Table 2.

Risk of bias in included studies of cohort studies

Study	Selection (sample population)	Selection (participation rate)	Performance bias (outcome assessment)	Performance bias (analytical methods to control for bias)	Other form of bias
Fatti et al. [45]	High	Low	Unclear	Low	High
Fatti et al. [46]	High	Low	Unclear	Low	High
Franke et al. [47]	High	Low	Unclear	Low	High
Grimsrud et al. [48]	High	Low	Low	Low	High
Grimwood et al. [49•]	High	Low	Unclear	Low	High
Johnston et al. [50]	High	Low	Unclear	Low	High
Kipp et al. [51]	High	Low	Low	Low	High
Luque-Fernandez et al. [27]	High	Low	Unclear	Low	High
Massavon et al. [52•]	High	Low	Low	Low	High
Kaihin et al. [53]	High	Low	Low	Low	High
Munoz et al. [54]	High	Low	Low	Low	High