Table 3

Crude and adjusted ORsa (95% CI) of epithelial ovarian cancer for tea drinkingb

No. of casesNo. of controlsCrude OR95% CIAdjusted OR95% CI
Years of tea drinking
 01131661.01.0
 <15772220.510.36–0.730.470.32–0.70
 15–30421440.430.28–0.650.430.28–0.68
 >30221200.270.16–0.450.230.13–0.41
 χ2 for trendc36.10d35.71d
Overall tea consumption
 Never or seldom1131661.01.0
 At most once a week341030.490.31–0.770.440.27–0.72
 2–6 times a week271050.380.23–0.610.370.22–0.63
 At least once a day802780.420.30–0.600.390.27–0.57
 χ2 for trendc30.73d30.06d
Green tea only
 Never or seldom1131661.01.0
 At most once a week25750.490.29–0.820.420.24–0.73
 2–6 times a week23850.400.24–0.670.400.23–0.70
 At least once a day762430.460.32–0.650.430.30–0.63
 χ2 for trendc32.79d31.78d
Black or Oolong tea
 Never or seldom1131661.01.0
 At most once a week5120.610.21–1.790.980.32–3.01
 2–6 times a week1130.110.02–0.880.130.02–1.04
 At least once a day1140.110.01–0.810.060.01–0.50
 χ2 for trendc36.43d39.68d
Green and black tea
 Never or seldom1131661.01.0
 At most once a week4160.370.12–1.130.260.07–0.96
 2–6 times a week370.630.16–2.490.440.08–2.39
 At least once a day3210.210.06–0.720.250.07–0.87
 χ2 for trendc33.78d32.07d
  • a Estimates from multivariate logistic regression models included terms for age at interview (in years; continuous), education (none, primary, secondary, tertiary), living area (urban, rural), BMI (5 years ago; continuous), tobacco smoking (never, ever), alcohol consumption (never, ever), coffee drinking (never, ever), family income (yuan per month; ≤1000, 1001–2000, ≥2001), marital status (never married, married, widowed or divorced or separated), menopause status (no, yes), parity (full-term pregnancy; continuous), tubal ligation (no, yes), oral contraceptive use (no, yes), physical activity (never, ever), and family history of ovarian cancer (no, yes).

  • b Never or seldom, or zero is the reference category.

  • c Ordinal quantity of tea drinking was tested for linear trend.

  • d P < 0.001.