Table 3.

Critical appraisal of systematic reviews by condition of interest

AMSTAR criteria	No. of reviews that met specified AMSTAR criteria
	Bowel conditions (n = 42)	Appendicitis (n = 40)	Gallstone disease (n = 17)	Peptic ulcer disease (n = 4)	Anorectal soft tissue infection (n = 2)	Abdominal wall hernia (n = 1)
A priori design	28	29	15	2	2	0
Duplicate study selection and data extraction	32	32	14	3	2	0
Adequate literature search†	39	29	16	3	2	1
Inclusion not restricted by publication status	21	20	5	2	1	0
Included and excluded studies listed	15	12	10	1	0	0
Details of included studies provided	29	31	14	4	2	1
Scientific quality of included studies assessed†	31	29	14	2	2	0
Conclusions appropriate based on study quality†	30	27	14	2	2	0
Appropriate methods to combine study results†	26	35	9	4	2	0
Publication bias assessed	16	23	10	2	1	0
Conflict of interest included	8	10	1	4	0	0
Overall risk of bias rated low‡	22	20	11	2	2	0
No. of AMSTAR criteria met (of 11)*	6 (1–10)	7 (1–10)	8 (2–10)	6 (3–10)	10 (10–10)	2

^*Values are median (range).

^†Key AMSTAR criteria for assessment of overall risk of bias.

^‡Low risk was assigned to reviews that fulfilled all four key criteria (comprehensive literature search was performed; the scientific quality of the included studies was assessed; these quality assessments were then used appropriately in formulating review conclusions; and the methods used to combine the findings were appropriate).