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 5Â 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 1Â years | All stages | No description | 1.12 (1.01-1.25) | 19 |