Impact of statin therapy on postoperative outcomes following colorectal cancer surgery: A systematic review

Table 1 Quality assessment

Dimension	Selection
Ref.	Representative of the exposed cohort	Selection of the nonexposed control	Ascertainment of exposure	Outcome of interest not present at the start of the study
Löffler et al[16]	1	1	1	1
Bahl et al[15]	1	1	1	1
Pourlotfi et al[9]	1	1	1	1
Disbrow et al[10]	1	1	1	1
Fransgaard et al[11]	1	1	1	1
	Comparability; comparability of cohorts; control of important and additional factors
Löffler et al[16]	2
Bahl et al[15]	1
Pourlotfi et al[9]	1
Disbrow et al[10]	1
Fransgaard et al[11]	1
Ref.	Assessments of outcomes	Sufficient follow up time for outcomes to occur	Adequacy of follow-up of cohorts
Löffler et al[16]	1	1	0
Bahl et al[15]	1	1	0
Pourlotfi et al[9]	1	1	1
Disbrow et al[10]	1	1	1
Fransgaard et al[11]	1	1	1
Ref.	Total
Löffler et al[16]	8
Bahl et al[15]	7
Pourlotfi et al[9]	8
Disbrow et al[10]	8
Fransgaard et al[11]	8