Table 2.

Risk of Bias in Included Studies.

Study	Representativeness of the cohort	Ascertainment of exposure	Demonstration that outcome of interest was not present at start of study	Assessment of outcome	Was follow-up long enough for outcomes to occur?	Adequacy of follow up of cohorts
Tsimberidou et al. 2006 [14]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Cwynarski et al. 2012 [31]	Unclear/High risk	Low risk	Low risk	Low risk	Low risk	Low risk
Rozovski et al. 2015 [30]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk
Kharfan-Dabaja et al. 2017 [29]	Low risk	Low risk	Low risk	Low risk	Low risk	Low risk