Table 4.

Multivariable relative risk and 95% confidence interval for the association between physical activity and death by cause according to estrogen receptor status among women in the California Teachers Study

Physical activity (h/wk/y)Breast cancer deaths (n = 221)Death due to any cause (n = 460)
ER positive (n = 2,549)ER negative (n = 450) ER positive (n = 2,549)ER negative (n = 450)
RR (95% CI)RR (95% CI)RR (95% CI)RR (95% CI)
Long-term physical activity
    Combined*
        Low1.001.001.001.00
        Intermediate0.66 (0.41-1.06)0.42 (0.19-0.95)0.85 (0.63-1.17)0.47 (0.25-0.91)
        High0.46 (0.26-0.80)0.33 (0.13-0.83)0.78 (0.56-1.11)0.33 (0.15-0.74)
        P trend0.0070.030.180.008
Recent physical activity
    Combined*
        Low1.001.001.001.00
        Intermediate1.13 (0.71-1.80)0.87 (0.42-1.80)0.97 (0.73-1.29)0.65 (0.35-1.22)
        High1.06 (0.62-1.81)1.18 (0.51-2.74)0.89 (0.64-1.23)0.71 (0.35-1.46)
        P trend0.830.770.490.26

NOTE: All models are stratified by age in years and adjusted for race, BMI, total caloric intake, number of comorbid conditions and estrogen receptor status.

Abbreviation: ER, estrogen receptor.

  • *Long-term strenuous and moderate activity summary variable classifies women with no activity >0.5 h/wk/y activity into the low group, those with at least one of moderate or strenuous activity >3 h/wk/y into the high group, and all others, that is, those with some activity that is >0.5 h/wk/y and ≤3 h/wk/y but not >3 h/wk/y into the intermediate group.

  • P trend is the log-relative risk across categories (1, 2 and 3) of the strenuous-moderate summary variable.