Table 2.

Results of subgroup analysis.

Outcome of interest	No. of studies	No. of patients	OR/WMD	95% CI	P value	Heterogeneity P value	I 2%
Studies in Western countries
PF	12	1850	0.89	0.71-1.13	0.35	0.85	0
DGE	12	1850	0.56	0.43-0.73	<0.0001	0.43	1
Overall morbidity	12	1983	0.68	0.56-0.82	<0.0001	0.46	0
LOS	3	491	-3.30	-5.17, -1.44	0.0005	0.06	63
Readmission	12	1898	0.99	0.72-1.38	0.97	1.00	0
Reoperation	8	1457	0.92	0.63-1.34	0.67	0.86	0
Mortality	13	2059	0.95	0.56-1.61	0.84	0.99	0
Studies in Eastern countries
PF	6	1307	0.76	0.46-1.27	0.30	0.008	68
DGE	6	1307	0.44	0.32-0.62	<0.00001	0.77	0
Overall morbidity	6	1395	0.54	0.39-0.74	<0.00001	0.17	36
LOS	5	1194	-4.36	-4.93, -3.79	<0.00001	0.005	73
Readmission	6	1492	1.12	0.75-1.66	0.58	0.39	4
Reoperation	4	655	2.88	0.99-8.41	0.05	0.99	0
Mortality	7	1554	0.67	0.43-1.03	0.07	0.86	0
Case-control studies
PF	15	2848	0.85	0.70-1.04	0.11	0.38	7
DGE	15	2848	0.53	0.43-0.61	<0.0001	0.50	0
Overall morbidity	16	3057	0.62	0.52-0.73	<0.00001	0.31	13
LOS	6	891	-4.46	-5.08, -3.83	<0.00001	0.001	75
Readmission	14	2834	1.01	0.77-1.31	0.96	0.98	0
Reoperation	10	1706	0.96	0.66-1.38	0.82	0.89	0
Mortality	16	3057	0.77	0.55-1.07	0.12	0.99	0
RCT
PF	3	309	0.91	0.30-2.79	0.87	0.03	72
DGE	3	309	0.41	0.24-0.71	0.002	0.66	0
Overall morbidity	2	321	0.52	0.17-1.62	0.26	0.07	71
LOS	2	794	-3.71	-4.80, -2.62	<0.00001	0.83	0
Readmission	4	556	1.24	0.64-2.39	0.52	0.38	2
Reoperation	2	406	3.21	0.86-12.03	0.08	0.96	0

OR: odds ratio; WMD: weighted mean difference; CI: confidence interval; PF: pancreatic fistula; DGE: delayed gastric emptying; LOS: length of hospital stay.