Supplementary Table 4. Quality assessment of each study using Modified Newcastle Ottawa Scale.

Study	Selection Bias				Exposure Bias		Comparability Bias	Outcome Bias
	Definition of population	Source population	Typical of average population	Sample size	How performance using hop test(s) was decided	Demonstrates outcome was not present at time of hop testing	Comparability of cohort on the bias of the design or analysis	Validity and reliability of outcomes	Assessment of outcome(s) of interest	Adequacy of follow up
Bodkin et al., 2022	Low	Low	Low	High	High	Low	Low	High	High	Low
Cristiani et al., 2022	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Cristiani et al., 2025	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Faleide et al., 2021	Low	Low	Low	High	Low	Low	Low	High	High	High
Figueroa et al., 2025	Low	Low	Low	Low	High	Low	High	Low	Low	Low
Fältström et al., 2023	Low	Low	High	High	Low	Low	High	Low	Low	Low
Girdwood et al., 2024	Low	Low	Low	High	Low	Low	Low	High	High	High
Grindem et al., 2016	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Ithurburn et al., 2019	Low	Low	Low	High	Low	Low	High	Low	Low	High
Jang et al., 2014	Low	Low	High	High	High	Low	High	High	High	High
Kew et al., 2022	Low	Low	Low	High	High	Low	High	High	High	Low
Kim et al., 2022	Low	Low	Low	High	High	Low	High	Low	Low	Low
King et al., 2021	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Kitaguchi et al., 2020	Low	Low	Low	Low	High	Low	Low	High	High	High
Kyritsis et al., 2016	Low	Low	Low	High	Low	Low	High	Low	Low	Low
Legnani et al., 2024	Low	Low	Low	Low	Low	Low	High	Low	Low	Low
Marigi et al., 2023	Low	Low	Low	High	Low	Low	High	Low	Low	High
Marty-Diloy et al., 2025	Low	Low	Low	High	Low	Low	High	High	High	Low
Moksnes et al., 2009	Low	Low	High	High	Low	Low	High	Low	Low	High
Müller et al., 2015	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Nawasreh et al., 2018	Low	Low	Low	High	High	Low	Low	Low	Low	High
Niederer et al., 2024	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Niederer et al., 2025	Low	Low	Low	High	High	Low	High	Low	Low	Low
Novaretti et al., 2018	Low	Low	Low	Low	High	Low	Low	Low	Low	High
Nyland et al., 2025	Low	Low	Low	High	Low	Low	High	High	High	Low
Ohji et al., 2024	Low	Low	Low	High	Low	High	Low	Low	Low	Low
Ohji et al., 2021a	Low	Low	Low	High	Low	High	Low	Low	Low	Low
Ohji et al., 2021b	Low	Low	Low	High	Low	High	High	Low	Low	Low
Paterno et al., 2022	Low	Low	Low	High	High	Low	Low	Low	Low	Low
Paterno et al., 2025	Low	Low	Low	High	Low	Low	Low	Low	Low	Low
Piussi et al., 2023	Low	Low	Low	High	Low	Low	Low	High	High	High
Senorski et al., 2017	Low	Low	Low	High	Low	Low	High	Low	Low	High
Simonsson et al., 2024	Low	Low	Low	High	Low	Low	High	Low	Low	Low
Toole et al., 2017	Low	Low	Low	High	Low	Low	High	Low	Low	Low
Ueda et al., 2022	Low	Low	Low	High	High	High	Low	High	High	High
van Melick et al., 2022	Low	Low	Low	High	Low	Low	High	High	High	High
Webster et al., 2017	Low	Low	Low	High	High	Low	High	High	High	Low
Webster et al., 2018	Low	Low	Low	High	High	Low	High	Low	Low	Low
Webster et al., 2019a	Low	Low	Low	High	High	Low	High	High	High	High
Webster et al., 2019b	Low	Low	Low	High	Low	Low	High	High	High	High
Webster et al., 2020	Low	Low	Low	High	High	Low	Low	Low	Low	Low
Welling et al., 2020	Low	Low	Low	High	Low	Low	High	High	High	High
Zsidai et al., 2026	Low	Low	Low	High	Low	Low	High	Low	Low	Low