Cholecystectomy and the risk of alimentary tract cancers: A systematic review

Table 4 Descriptive characteristics of studies on the association between cholecystectomy and gastric cancer

Ref.	Period of study	Study design	No. of cases	No. of controls	Exposure ascertainment	Outcome ascertainment	Follow-up (yr)	Effect estimate	Adjustments	Quality of publication
Sarli et al[27], 1986	1980-1984	Case control	157	157	Surgical and database	Pathology	NA	0.77 (0.09-6.40)	Age, gender	26
Ichimiya et al[26], 1986	1953-1984	Cohort	29	1238	Self report	Death registry	NA	0.92 (0.66-1.28)	Age, gender	33
Nogueira et al[21], 2014	1992-2005	Case-control	429/12925	2572/100000	Medicare database	Cancer registry	> 6	OR = 1.26 (1.13-1.40)	Age, gender, diabetes	49
Goldacre et al[22], 2005	1963-1999	Cohort	177/39254	1354/334813	NHS database	Cancer registry	NA	1.06 (0.88-1.26)	Age, gender, calendar year, residence	36
Fall et al[28], 2007	1970-1997	Cohort	854/251672	NA	National registry	Cancer registry	11.5	1.11 (1.04-1.19)	Age, gender, surgical procedure	42
Chen et al[29], 2014	2000-2010	Cohort	31/5850		National database	Cancer registry	10	1.81 (1.09-3.02)	Age, gender, comorbidities	53

NA: Not available.