Table 3.
Multivariable-adjusted relative risks for surgically-treated fibroids according to energy balance related factors in the California Teachers Study.
| Surgery for fibroids during study follow-up period, 1995-2006 | |||
|---|---|---|---|
| Woman Years | n | Multivariable adjusted RR (95% CI)*a | |
| Daily alcohol intake (g) | |||
| None | 248237 | 561 | 0.96 (0.87, 1.07) |
| <20 | 444657 | 1011 | 1.00 |
| ≥20 | 61404 | 156 | 1.33 (1.12, 1.58) |
| Unknown | 41584 | 63 | |
| Lifetime moderate and strenuous physical activity b | |||
| Low | 83851 | 154 | 1.02 (0.86, 1.21) |
| Intermediate | 388484 | 903 | 1.00 |
| High | 319080 | 725 | 0.95 (0.86, 1.05) |
| Unknown | 4466 | 8 | |
| Body mass index (kg/m2) | |||
| Underweight (<18.50) | 22562 | 45 | 0.97 (0.72, 1.31) |
| Normal weight (18.50-24.99) | 468749 | 985 | 1.00 |
| Overweight (25.00-29.99) | 178437 | 434 | 1.26 (1.13, 1.41) |
| Obese (≥30.00) | 101738 | 288 | 1.33 (1.17, 1.52) |
| Unknown | 24396 | 38 | |
| p trend | <0.001 | ||
| Change in weight since age 18 (kg) c | |||
| Same weight or weight loss | 169149 | 343 | 0.87 (0.76, 1.01) |
| Weight gain <10.00 | 289062 | 623 | 1.00 |
| Weight gain 10.00-19.99 | 182750 | 441 | 1.16(1.02, 1.31) |
| Weight gain ≥20.00 | 124919 | 339 | 1.23 (1.08, 1.41) |
| Unknown | 30002 | 44 | |
| p trend | <0.001 | ||
*
RR, relative risk; CI, confidence interval.
a
Adjusted for race/ethnicity, and family history of fibroids, and stratified by age.
b
Low activity is no strenuous or moderate activity with cumulative duration that is more than 30 minutes per week. High activity is over 3 hours a week of either moderate or strenuous physical activity.
c
Additionally adjusted for body mass index at age 18.