Table 3 Quality Appraisal Checklist—Quantitative Studies Reporting Correlations and Associations [14]

Population

 Source of population well described

 Eligible population representative of the source of population

 Participants represent eligible population

Selection/methods

 Selection bias minimized

 Reasonable variables selection

 Acceptably low contamination

 Confounding factors identified and controlled

Outcomes

 Outcome measures and procedures reliable

 Outcome measurements complete

 All important outcomes assessed

 Similar follow-up time in exposed and comparison groups

 Follow-up time meaningful

Analyses

 Study was sufficiently powered to detect an intervention (if any)

 Multiple explanatory variables considered in the analysis

 Analytical methods appropriate

 Precision of association given or calculable and meaningful

Summary

 Study results internally valid

 Findings are generalizable to the source population