21.4)<0.001
Inspiratory capacity (L)2.47 (0.79)3.56 (1.01)−1.09 (−1.76 to −0.43)0.002
Inspiratory capacity (% pred)80.1 (19.5)101.0 (13.7)−20.8 (−33.3 to −8.4)0.002
  • All p values calculated using Student’s t-test.

  • PEF, peak expiratory flow; VC, slow vital capacity.