Table 2

Risk-of-bias rating per study.

Study	Confounding	Selection of participants	Classification of intervention	Deviation from intended intervention	Missing data	Measurement of outcomes	Selection of reported result	Overall risk of bias
Budzyn et al20	Critical	Critical	Moderate	Moderate	Critical	Serious	Serious	Critical
Jehn et al21	Critical	Serious	Moderate	Moderate	Critical	Serious	Serious	Critical
Nelson et al22	Critical	Critical	Moderate	Moderate	Critical	Serious	Serious	Critical
Cowger et al 23	Critical	Critical	Moderate	Moderate	Critical	Serious	Serious	Critical
Boutzoukas et al24	Critical	Critical	Critical	Moderate	Critical	Serious	Serious	Serious
Manny et al25	Critical	Moderate	Critical	Serious	Low	Moderate	Critical	Critical
Coma et al27	Serious	Serious	Moderate	Moderate	Serious	Moderate	Moderate	Moderate
Alonso et al28	Serious	Serious	Moderate	Moderate	Serious	Moderate	Moderate	Moderate
UK Department for Education, 202230	Critical	Moderate	Moderate	Serious	Critical	Serious	Serious	Moderate
Oster et al31	Critical	Critical	Moderate	Serious	Serious	Serious	Serious	Serious
Sasser et al32	Critical	Critical	Moderate	Moderate	Critical	Serious	Serious	Serious
Lessler et al33	Critical	Critical	Serious	Moderate	Critical	Serious	Serious	Serious
White et al34	Critical	Moderate	Critical	Moderate	Low	Moderate	Moderate	Critical
Gettings et al35	Serious	Critical	Moderate	Serious	Critical	Moderate	Moderate	Serious
Tennessee Department of Health and Census36	Critical	Serious	Moderate	Moderate	Critical	Serious	Serious	Serious
Cabrera37	Serious	Moderate	Moderate	Critical	Serious	Serious	Moderate	Serious
Sood et al38	Serious	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate
Juutinen et al39	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Low	Moderate
Ludvigsson41	Moderate	Moderate	Critical	Low	Low	Low	Low	Serious
Suryawijaya et al42	Critical	Moderate	Low	Critical	Low	Low	Low	Serious
Brandal et al43	Critical	Low	Critical	Low	Low	Low	Low	Serious
Lam-Hine et al44	Serious	Critical	Serious	Low	Low	Moderate	Low	Serious