Table 3. Down and Black quality assessment.

	Daniel (2020)	Mekki (2018)	Valenza (2018)	Bonnevie (2018)	Maddocks (2016)	Kucio (2016)	Tasdemir (2015)	Vieira (2014)	Sillen (2014)	Vivodtzev (2012)	Vivodtzev (2006)	Neder (2002)	Bourjeily- Habr (2002)
Hypotheses/aims/objectives clearly described	√	√	√	√	√	√	√	√	√	√	√	√	√
Main outcome measures clearly described	√	√	√	√	√	√	√	√	√	√	√	√	√
Characteristics of patients/subjects clearly described	×	√	√	√	√	√	√	√	×	√	√	√	√
Interventions of interest clearly described	√	√	√	√	√	√	√	√	√	√	√	√	√
Distribution of principal confounders in each group clearly described	×	√	√	√	√	×	√	√	√	√	×	√	×
Main findings clearly described	√	√	√	√	√	√	√	√	√	√	√	√	√
Estimates of random variability in the data provided	×	√	√	√	√	×	√	√	√	×	×	×	×
Important adverse events reported	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Characteristics of patients lost to follow-up described	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Actual probability values reported	√	√	√	√	√	√	√	√	√	√	√	√	√
Participants approached representative of entire population	√	√	√	√	√	√	√	√	√	√	√	√	√
Participants recruited representative of entire population	√	√	√	√	√	√	√	√	√	√	√	√	√
Staff, places, and facilities were patients treated representative of majority of population	√	√	√	√	√	√	√	√	√	√	√	√	√
Blinding of study subjects	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Blinding of assessors	×	√	√	N/S	×	N/S	N/S	N/S	×	N/S	N/S	N/S	N/S
Data based on data-dredging clearly stated	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Time period between the intervention and outcome the same for cases and controls	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Appropriate statistical tests used	√	√	√	√	√	√	√	√	√	√	√	√	√
Compliance to intervention reliable	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Main outcome measure reliable and valid	√	√	√	√	√	√	√	√	√	√	√	√	√
Intervention groups or case–controls recruited from same population	√	√	√	√	√	√	√	√	√	√	√	√	√
Intervention groups or case–controls recruited at the same time	√	√	√	√	√	√	√	√	√	√	√	√	√
Study subjects randomized to the interventions	×	√	√	N/S	×	×	×	×	×	×	N/S	×	×
Was concealed randomization to allocation undertaken	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Adequate adjustment made in the analysis of confounders	√	√	√	√	√	√	√	√	√	√	√	√	√
Patient losses accounted for	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A	N/A
Sufficiently powered cohort size	√	√	√	√	√	√	√	√	√	√	×	×	×

Abbreviations: N/A, not applicable; N/S, not stated.