Table 2.
Hazard ratio of breast cancer event by category of social network size in the LACE cohort (N=2,264).
| Social network size | ||||
|---|---|---|---|---|
| Socially isolated | Moderately integrated | Socially integrated | p-value** | |
| N† | 797 | 706 | 761 | |
| Person-years | 8,117 | 7,123 | 7,897 | |
| Recurrence | 148 | 111 | 124 | |
| Age-adjusted* 95% CI | 1.16 (0.91–1.47) | 1.00 (0.77–1.29) | 1.00 | 0.21 |
| MV-adjusted model 1‡ 95% CI | 1.09 (0.85–1.41) | 0.94 (0.72–1.22) | 1.00 | 0.55 |
| MV-adjusted model 2 95% CI | 1.08 (0.84–1.40) | 0.95 (0.71–1.27) | 1.00 | 0.66 |
| MV-adjusted model 3 95% CI | 1.03 (0.73–1.42) | 1.08 (0.83–1.41) | 1.00 | 0.36 |
| Breast cancer mortality | 85 | 59 | 71 | |
| Age-adjusted 95% CI | 1.15 (0.84–1.57) | 0.91 (0.64–1.29) | 1.00 | 0.24 |
| MV-adjusted model 1 95% CI | 1.08 (0.77–1.52) | 0.83 (0.53–1.18) | 1.00 | 0.61 |
| MV-adjusted model 2 95% CI | 1.12 (0.79–1.60) | 0.91 (0.61–1.36) | 1.00 | 0.66 |
| MV-adjusted model 3 95% CI | 1.16 (0.76–1.77) | 1.04 (0.72–1.49) | 1.00 | 0.50 |
| All-cause mortality | 170 | 122 | 109 | |
| Age-adjusted 95% CI | 1.48 (1.16–1.88) | 1.23 (0.95–1.59) | 1.00 | <0.001 |
| MV-adjusted model 1 95% CI | 1.34 (1.03–1.73) | 1.08 (0.83–1.41) | 1.00 | 0.008 |
| MV-adjusted model 2 95% CI | 1.34 (1.03–1.75) | 1.11 (0.62–1.51) | 1.00 | 0.02 |
| MV-adjusted model 3 95% CI | 1.50 (1.11–2.03) | 1.13 (0.86–1.49) | 1.00 | 0.004 |
| Mortality from other causes | 85 | 63 | 38 | |
| Age-adjusted 95% CI | 2.07 (1.41–3.03) | 1.77 (1.18–2.65) | 1.00 | <0.001 |
| MV-adjusted model 1 95% CI | 1.79 (1.19–2.68) | 1.45 (0.95–2.21) | 1.00 | <0.001 |
| MV-adjusted model 2 95% CI | 1.68 (1.09–22.58) | 1.36 (0.87–2.14) | 1.00 | 0.005 |
| MV-adjusted model 3 95% CI | 1.97 (1.25–3.10) | 1.23 (0.80–1.89) | 1.00 | <0.001 |
Age-adjusted model adjusted for age (continuous) and time between diagnosis and assessment of social networks. Age-adjusted model employed mean imputation. Multivariate-adjusted (MV-) adjusted model 1 employed mean imputation. MV-adjusted model 2 employed multiple imputation. MV-adjusted model 3 employed the assumption of meaningful nonresponse, that nonresponse signified the participant did not have a social network member. For mean and multiple imputation, ranges of values were 0–4 for socially isolated women, 4.1–<5.5 for moderately integrated women, and 5.5–8.0 for socially integrated women. For the assumption of meaningful nonresponse, the ranges were 0–<4, 4–<6, and 6–8. These distributions reflect approximate tertiles.
p-value, continuous variable
N based on values derived with mean imputation.
Multivariate-adjusted models adjusted for age at diagnosis, time between diagnosis and assessment of social networks, race (white, nonwhite[ref]), education (<college graduate [ref], college graduate), any family history of breast cancer (no history [ref], yes), cancer stage at diagnosis (1 [ref], 2, 3), tumor size (continuous), HER-2 neu status (positive, negative[ref]), nodal status (no involvement [ref], any involvement), estrogen-receptor status (positive, negative [ref]), chemotherapy (yes, no [ref]), radiation (yes, no [ref]), tamoxifen (never, past, current [ref]), age at menarche (continuous), age at first birth (never had pregnancy lasting at least 5 months, <20 [ref], 20–29,30–39, ≥40 years [ref]), parity (0, 1, 2, 3, 4+ [ref] pregnancies ≥ 5 months), menopausal status (pre[ref], post), smoking status (never [ref], past, current), body mass index (<25 [reference] 25–29, 30+ kg/m2), physical activity (quartiles, quartile 1 [ref]), and alcohol intake (0 [ref], >0 svg/wk).