Table 1.

Inclusion and exclusion criteria.^a

Criteria	Inclusion	Exclusion
Article type	Systematic review with a minimum search of 2 databases	All other study designs
Language	All languages	Reviews for which translation is unavailable
Publisher	Academic journals Government reports Medical organizations	Predatory journals (not indexed in PubMed or Directory of Open Access Journals) Conference abstracts
Primary study designs	Clinical trials (randomized or nonrandomized) Experimental studies Longitudinal cohort studies	Cross-sectional study data Surveys Case studies Qualitative studies Animal studies In vitro studies
Population	Adults who smoke cigarettes, adults who have quit smoking, and adults who have never smoked	Youth
Data	Changes in disease symptoms Clinical test measurements Self-reported health status	Passive or second-hand exposure Only 1 primary study from included study designs
Bias assessment of primary studies	Individual primary studies assessed with any method	No bias assessment of individual primary studies Inappropriate bias tool
Analysis-synthesis method	Meta-analysis Tabulation Narrative assessment	Solely summary of individual primary studies

^aStudies excluded at the full paper examination will be listed in an appendix and will note the reason for exclusion.