Table 4. Relative risk of mortality by the presence of social network member and level of social strain, among 4,530 participants diagnosed with breast cancer from the WHI, 1993–2009.
| Total person- time |
High social strain | Low social strain | High social strain | Low social strain | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
|
|
|
|
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| All-cause death |
HR* | 95% CI | All-cause death |
HR* | 95% CI | Breast cancer death |
HR* | 95% CI | Breast cancer death |
HR* | 95% CI | ||
| Married | |||||||||||||
| No | 11,082 | 47 | 1.00 | 104 | 1.00 | 19 | 1.00 | 49 | 1.00 | ||||
| Yes | 20,101 | 66 | 1.12 | (0.73–1.72) | 137 | 0.98 | (0.74–1.31) | 40 | 1.83 | (0.96–3.48) | 82 | 1.26 | (0.84–1.91) |
| P value | 0.59 | 0.90 | 0.07 | 0.27 | |||||||||
| P-interaction | 0.54 | 0.23 | |||||||||||
| Relatives | |||||||||||||
| 0–3 | 8,519 | 22 | 1.00 | 71 | 1.00 | 10 | 1.00 | 33 | 1.00 | ||||
| 4–5 | 10,450 | 27 | 1.21 | 70 | 0.77 | (0.54–1.09) | 16 | 2.57 | (1.02–6.47) | 44 | 1.01 | (0.62–1.64) | |
| 6–9 | 9,632 | 48 | 2.06 | (1.16–3.65) | 70 | 0.76 | (0.53–1.09) | 25 | 3.39 | (1.40–8.17) | 37 | 0.83 | (0.50–1.40) |
| 10 or more | 2,583 | 16 | 1.53 | 30 | 1.22 | (0.76–1.94) | 8 | 2.53 | (0.84–7.59) | 17 | 1.40 | (0.74–2.68) | |
| P-continuous** | 0.10 | 0.98 | 0.07 | 0.56 | |||||||||
| P-interaction | 0.06 | 0.20 | |||||||||||
| Club participation | |||||||||||||
| No | 13,033 | 50 | 1.00 | 100 | 1.00 | 33 | 1.00 | 56 | 1.00 | ||||
| Yes | 18,150 | 63 | 0.98 | (0.66–1.45) | 141 | 1.05 | (0.80–1.37)1 | 26 | 0.59 | (0.33–1.05) | 75 | 1.07 | (0.74–1.55) |
| P value | 0.90 | 0.72 | 0.07 | 0.71 | |||||||||
| P-interaction | 0.78 | 0.08 | |||||||||||
| Religious participation | |||||||||||||
| No | 11,452 | 37 | 1.00 | 87 | 1.00 | 17 | 1.00 | 53 | 1.00 | ||||
| Yes | 19,731 | 76 | 1.05 | (0.69–1.58) | 154 | 1.00 | (0.76–1.31) | 42 | 1.21 | (0.65–2.27) | 78 | 0.82 | (0.57–1.20) |
| P value | 0.83 | 0.70 | 0.55 | 0.31 | |||||||||
| P-interaction | 0.73 | 0.17 | |||||||||||
Multivariate-adjusted models adjusted for age, study arm (OS, CT [ref]), time between diagnosis and assessment of social networks, race (white, nonwhite[ref]), income (<$20,000, 20–<50 K, 50–<100 K, $100 K+ [ref]), education (≤HS, >HS-college graduate, post-graduate [ref]), family history of breast cancer (no history [ref], 1 first-degree relative before age 45, 2+ relatives), cancer stage at diagnosis (localized [ref], regional, distant), tumor size (≤3 mm [ref], >3 mm), HER-2 neu status (positive, negative[ref]), nodal status (no involvement [ref], any involvement), estrogen-receptor status (positive, negative [ref]), age at first birth (never pregnant, never had term pregnancy, <20, 20−29, ≥30 years [ref]), smoking status (never [ref], past, current), BMI (<25 [reference] 25−29, 30+ kg/m2), physical activity (<3 [ref], 3−17, 18+ mets/week), comorbidity (yes, no[ref]), mammography within the last two years (yes, no [ref])
P value, continuous variable
Results in bold were statistically significant (P<0.05)