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Table 1 Characteristic parameters

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

Parameter SP sign
BPT (−)
(N = 1782)
BPT (+)
(N = 341)
P value BDT (−)
(N = 194)
BDT (+)
(N = 25)
P value
Pre-BDT or BPT, %       
 Vol A/FVC ratio 19.0
(16.1, 23.1)
19.6
(15.9, 23.2)
.468 17.5
(13.9, 21.8)
0.0
(0.0, 9.8)
< .0001
 Flow A/PEF ratio 90.6
(86.2, 93.8)
87.6
(83.6, 92.1)
< .0001 88.6
(82.5, 93.1)
0.0
(0.0, 78.0)
< .0001
 Vol B/FVC ratio 40.9
(32.5, 49.1)
37.6
(31.4, 44.5)
< .0001 30.2
(22.9, 36.8)
0.0
(0.0, 14.3)
< .0001
 Flow B/PEF ratio 73.7
(64.9, 81.3)
73.5
(67.8, 79.9)
.404 78.3
(69.6, 85.2)
0.0
(0.0, 71.1)
< .0001
 (Vol A − Vol B)/FVC ratio 19.9
(13.2, 28.4)
16.6
(11.0, 22.7)
< .0001 10.0
(6.3, 16.6)
0.0
(0.0, 3.3)
< .0001
 (Flow A − Flow B)/PEF ratio 15.9
(10.1, 22.3)
12.4
(8.3, 18.1)
< .0001 8.7
(5.5, 13.8)
0.0
(0.0, 3.7)
< .0001
Post-BDT or BPT, %       
 Vol A/FVC ratio 18.6
(15.2, 23.0)
0.0
(0.0, 10.2)
< .0001 17.5
(14.9, 22.1)
16.6
(14.9, 19.1)
.083
 Flow A/PEF ratio 90.3
(85.2, 94.1)
0.0
(0.0, 68.7)
< .0001 89.2
(83.8, 93.4)
88.0
(83.9, 93.3)
.498
 Vol B/FVC ratio 35.0
(26.6, 43.9)
0.0
(0.0, 15.6)
< .0001 33.8
(25.4, 40.3)
32.9
(25.2, 37.9)
.331
 Flow B/PEF ratio 76.5
(66.4, 84.2)
0.0
(0.0, 56.9)
< .0001 76.2
(68.2, 83.0)
73.5
(69.2, 80.0)
.258
 (Vol A − Vol B)/FVC ratio 14.1
(8.8, 22.4)
0.0
(0.0, 3.6)
< .0001 12.8
(8.5, 20.6)
15.8
(10.3, 20.2)
.226
 (Flow A − Flow B)/PEF ratio 11.7
(6.8, 18.2)
0.0
(0.0, 2.5)
< .0001 11.5
(7.0, 16.8)
13.2
(8.7, 19.0)
.181
  1. Data are presented as median values and quartiles unless otherwise noted. Statistical comparisons based on percent unless otherwise noted for characteristic parameters of small plateau sign specific values. P values < .05 were considered to represent a significant difference in prevalence between SP signs of the negative and positive BPT or BDT categories
  2. BPT, bronchoprovocation test; BDT, bronchodilator test; SP, small plateau; Vol, volume; FVC, forced vital capacity; PEF, peak expiratory flow