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Table 3 PFT values of patients with pre-BDTs

From: Clinical analysis of the “small plateau” sign on the flow-volume curve followed by deep learning automated recognition

Parameter BDT (+) BDT (−)
SP sign (+)
(N = 25)
SP sign (−)
(N = 2904)
P value SP sign (+)
(N = 194)
SP sign (−)
(N = 5044)
P value
Age, years 35 (29, 57) 57.5 (45, 66) < .0001 55 (45, 63) 62 (52, 69) < .0001
Sex, n (%)    .014    < .0001
 Male 12 (48%) 2047 (70%)   105 (54%) 3554 (70%)  
 Female 13 (52%) 857 (30%)   89 (46%) 1490 (30%)  
BMI, kg/m2 22.5
(19.9, 24.2)
22.5
(19.8, 25)
.795 23.7
(21.4, 26.0)
22.2
(19.5, 24.8)
< .0001
Obesity, n (%)
(BMI ≥ 30 kg/m2)
0/25 (0%) 96 (3%) 1.000 7/194 (4%) 127 (3%) .347
FVC % predicted, % 92.8
(82.9, 100.5)
78.1
(65.1, 91.0)
< .0001 101.1
(88.5, 112.5)
80.0
(66.8, 94.4)
< .0001
FEV1% predicted, % 72.1
(63.9, 78.5)
51.0
(35.9, 64.6)
< .0001 88.4
(78.5, 97.0)
58.0
(40.0, 74.0)
< .0001
FEV1/FVC ratio 0.67
(0.62, 0.71)
0.52
(0.42, 0.63)
< .0001 0.73
(0.68, 0.77)
0.59
(0.44, 0.69)
< .0001
PEF % predicted, % 76.1
(69.5, 84.4)
52.6
(36.8, 69.4)
< .0001 90.9
(78.5, 102.7)
62.1
(42.0, 82.5)
< .0001
FEF50% % predicted, % 38.5
(27.0, 47.3)
18.0
(10.3, 30.2)
< .0001 52.9
(42.9, 67.1)
23.8
(11.9, 40.8)
< .0001
FEF75% % predicted, % 24.2
(18.5, 33.5)
15.5
(10.8, 23.0)
< .0001 31.3
(23.1, 43.0)
19.4
(12.6, 29.7)
< .0001
MMEF % predicted, % 30.9
(21.1, 40.6)
15.8
(9.7, 25.2)
< .0001 44.2
(34.4, 53.6)
20.5
(11.3, 34.9)
< .0001
  1. Data are presented as absolute numbers in case of frequencies, median values, and quartiles in case of continuous parameters. Statistical comparisons based on percent predicted (pp) unless otherwise noted for pulmonary function test (PFT) values. P values < .05 were considered to represent a significant difference in prevalence between SP signs of the negative and positive BDT categories
  2. PFT, pulmonary function test; BMI, body mass index; BDT, bronchodilator test; SP, small plateau; FVC, forced vital capacity; PEF, peak expiratory flow; FEV1, forced expiratory volume in 1 s; FEFx%, instantaneous forced expiratory flow when x% of the FVC has been expired; MMEF, maximal mid-expiratory flow