The Association between Periodontitis and Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

Table 3

Methodological quality of case-control studies included in the meta-analysis.

Study	Selection				Comparability	Outcomes			Total scores
	Case definition adequate	Representative-ness of the cases	Selection of controls	Definition of controls	Comparability based on design or analysis	Ascertainment of exposure	Same method of ascertainment for cases and controls	Nonresponse rate
Zervou et al. (2004) [24]	☆	☆		☆	☆	☆	☆	☆	7
Grössner et al. (2006) [14]	☆	☆	☆	☆	☆☆	☆	☆	☆	9
Brito et al. (2008) [11]	☆	☆		☆	☆☆	☆	☆	☆	8
Rikardsson et al. (2009) [23]	☆	☆	☆	☆	☆		☆		6
Habashneh et al. (2012) [12]	☆	☆		☆	☆☆	☆	☆		7
Zhang et al. (2020) [25]	☆	☆		☆	☆☆	☆	☆	☆	8