Perioperative respiratory muscle training improves respiratory muscle strength and physical activity of patients receiving lung surgery: A meta-analysis

Table 3 Subgroup analysis about primary outcomes

	No. of studies	Mean	95%CI	P value	I2 (%)	Pheterogeneity
MIP
Intervention time
Preoperative	1	12.33	-5.49, 5.49	> 0.999	-	-
Postoperative	2	12.33	3.55, 21.11	0.006	0.0	0.67
Training method
IMT	3	9.53	3.98, 15.08	< 0.001	44	0.17
EMT	1	9.00	-9.00, 27.00	0.33	-	0.13
RMT	3	6.97	-2.81, 16.74	0.16	64	-
MEP
Intervention time
Preoperative	1	27	18.67, 35.33	< 0.001	-	-
Postoperative	2	15.83	-1.80, 33.45	0.08	58	0.12
Training method
IMT	2	-3.49	-10.57, 3.60	0.33	0	0.65
EMT	1	1.70	-14.67 to 18.07	0.84	-	-
RMT	3	20.72	8.60, 32.84	< 0.001	60	0.08

MIP: Maximal inspiratory pressure; MEP: Maximal expiratory pressure; IMT: Inspiratory muscle training; EMT: Expiratory muscle training; RMT: Respiratory muscle training.