Table 1.

Characteristics and downs &black scores of studies included in the meta-analysis

Authors/Year	Country	Design	Assessment instruments	Sample size	Age	Type of stress	Specific events	Evaluation moment	Disease stage	Type of treatment	Result RR (95% CI)	Score
Chen 1995 [17]	England	Case–control	4 point scale (great, moderate, some, and little or no)	41/78	20 – 70	Great life events	None	No description	All stages	No description	7.08 (2.31-21.65)	18
Roberts 1996 [18]	America	Case–control	Holmes-Rahe life-event weights	258/614	50 - 79	Stressful life events	Allow for both shorter time of administration and appropriateness (primarily older women)	During the previous 5 years	All stages	Hormone replacement therapy	0.9 (0.78-1.05)	18
Protheroe 1999 [19]	Australia	Case–control	Four point scale, and six point scale for severity difficulties lasting 4 weeks	106/226	40 - 79	Stressful life events	Excluded events that were related to past and present breast problems, or a first degree relative's breast cancer	During the previous 5 years	All stages	Hormone replacement therapy	0.91 (0.47-1.81)	17
										Oral contraceptives
Kruk 2012 [20]	Poland	Case–control	Holmes-Rahe life-event weights	858/1085	28 - 79	Life events	The association between job stress and breast cancer was determined in separate analysis	During the previous 3 years	All stages	Hormone replacement therapy	5.09 (3.41-8.50)	18
Helgesson 2003 [21]	Sweden	Prospective	1–6 on the stress scale	1462	38 - 60	Stressful events	None	During the previous 5 years	All stages	No description	2.1 (1.2-3.7)	20
Lillberg 2003 [22]	Finland	Prospective	Holmes-Rahe life-event weights	10808	>24	Stressful life events	None	During the previous 5 years	All stages	Oral contraceptives	1.07 (1.00-1.15)	20
Michael 2009 [23]	America	Prospective	Number of life events and amount of upset	84334	50 - 79	Life events	None	During the previous 1 years	All stages	No description	1.12 (1.01-1.25)	19

RR relative risk, CI confidence interval.