Table 2.

Critical Appraisal Using NHLBI Quality Assessment Tool for Observational Cohort and Cross-sectional Studies

Author (year)	Research question stated	Study population defined	Inclusion/exclusion stated	Sample size justification	Timeframe sufficient	Exposure measures defined	Outcome measures clearly defined	Confounding variables measured and adjusted	Quality rating
Kirizuka et al. (1997)	No	Yes	Yes	No	Yes	Yes	Yes	Yes	Fair
Nishikawa et al. (2015)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Ohkouchi et al. (2013)	Yes	No	No	No	Yes	Yes	Yes	No	Fair
Sugisawa et al. (2017)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Anderson et al. (2009)	Yes	Yes	Yes	No	No	Yes	Yes	Yes	Good
Gotanda et al. (2015)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Hyre et al. (2007)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Lee et al. (2016)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Lurie et al. (2015)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Malik et al. (2018)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Sharma et al. (2008)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Delfino et al. (2009)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Mott et al. (2005)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Parthum et al. (2017)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Rappold et al. (2011)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Reid et al. (2016)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good
Tinling et al. (2016)	Yes	Yes	Yes	No	Yes	Yes	Yes	Yes	Good