Table 3.
Hazard Ratios for Early Menopause According to Category of Adolescent Intake of Total and Individual Dairy Foods, Nurses’ Health Study II, 1991–2011
| Dairy Food and Intake Measure | No. of Cases | No. of Person-Years | Model 1a | Model 2b | ||
|---|---|---|---|---|---|---|
| HR | 95% CI | HR | 95% CI | |||
| Total dairy food, no. of servings | ||||||
| <4/day | 60 | 27,571 | 1.00 | Referent | 1.00 | Referent |
| 4–5/day | 112 | 56,833 | 0.92 | 0.67, 1.27 | 0.93 | 0.68, 1.28 |
| ≥6/day | 840 | 462,393 | 0.86 | 0.66, 1.11 | 0.86 | 0.66, 1.12 |
| Per 1-serving/day increment | 1.00 | 0.99, 1.01 | 1.00 | 0.99, 1.01 | ||
| P for trend | 0.60 | 0.64 | ||||
| Skim milk, no. of servings | ||||||
| Almost never | 748 | 379,718 | 1.00 | Referent | 1.00 | Referent |
| 1/month–1/day | 135 | 86,634 | 0.90 | 0.74, 1.08 | 0.92 | 0.76, 1.10 |
| ≥2/day | 129 | 80,445 | 0.89 | 0.74, 1.08 | 0.92 | 0.76, 1.11 |
| Per 1-serving/day increment | 0.95 | 0.89, 1.02 | 0.96 | 0.90, 1.03 | ||
| P for trend | 0.17 | 0.29 | ||||
| Whole milk, no. of servings | ||||||
| Almost never | 414 | 241,591 | 1.00 | Referent | 1.00 | Referent |
| 1/month–6/week | 207 | 100,797 | 1.10 | 0.92, 1.30 | 1.07 | 0.90, 1.27 |
| 1/day | 118 | 64,149 | 0.99 | 0.81, 1.22 | 0.98 | 0.80, 1.20 |
| ≥2/day | 273 | 140,260 | 1.02 | 0.87, 1.19 | 1.01 | 0.86, 1.18 |
| Per 1-serving/day increment | 1.00 | 0.95, 1.05 | 1.00 | 0.95, 1.05 | ||
| P for trend | 0.95 | 0.89 | ||||
Abbreviations: CI, confidence interval; HR, hazard ratio; MET, metabolic equivalent of task.
a Model 1 adjusted for age (months; continuous).
b Model 2 adjusted for age (months; continuous), race (white or nonwhite), physical activity during high school (MET-hours/week; continuous), body mass index at age 18 years (weight (kg)/height (m)2; continuous), and smoking during high school (pack-years; continuous).