Table 1. Features of narrative and systematic reviews.

Narrative review	Systematic review
Flexible structure, format may vary across journals	Pre-defined strict structure
Often invited and written by subject experts	Subject experts as authors are desirable but not mandatory
Specialized training in searches through bibliographic databases and synthesizing evidence-based information is desirable for authors	Specialized training in meta-analyses is mandatory for authors
Search strategy is advisable	Search strategy is mandatory
Pre-registration of title is not required	Pre-registration of title is required (Cochrane/PROSPERO)
No pre-published protocol	Pre-published protocol is required
Broad scope, several citable points	Narrow scope, few citable points
Quality assessment of included studies is not required	Quality assessment/risk of bias analysis is mandatory
Quantitative synthesis of existing data is not required	Quantitative synthesis of data may be performed (meta-analysis)
Not considered as original articles	Some journals consider systematic reviews with meta-analyses as original research articles

PROSPERO = International Prospective Register of Systematic Reviews.