Same-day single-dose vs large-volume split-dose regimens of polyethylene glycol for bowel preparation: A systematic review and meta-analysis

Table 2 Subgroup analysis

Subgroup	Studies, n	SSD, n	SpDs, n	I2 , %	P value for heterogeneity	Pooled analysis (cat-RR/con-MD)	95%CI	P value
2 L SSD with adjuvant vs SpDs
Adequate bowel preparation (categorical)[11,12,22,23,25,27,28]	7	1172	1177	51	0.05	1.00	(0.95, 1.05)	0.99
BBPS score for right colon (continuous)[11,12,23-27]	7	1227	1232	41	0.12	0.00	(-0.05, 0.05)	0.93
OBPS score for right colon (continuous)[22]	1	50	51
2 L SSD without adjuvant vs SpDs
Adequate bowel preparation (categorical)[11,15,16,18,21]	5	932	938	90	< 0.00001	0.86	(0.72, 1.02)	0.07
BBPS score for right colon (continuous)[11,15]	2	611	610	0	1.00	0.00	(-0.07, 0.07)	1.00
OBPS score for right colon (continuous)[16,21]	2	262	261	89	0.003	0.26	(-0.20, 0.72)	0.26
4 L SSD without adjuvant vs SpDs
Adequate bowel preparation (categorical)[13,14,20]	3	364	375	0	0.66	0.99	(0.94, 1.05)	0.82
BBPS score for right colon (continuous)[14]	1	172	167
OBPS score for right colon (continuous)[19,20]	2	110	110	0	0.71	-0.06	(-0.30, 0.18)	0.62

SSD: Same-day single-dose; SpDs: Split-dose; BBPS: Boston bowel preparation scale; OBPS: Ottawa bowel preparation scale; cat-RR/con-MD: Categorical-relative risk ratio/continuous-mean differences; CI: Confidence interval.