Patients with inflammatory bowel disease and post-inflammatory polyps have an increased risk of colorectal neoplasia: A meta-analysis

Table 4 Assessing the overall quality of evidence supporting each outcome using Grading of Recommendations, Assessment, Development and Evaluation

Outcomes	Illustrative comparative risksa (95%CI)		Relative effect (95%CI)	No of Participants (studies)	Quality of the evidence(GRADE)
	Assumed risk	Corresponding risk
	NonPIPs	PIPs
Association of PIPs with colorectal neoplasia; Follow-up: 3.0-22.9 yr	Study populationb
	157 per 1000	273 per 1000(212 to 351)	RR 1.74 (1.35 to 2.24)	5424 (9 studies)	Low
Association of PIPs with advanced colorectal neoplasia; Follow-up: 3.0-22.9 yr	Study populationb
	102 per 1000	211 per 1000(151 to 293)	RR 2.07 (1.48 to 2.87)	3766 (6 studies)	Moderate due to large effect
Association of PIPs with colorectal cancer; Follow-up: 3.0-22.9 yr	Study populationb
	184 per 1000	356 per 1000(243 to 520)	RR 1.93 (1.32 to 2.82)	1938 (4 studies)	Low

^aThe basis for the assumed risk (e.g., the median control group risk across studies) is provided in footnotes. The corresponding risk (and its 95% confidence interval) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95%CI).

^bLabel: Moderate. GRADE Working Group grades of evidence: High quality: Further research is very unlikely to change our confidence in the estimate of effect; Moderate quality: Further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate; Low quality: Further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate; Very low quality: We are very uncertain about the estimate. CI: Confidence interval; RR: Risk ratio.