Table 3.

Quality assessment results against the effective public health practice project quality assessment tool for human observational studies.

References	Selection bias	Design	Confounders	Blinding	Data collection method	Withdrawals/dropouts	Global ratings
Al Batanony et al. (15)	Moderate	Weak	Moderate	Moderate	Strong	Strong	Moderate
Cyprowski et al. (16)	Moderate	Weak	Moderate	Moderate	Strong	Strong	Moderate
Douwes et al. (17)	Moderate	Weak	Weak	Moderate	Strong	Strong	Weak
Heldal et al. (18)	Strong	Weak	Moderate	Strong	Strong	Strong	Moderate
Heldal et al. (19)	Strong	Weak	Strong	Strong	Strong	Strong	Moderate
Heldal et al. (20)	Strong	Moderate	Strong	Moderate	Strong	Strong	Strong
Lee et al. (21)	Strong	Weak	Strong	Strong	Strong	Moderate	Moderate
Melbostad et al. (22)	Moderate	Moderate	Weak	Strong	Strong	Strong	Moderate
Richardson (23)	Moderate	Weak	Moderate	Strong	Moderate	Moderate	Moderate
Rylander (24)	Strong	Weak	Strong	Strong	Strong	Strong	Moderate
Saad et al. (25)	Strong	Weak	Moderate	Strong	Strong	Strong	Moderate
Smit et al. (26)	Moderate	Weak	Strong	Strong	Strong	Strong	Moderate
Tabrizi et al. (27)	Moderate	Weak	Strong	Moderate	Strong	Strong	Moderate
Thorn (28)	Strong	Weak	Weak	Strong	Moderate	Strong	Weak
Tschopp et al. (29)	Moderate	Weak	Strong	Moderate	Strong	Strong	Moderate