. 2020 Nov;12(11):6701–6711. doi: 10.21037/jtd-20-1668

Table 3. Postoperative pulmonary function test values (mean ratio, with SD) in proportion to preoperative value in intervention groups.

Variable	Water bottle PEP group		IMT group		P value
Variable	1POP/preop^a	2POP/preop^b	1POP/preop	2POP/preop	P value
FVC	0.66 (0.39)	0.65 (0.14)	0.64 (0.17)	0.63 (0.15)	0.90
FEV1	0.69 (0.41)	0.65 (0.15)	0.67 (0.19)	0.67 (0.18)	0.86
PEF	0.66 (0.49)	0.63 (0.17)	0.64 (0.16)	0.67 (0.20)	0.74
PIF	0.57 (0.19)	0.65 (0.21)	0.63 (0.16)	0.67 (0.18)	0.68
FIVC	0.62 (0.21)	0.65 (0.11)	0.64 (0.12)	0.64 (0.15)	0.86
FIV	0.58 (0.17)	0.62 (0.12)	0.62 (0.13)	0.63 (0.16)	0.78

^a, 1POP/preop first postoperative value in proportion to pre-operative value. ^b, 2POP/preop second postoperative value in proportion to pre-operative value. PEP, positive expiratory physiotherapy; IMT, inspiratory muscle training; FVC, forced vital capacity; FEV1, forced expiratory volume during one second; PEF, peak expiratory flow; PIF, peak inspiratory flow; FIVC, forced inspiratory vital capacity; FIV, forced inspiratory volume.