Table 2.

Comparison of qualities between small and large trials in meta-analyses in critical care medicine.

	No. of patients in component trials		P value
	Large trials (>100 per arm, n = 73)	Small trials (<100 per arm, n = 244)
Sequence generating			0.031
Adequate	29 (59%)	50 (41%)
Inadequate/unclear	20 (41%)	72 (59%)
Allocation concealment			<0.001
Adequate	56 (82%)	114 (51%)
Inadequate/unclear	12 (18%)	111 (49%)
Blinding			<0.001
Adequate	49 (67%)	99 (41%)
Inadequate/unclear	24 (33%)	145 (59%)
Incomplete follow-up data addressed			<0.001
Adequate	36 (86%)	56 (48%)
Inadequate/unclear	6 (14%)	61 (52%)
Intention to treat			<0.001
Yes	38 (83%)	79 (52%)
No/unclear	8 (17%)	72 (48%)
Sample size calculation			<0.001
Yes	29 (88%)	32 (44%)
No/unclear	4 (12%)	40 (56%)
Year of publication			<0.001
Before 2002	55 (75%)	127 (52%)
After 2002	18 (25%)	117 (48%)