Evidence table of systematic review on calcium intake and adenoma recurrence

Author Year [UI]Weingarten, 2008 [18254022]
DesignRandomized controlled trials: Cochrane Library Issue 2, 2007, the Cochrane Colorectal Cancer Group (CCCG) specialized register, MEDLINE (1966 to July 2007), Cancerlit (1963 to April 2002), Embase (1980 to July 2007)
PopulationHealthy adults and studies of adults at higher risk of colon cancer due to family history, previous adenomatous polyps, or inflammatory bowel disease
Intervention (Exposure) and ComparatorCalcium (>1200 mg/d) vs. placebo
ResultsCalcium vs. placebo colorectal adenoma recurrence: OR 0.74, CI 0.58–0.95, P=0.02
CRC: OR 0.34, CI 0.05–2.15, P=0.20
at least one adverse event requiring discontinuation: OR 0.93, CI 0.42–2.05, P=0.80
CommentsBased only on two RCTs (1346 participants). Heterogeneity due to different dose of supplementation (one RCT supplemented with 1200 mg/d and the other RCT with 2000 mg/d). Analysis based on fixed effects model; however, considering there are only two studies, random effects model might have been more appropriate. Analysis on adverse events is based only on reported data of one out of the two RCTs (Barron 1999). Only participants with high risk due to previous adenomas were recruited in these two RCTs; therefore, applicability of the results can only be considered for high risk population. Insufficient evidence to recommend the general use of calcium supplements to prevent colorectal adenoma or colorectal cancer
A priori design?XStudy quality assessment performed?X
Two independent reviewers?XStudy quality appropriately used in analysis?X
Comprehensive literature search?XAppropriate statistical synthesis?X
All publication types and languages included?Publication bias assessed?
Included and excluded studies listed?XConflicts of interest stated?X
Study characteristics provided?X

From: Appendix D, Evaluation of existing systematic reviews and evidence tables of the qualified systematic reviews

Cover of Vitamin D and Calcium
Vitamin D and Calcium: A Systematic Review of Health Outcomes.
Evidence Reports/Technology Assessments, No. 183.
Chung M, Balk EM, Brendel M, et al.

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