Table 2.

Summary of critical appraisal process based on the Newcastle–Ottawa Scale in case–control studies.

Case–Control Studies
Author; Year	A.1	A.2	A.3	A.4	B.1	C.1	C.2	C.3
Fontham ET et al., 1988 [39]
Morrison MEW et al., 2019 [40]
Azeem K et al., 2016 [41]
Shen Y et al., 2016 [42]
Steinmetz KA et al., 1993 [44]
Correa P et al., 1985 [45]
Lin T et al., 2017 [68]
Ambrosone CB., 2004 [69]
Tarrazo-Antelo AM et al., 2014 [70]
Steinmetz KA et al., 1993 [71]
Garcıa-Lavandeira JA et al., 2022 [72]
Hansson LE et al., 1993 [73]
Hara M et al., 2003 [74]
Witte JS et al., 1996 [75]
Lin HJ et al., 1998 [76]
Evans RC et al., 2002 [77]
Mahfouz EM et al., 2014 [78]
Le Marchand L et al., 1997 [79]
Joseph MA., 2004 [80]
Castelao JE., 2004 [81]
Lin J et al., 2009 [82]
Tang L., 2008 [83]
Barbone F et al., 1993 [84]
Mettlin C et al., 1989 [85]
Goodman MT et al., 1992 [86]
Graham S et al., 1978 [87]
Graham S et al., 1981 [88]
Graham S et al., 1972 [89]
Miller AB et al., 1983 [90]
Freudenheim JL et al., 1990 [91]
Slattery ML et al., 2000 [92]
Lin HJ et al., 2002 [93]
Ron E et al., 1987 [94]

Color legend: Green: response marked in the tool as the most appropriate option, with a low risk of bias; Red: answer marked in the tool as the least appropriate option; Orange: answer marked as doubtful. Dimensions of case–control studies: A.1. Adequate case definition; A.2. Representativeness of the cases; A.3. Selection of controls; A.4. Definition of controls; B1. Comparability of cases and controls; C.1. Record of exposure (consumption of broccoli); C.2. Same method to record exposure in cases and controls; C.3. Nonrespondent rate.