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Table 2 PFT values of patients with pre-BPTs

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

Parameter BPT (+) BPT (−)
SP sign (+)
(N = 341)
SP sign (−)
(N = 5101)
P value SP sign (+)
(N = 1782)
SP sign (−)
(N = 6437)
P value
Age, years 37 (24, 52) 21 (8, 48) < .0001 39 (30, 51) 40 (30, 53) .173
Sex, n (%)    < .0001    < .0001
 Male 121 (35%) 2618 (51%)   714 (40%) 3162 (49%)  
 Female 220 (65%) 2483 (49%)   1068 (60%) 3275 (51%)  
BMI, kg/m2 22.3
(19.6, 24.9)
20.1
(16.0, 23.6)
< .0001 22.6
(20.4, 24.8)
22.6
(20.1, 25.0)
.337
Obesity, n (%)
(BMI ≥ 30 kg/m2)
13/341 (4%) 114/5101 (2%) .062 54/1782 (3%) 90/6437 (1%) < .0001
FVC % predicted, % 102.4
(94.9, 112.0)
98.8
(90.9, 107.3)
< .0001 103.0
(94.9, 112.0)
100.0
(91.0, 100.6)
< .0001
FEV1% predicted, % 97.5
(88.2, 105.8)
91.9
(82.1, 101.1)
< .0001 101.0
(93.4, 109.2)
97.0
(88.2, 106.0)
< .0001
FEV1/FVC ratio 0.80
(0.75, 0.84)
0.79
(0.72, 0.85)
.009 0.83
(0.79, 0.87)
0.81
(0.77, 0.86)
< .0001
PEF % predicted, % 95.5
(85.6, 105.5)
92.0
(81.4, 103.6)
< .0001 103.8
(93.0, 114.7)
103.6
(92.5, 115.2)
.824
FEF50% % predicted, % 74.6
(60.2, 88.7)
63.1
(49.0, 80.0)
< .0001 86.3
(71.8, 103.3)
79.0
(63.2, 95.6)
< .0001
FEF75% % predicted, % 55.8
(40.7, 71.0)
49.5
(35.6, 67.6)
< .0001 65.0
(50.7, 84.4)
62.0
(46.4, 82.1)
< .0001
MMEF % predicted, % 65.8
(52.6, 81.4)
59.2
(44.2, 76.8)
< .0001 77.5
(64.1, 92.4)
72.7
(57.5, 88.7)
< .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 BPT categories
  2. BMI, body mass index; 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