Efficacy and safety of early oral feeding in postoperative patients with upper gastrointestinal tumor: A systematic review and meta-analysis

Table 1 Outcomes of studies

Ref.	Year	Sample size, n		Time of gas passage (mean ± SD, h)		LOS (mean ± SD, d)		Cost of hospitalization (mean ± SD, CNY, × 1000)		Pneumonia, n		Anastomotic leakage, n
		EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF
Wang et al[15]	2017	38	42	73.5 ± 6.3	80.1 ± 8.7	8.2 ± 1.6	9.5 ± 1.7	57.2 ± 5.1	63.1 ± 4.3	5%6	7%6	0	4.8%6
Liu et al[12]	2011	30	32	2.15 ± 0.431	2.97 ± 0.521	NR	NR	NR	NR	1	3	0	0
Yang et al[18]	2013	25	25	78.8 ± 8.4	87.1 ± 11.3	7.81 ± 2.58	9.62 ± 1.91	29.6 ± 4.2	35.2 ± 3.8	NR	NR	0	0
Wang et al[14]	2017	60	60	67.6 ± 7.5	85.2 ± 8.5	6.5 ± 1.8	9.2 ± 2.6	NR	NR	2	6	2	3
Lin et al[13]	2018	47	53	2.83 ± 0.961	3.56 ± 0.991	11.91 ± 1.43	12.68 ± 1.42	3.56 ± 0.615	3.93 ± 0.755	2	10	1	2
Li et al[17]	2014	50	50	67.3 ± 7.9	84.6 ± 8.7	6.8 ± 1.9	9.3 ± 2.5	NR	NR	NR	NR	NR	NR
Yu et al[16]	2016	72	67	2.1 ± 1.21	3.3 ± 1.51	6.0 ± 1.8	7.7 ± 2.5	1.5 ± 0.55	1.6 ± 0.85	1	3	0	1
Li et al[12]	2015	200	200	67.3 ± 7.9	84.6 ± 8.7	6.8 ± 1.9	9.3 ± 2.5	NR	NR	NR	NR	NR	NR
Gao et al[10]	2019	101	97	2.05 ± 0.711	2.50 ± 0.911	NR	NR	NR	NR	NR	NR	1	1
Hur et al[20]	2011	28	26	1.9 ± 1.21	2.9 ± 0.81	7.2 ± 1.7	8.5 ± 2.9	7749 ± 12504	8415 ± 29454	1		0	1
Berkelmans et al[19]	2020	65	67	NR	NR	NR	NR	NR	NR	16	23	12	11
Sun et al[22]	2018	140	140	2 (2-3)1,2	3 (2-3)1,2	7 (7-8)2	10 (9-12)2	NR	NR	15	17	5	6
Mahmoodzadeh et al[23]	2015	54	55	3 (2-3)1,2	4 (3-4)1,2	6 (5.75-7)2	8 (7-9)2	NR	NR	NR	NR	2	1
Shimizu et al[21] (DG)	2018	70	84	2 (1-3)1,3	2 (1-6)1,3	10 (5-70)3	10 (5-31)3	NR	NR	0	2	5	2
Shimizu et al[21] (TG)		32	30	2 (1-4)1,3	3 (1-6)1,3	10 (7-16)3	12 (7-44)3	NR	NR	1	0	4	4
Mi et al[11]	2012	30	30	79.9 ± 9.5	86.6 ± 8.7	7.83 ± 2.23	9.57 ± 1.96	30.22 ± 3.22	34.6 ± 3.21	0	1	0	0

¹The value is in days.

²Medians (lower quartile - upper quartile).

³Median (range).

⁴The walue is in USD($).

⁵The value is in CNY(¥),×10000.

⁶Incidence rate.

DG: Distal gastrectomy; EOF: Early oral feeding; LOS: Length of postoperative hospital stay; NR: No report; TG: Total gastrectomy; TOF: Traditional oral feeding.

Table 2 Number of postoperative complications and immune function indicators (CD4 cell count and CD4/CD8 cell ratio)

Postoperative complications, n		CD4_PreO, (%), mean ± SD		CD4_POD1, (%), mean ± SD		CD4_POD7, (%), mean ± SD		CD4/CD8_PreO, mean ± SD		CD4/CD8_POD1, mean ± SD		CD4/CD8_POD7, mean ± SD
EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF	EOF	TOF
13%1	17%1	43 ± 4	43 ± 4	36 ± 3	34 ± 3	42 ± 4	36 ± 4	1.8 ± 0.2	1.7 ± 0.3	1.4 ± 0.3	1.5 ± 0.3	1.8 ± 0.2	1.4 ± 0.3
7	7	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
3	4	43.2 ± 3.7	43.6 ± 4.1	35.3 ± 5.3	35.8 ± 3.6	40.6 ± 5.1	35.2 ± 3.8	1.68 ± 0.22	1.66 ± 0.27	1.52 ± 0.33	1.51 ± 0.42	1.77 ± 0.27	1.56 ± 0.31
7	17	43.4 ± 3.5	43.1 ± 3.1	30.6 ± 2.5	30.9 ± 2.4	42.4 ± 2.8	34.7 ± 2.3	1.9 ± 0.3	1.9 ± 0.2	1.5 ± 0.4	1.6 ± 0.3	1.8 ± 0.3	1.6 ± 0.3
5	16	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
NR	NR	43.2 ± 3.7	42.9 ± 3.3	30.4 ± 2.7	30.7 ± 2.6	42.2 ± 3.0	34.5 ± 2.5	1.8 ± 0.3	1.7 ± 0.3	1.3 ± 0.4	1.4 ± 0.4	1.7 ± 0.3	1.4 ± 0.4
10	11	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
NR	NR	43.5 ± 3.8	43.5 ± 3.6	31.5 ± 2.8	30.5 ± 2.5	42.1 ± 3.6	34.4 ± 2.4	1.6 ± 0.4	1.8 ± 0.3	1.6 ± 0.6	1.4 ± 0.3	1.7 ± 0.3	1.4 ± 0.8
11	10	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
7	8	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
48	56	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
6	5	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
17	8	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
11	6	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR	NR
4	5	42.2 ± 3.5	42.5 ± 3.6	36.4 ± 3.1	35.7 ± 2.9	40.6 ± 3.9	34.8 ± 3.1	1.76 ± 0.21	1.75 ± 0.22	1.40 ± 0.31	1.62 ± 0.45	1.76 ± 0.28	1.46 ± 0.23

¹Incidence rate.

EOF: Early oral feeding; NR: No report; LOS: Length of postoperative hospital stay; POD: Postoperative day; PreO: Preoperative day; TOF: Traditional oral feeding.

Table 3 Main characteristics of the included studies

Ref.	Year	Country	Location of cancer	Sample size, n		Sex, male/female, n		Age in yr, mean ± SD, male/female		Outcomes
				EOF	TOF	EOF	TOF	EOF	TOF
Wang et al[15]	2017	China	Gastric	38	42	NR	NR	58 ± 101		①②③④⑤⑥⑦⑧
Liu et al[12]	2011	China	Gastric	30	32	12/18	19/13	56.34	57.54	①②④
Yang et al[18]	2013	China	Gastric	25	25	15/10	16/9	57.5 ± 13.7	56.8 ± 11.9	①④⑤⑥⑦⑧
Wang et al[14]	2017	China	Gastric	60	60	31/29	33/27	58.6 ± 7.8	54.2 ± 8.4	①②③④⑤⑦⑧
Lin et al[13]	2018	China	Gastric	47	53	NR	NR	52.2 ± 6.61		①②③④⑤⑥
Li et al[17]	2014	China	Gastric	50	50	26/24	28/22	60.8 ± 5.9	56.0 ± 7.6	④⑤⑦⑧
Yu et al[16]	2016	China	Gastric	72	67	57/15	49/18	57.8 ± 13.1	60.1 ± 11.8	①②③④⑤⑥
Li et al[12]	2015	China	Gastric	200	200	104/96	112/88	60.8 ± 5.9	56.0 ± 7.6	④⑤⑦⑧
Gao et al[10]	2019	China	Gastric	101	97	68/33	55/42	56.3 ± 10.2	53.9 ± 11.6	①②③④
Hur et al[20]	2011	South Korea	Gastric	28	26	20/8	21/5	NR (mean ± SD)		①②③④⑤⑥
Berkelmans et al[19]	2020	Netherlands Sweden	Esophageal	65	67	56/9	56/8	65 (59-70)2	65 (61-70)2	②③
Sun et al[22]	2018	China	Esophageal	140	140	92/48	103/37	62 (53-59)2	63 (58-69)2	①②③④⑤
Mahmoodzadeh et al[23]	2015	Iran	Both	54	55	29/25	29/26	64.2 ± 8.2	66.4 ± 7.7	①③④⑤
Shimizu et al[21] (DG)	2018	Japan	Gastric	70	84	36/34	54/30	64.5 (37-79)3	64 (25-79)3	①②③④⑤
Shimizu et al[21] (TG)				32	30	25/7	8/22	68.5 (48-78)3	68.5 (40-79)3
Mi et al[11]	2012	China	Gastric	30	30	15/15	12/18	57.2 ± 9.5	60.0 ± 10.3	①②③④⑤⑥⑦⑧

¹Total mean ± SD.

²Medians (lower quartile - upper quartile).

³Median (range).

⁴Total mean.

Outcomes: ①: Postoperative complications; ②: Pneumonia; ③: Anastomotic leakage; ④: Time of gas passage; ⑤: Length of postoperative hospital stay; ⑥: Cost of hospitalization; ⑦: CD4 cell count; ⑧: CD4/CD8 cell ratio. DG: Distal gastrectomy; EOF: Early oral feeding; NR: No report; TG: Total gastrectomy; TOF: Traditional oral feeding.

Table 4 Eliminated studies in sensitivity study of postoperative exhaust time

Ref.	Year	Sample size, n		Postoperative exhaust time in h, mean ± SD		Eliminate reason
		EOF	TOF	EOF	TOF
Wang et al[15]	2017	38	42	73.5 ± 6.3	80.1 ± 8.7	High risk of bias
Yang et al[18]	2013	25	25	78.8 ± 8.4	87.1 ± 11.3	High risk of bias
Mi et al[11]	2012	30	30	79.9 ± 9.5	86.6 ± 8.7	High risk of bias
Li et al[17]	2014	50	50	67.3 ± 7.9	84.6 ± 8.7	High risk of bias
Yu et al[16]	2016	72	67	2.1 ± 1.21	3.3 ± 1.51	No data as mean ± SD
Sun et al[22]	2018	140	140	2 (2-3)1,2	3 (2-3)1,2	No data as mean ± SD
Mahmoodzadeh et al[23]	2015	54	55	3 (2-3)1,2	4 (3-4)1,2	No data as mean ± SD
Shimizu et al[21] (DG)	2018	70	84	2 (1-3)1,3	2 (1-6)1,3	No data as mean ± SD
Shimizu et al[21] (TG)		32	30	2 (1-4)1,3	3 (1-6)1,3	No data as mean ± SD

¹The value is in days.

²Medians (lower quartile - upper quartile).

³Median (range).

DG: Distal gastrectomy; EOF: Early oral feeding; TG: Total gastrectomy; TOF: Traditional oral feeding.