. Author manuscript; available in PMC: 2017 Jul 25.

Published in final edited form as: Pancreatology. 2017 Feb 28;17(3):419–430. doi: 10.1016/j.pan.2017.02.015

Table 1.

Description of study features used to formulate the level of evidence of grade of recommendation.

Grade of recommendation	Level of evidence	Type of study
A	1a	Systematic review of (homogenous) RCTs
A	1b	Individual RCTs (with narrow confidence intervals)
B	2a	Systematic review of (homogenous) cohort studies of “exposed” and “unexposed” subjects
	2b	Individual cohort study/low-quality RCTs
	3a	Systematic review of (homogenous) case-control studies
	3b	Individual case-control studies
C	4	Case series, low-quality cohort or case-control studies
D	5	Expert opinions based on non-systematic reviews of results or mechanistic studies

RCT, randomized controlled trial.