TABLE 3.
Multivariable 1 ORs (95% CIs) for intake of total caffeine and frequency of coffee and tea consumption at baseline, 2–4 y before diagnosis, and 0–3 y after diagnosis and risk of PMS: Nurses’ Health Study II PMS substudy, 1991–20051
| At baseline |
2–4 y before diagnosis |
0–3 y after diagnosis |
||||
| Median | OR (95% CI) | Median | OR (95% CI) | Median | OR (95% CI) | |
| Total caffeine | ||||||
| Q1 | 18 | 1 | 14 | 1 | 14 | 1 |
| Q2 | 82 | 0.84 (0.67, 1.05) | 80 | 0.77 (0.61, 0.98) | 76 | 0.80 (0.63, 1.01) |
| Q3 | 168 | 1.07 (0.85, 1.35) | 166 | 1.02 (0.80, 1.29) | 159 | 0.85 (0.67, 1.07) |
| Q4 | 354 | 1.00 (0.79, 1.28) | 350 | 1.06 (0.84, 1.34) | 327 | 0.89 (0.71, 1.13) |
| Q5 | 543 | 0.79 (0.61, 1.04) | 523 | 0.72 (0.55, 0.94) | 483 | 0.82 (0.65, 1.05) |
| P-trend | 0.31 | 0.33 | 0.60 | |||
| Total coffee | ||||||
| <1 cup/mo | 1 | 1 | 1 | |||
| 1 cup/mo–1 cup/wk | 1.25 (0.94, 1.67) | 1.23 (0.90, 1.67) | 1.33 (0.96, 1.84) | |||
| 2–6 cups/wk | 1.10 (0.83, 1.45) | 1.38 (1.03, 1.83) | 1.21 (0.89, 1.64) | |||
| 1 cup/d | 1.23 (0.96, 1.57) | 1.28 (1.00, 1.65) | 1.23 (0.96, 1.59) | |||
| 2–3 cups/d | 1.18 (0.95, 1.47) | 1.18 (0.96, 1.46) | 1.14 (0.92, 1.41) | |||
| ≥4 cups/d | 0.83 (0.61, 1.14) | 0.76 (0.56, 1.05) | 0.94 (0.69, 1.28) | |||
| P-trend | 0.43 | 0.22 | 0.71 | |||
| Caffeinated coffee | ||||||
| <1 cup/mo | 1 | 1 | 1 | |||
| 1 cup/mo–1 cup/wk | 1.17 (0.88, 1.55) | 1.40 (1.04, 1.88) | 0.91 (0.67, 1.25) | |||
| 2–6 cups/wk | 0.85 (0.64, 1.15) | 0.98 (0.72, 1.32) | 0.98 (0.72, 1.32) | |||
| 1 cup/d | 1.18 (0.93, 1.50) | 1.23 (0.97, 1.58) | 1.00 (0.79, 1.28) | |||
| 2–3 cups/d | 1.03 (0.83, 1.28) | 1.14 (0.92, 1.40) | 0.98 (0.79, 1.20) | |||
| ≥4 cups/d | 0.80 (0.58, 1.11) | 0.72 (0.52, 1.01) | 0.84 (0.62, 1.15) | |||
| P-trend | 0.33 | 0.25 | 0.48 | |||
| Decaffeinated coffee | ||||||
| <1 cup/mo | 1 | 1 | 1 | |||
| 1 cup/mo–1 cup/wk | 1.11 (0.90, 1.37) | 1.01 (0.81, 1.25) | 1.12 (0.91, 1.39) | |||
| 2–6 cups/wk | 0.95 (0.71, 1.26) | 1.17 (0.89, 1.54) | 1.39 (1.05, 1.85) | |||
| 1 cup/d | 1.33 (0.99, 1.79) | 1.00 (0.74, 1.35) | 1.00 (0.73, 1.37) | |||
| ≥2 cups/d | 1.14 (0.83, 1.57) | 1.10 (0.79, 1.51) | 1.08 (0.77, 1.50) | |||
| P-trend | 0.25 | 0.58 | 0.62 | |||
| Total tea2 | ||||||
| <1 cup/mo | 1 | 1 | 1 | |||
| 1 cup/mo–1 cup/wk | 0.92 (0.69, 1.22) | 0.92 (0.70, 1.22) | 1.00 (0.81, 1.24) | |||
| 2–6 cups/wk | 1.20 (0.89, 1.62) | 1.06 (0.78, 1.44) | 1.16 (0.92, 1.47) | |||
| 1 cup/d | 1.19 (0.84, 1.69) | 1.14 (0.80, 1.63) | 1.10 (0.85, 1.42) | |||
| ≥2 cups/d | 0.97 (0.70, 1.34) | 1.09 (0.79, 1.50) | 1.24 (0.98, 1.56) | |||
| P-trend | 0.90 | 0.37 | 0.06 | |||
| Caffeinated tea | ||||||
| <1 cup/mo | 1 | 1 | 1 | |||
| 1 cup/mo–1 cup/wk | 1.10 (0.90, 1.34) | 1.09 (0.90, 1.33) | 0.89 (0.74, 1.08) | |||
| 2–6 cups/wk | 1.08 (0.85, 1.36) | 0.92 (0.73, 1.16) | 1.06 (0.84, 1.34) | |||
| 1 cup/d | 0.95 (0.75, 1.20) | 0.98 (0.76, 1.26) | 0.85 (0.64, 1.13) | |||
| ≥2 cups/d | 1.06 (0.84, 1.36) | 1.12 (0.87, 1.44) | 1.06 (0.82, 1.38) | |||
| P-trend | 0.98 | 0.59 | 0.64 | |||
| Herbal tea2 | ||||||
| <1 cup/mo | 1 | 1 | 1 | |||
| 1 cup/mo–1 cup/wk | 1.20 (0.91, 1.57) | 1.03 (0.79, 1.34) | 1.11 (0.91, 1.35) | |||
| 2–6 cups/wk | 2.06 (1.48, 2.86) | 1.34 (0.96, 1.86) | 1.25 (0.98, 1.59) | |||
| ≥1 cups/d | 1.19 (0.85, 1.66) | 1.30 (0.94, 1.80) | 1.23 (0.98, 1.55) | |||
| P-trend | 0.06 | 0.06 | 0.05 | |||
Multivariable logistic regression models adjusted for diagnosis year (1993, 1994–1995, 1996–1997, 1998–1999, or 2000–2001); age; pack-years of smoking (0, 1–5, 6–10, 11–15, 16–20, or ≥21); parity (0, 1–2, 3–4, or ≥5); duration of oral contraceptive use (never or 1–23, 24–71, 72–119, or ≥120 mo); history of childhood trauma score (5, 6–10, 11–15, or ≥16); depression before PMS, depression medication; BMI [in kg/m2 (<20.0, 20.0–22.4, 22.5–24.9, 25.0–27.4, 27.5–29.9, or ≥30)]; physical activity (<3, 3 to <9, 9 to <18, 18 to <27, 27 to <42, or ≥42 metabolic equivalent task–hours/wk); and total intake of alcohol (0, >0 to <5, 5 to <10, 10 to <15, or ≥15 g/d), calcium, vitamin D, vitamin B-6, and potassium. PMS, premenstrual syndrome; Q, quintile.
Herbal tea not assessed until 1995; baseline for total and herbal tea is 1995.