Brassiere wearing and breast cancer risk: A systematic review and meta-analysis

Table 2 Study characteristics

Ref.	Design	Country	No. of participants		Source of participants		Age of participants		Years of residence of participants	Residential status of participants	Age-match between participants	Ratio of cases to controls	Diagnosis of breast cancer status
			Cases	Controls	Cases	Controls	Cases	Controls					Casescontc	Controls
Hsieh et al[3]	Case-control	Greece, United States, Wales, Brazil, Yugoslavia, Taiwan, Japan	2325	7008	Hospital	Same hospital as cases	Over 35 years old	Over 35 years old	Not reported	Yes	± 2 yr	1:3	Diagnosed in hospital	Not reported
Feng et al[20]	Case-control	China	262	262	Hospital	Same hospital as cases, relative/neighbor of index case	Not reported	Not reported	Not reported	Yes	± 5 yr	1:1	Diagnosed in hospital	Not reported
Lee et al[10]	Case-control	Taiwan	250	219	Out-patient clinic or cancer center	Same as cases	Mean: 47.2;	Mean: 46.4	Not reported	Yes	± 5 yr	1:1	Pathological examination	Mammogram
Zhu et al[9]	Case-control	China	246	246	Hospital	Same hospital as cases; relative/neighbor of index case	Mean: 50.4	Mean: 50.0	Not reported	Not reported	± 5 yr	1:1	Diagnosed in hospital	Not reported
Zhang et al[11]	Case-control	China	284	669	Hospital	Health check program	Over 35 years old	Over 35 years old	Not reported	Yes	Not reported	1:3	Pathological examination	Not reported
Chen[21]	Case-control	China	167	334	Hospital	Neighbor	Not reported	Not reported	Over 10 years	Yes	± 2 yr	1:2	Diagnosed in hospital	Not reported
Hu and Lin[16]	Case-control	China	95	95	Hospital	Same hospital as cases	Median: 48	Median: 48	Over 10 years	Yes	Not reported	1:1	Pathological examination	Not reported
Liu et al[15]	Case-control	China	365	365	Not reported	Randomly obtained from population	Mean: 46.4	Mean: 45.6	Over 10 years	Yes	± 3 yr	1:1	Pathological examination	Not reported
Yao et al[13]	Case-control	China	200	200	Hospital	Same hospital	Mean: 47.30	Mean: 45.88	Over 10 years	Yes	± 2 yr	1:1	Pathological examination	Not reported
Chen et al[19]	Case-control	United States	Ducta: 454 Lobular: 590	469	Cancer Surveillance System	Randomly obtained from population	Between 55-74	Between 55-74	Not reported	Yes	± 5 yr	1:1:1	Pathological examination and tumor tissue specimens	Not reported
Liu et al[14]	Case-control	China	208	416	Hospital	Coworker/neighbor	Mean: 50.1	Mean: 49.2	Over 5 years	Yes	± 5 yr	1:2	Pathological examination	Not reported
Shen et al[12]	Case-control	China	275	275	Hospital	Not reported	Mean: 45.6	Mean: 48.5	Not reported	Yes	Not reported	1:1	Pathological examination	Physical examination