Evidence of past dental visits and incidence of head and neck cancers: a systematic review and meta-analysis

Table 4 Quality rating of the included studies according to Effective Public Health Practice Project’s Qualitative Assessment Tool for Quantitative Studies

Reference	Overall quality assessment	Selection bias	Study design	Confounders	Blinding	Data collection	Withdrawals and drop outs
Chen et al. [44]	Strong	1	2	1	2	1	1
Mazul et al. [34]	Strong	1	2	1	2	1	2
Hashim et al. [20]	Strong	1	2	1	2	1	2
Laprise et al. [45]	Strong	2	2	1	2	1	1
Friemel et al. [21]	Strong	2	2	1	2	1	2
Dholam and Chouksey [46]	Strong	1	2	2	2	1	2
Bertl et al. [31]	Moderate	2	3	2	2	2	2
Huang J et al. [47]	Strong	1	2	1	2	1	2
Tsai et al. [48]	Strong	2	2	1	2	1	2
Ahrens et al. [22]	Strong	2	2	1	2	1	2
Narayan et al. [49]	Weak	3	3	3	2	1	3
Moergal et al. [23]	Moderate	3	2	2	2	1	2
Eliot et al. [35]	Strong	1	2	1	1	1	2
Chang et al. [50]	Strong	2	2	1	2	1	2
Langevin et al. [4]	Strong	1	2	1	2	1	2
Frydrych et al. [53]	Moderate	3	2	2	2	2	2
Groome et al. [3]	Strong	2	1	1	2	2	2
Macfarlane et al. [24]	Strong	2	2	1	2	1	2
Johnson et al. [36]	Strong	1	2	1	2	1	2
Divaris et al. [18]	Strong	2	2	1	2	1	2
Watson et al. [1]	Moderate	3	2	2	2	2	2
Marques et al. [39]	Strong	2	2	1	2	1	2
Guha et al. [40]	Strong	2	2	1	2	1	2
Rosenquist et al. [56]	Strong	1	2	1	2	1	2
Guneri et al. [26]	Moderate	1	2	2	2	1	2
Lissowska et al. [27]	Strong	1	2	1	2	1	2
Gellrich et al. [32]	Weak	1	3	1	3	1	1
Balram et al. [52]	Strong	1	2	1	2	1	2
Garrote et al. [41]	Strong	1	2	1	2	1	1
Winn et al. [42]	Strong	1	2	1	2	1	2
Moreno-Lopez et al. [54]	Strong	2	2	1	2	1	2
Talamini et al. [28]	Strong	1	2	1	2	1	2
Bundgaard et al. [29]	Strong	1	2	1	2	1	1
Lockhart et al. [38]	Weak	3	3	2	2	2	2
Maier et al. [30]	Moderate	3	2	2	2	1	2
Marshall et al. [37]	Moderate	3	2	1	2	1	2
Zheng et al. [51]	Strong	1	2	1	2	1	1
Franco et al. [43]	Strong	1	2	1	2	1	2
Elwood et al. [2]	Strong	2	2	1	2	1	1

ISSN: 2046-4053