At its most basic, narrative reviews are most useful for obtaining a broad perspective on a topic and are often more comparable to a textbook chapter including sections on the physiology and/or epidemiology of a topic. When reading and evaluating a narrative review, keep in mind that author's bias may or may not be present. The labels Narrative Review and Literature Review are often describing the same type of review. For scientific purposes, the term Literature Review is the one used most often. For more information on the Literature Review, click on that link under the Review By Type tab.
The difference between a Systematic Review and a Narrative Review can be summarized as follows:
| Good Quality Systematic Reviews | Traditional Narrative Reviews | |
| Review question formulation | Start with clear question to be answered or hypothesis to be tested. Specific: the populations, intervention, comparison, and outcome (PICO) of interest are specified. | May also start with a clear question to be answered, but they more often involve general discussion of a subject with no stated hypothesis; i.e., a topical approach. |
| Searching for relevant studies | Strive to locate all relevant published and unpublished studies, fully reported, to impact of publication and other biases. Comprehensive; high-recall search for published and unpublished material, fully reported, explicit search strategy; uses several evidence sources/databases. | Do not usually attempt to locate all relevant literature. Searches for pivotal papers known to the subject expert. Not usually specified, potentially biased. |
| Deciding which studies to include and exclude | Involve explicit description of what types of studies are to be included to limit selection bias on behalf of the reviewer; explicit inclusion and exclusion criteria for primary studies; tables reporting salient features of each article with expert synthesis, discussion and agreement by two or more reviewers. | Not usually specified, potentially biased; seldom reported |
| Assessing study quality | Methodology of the primary articles/studies is assessed; rigorous critical appraisal; meta-analysis resulting in a pooled estimate of intervention effectiveness (not done in all systematic reviews). | Seldom reported and if reported not usually systematic |
| Synthesizing study | Meta-analysis resulting in a pooled estimate of intervention effectiveness (not done in all systematic reviews). | Often a qualitative summary; may use meta-ethnographic techniques |