Table 2.
Hazard ratios and 95% confidence intervals for the association between physical activity and incident epithelial ovarian cancer in Nurses’ Health Study (1986–2010) and Nurses’ Health Study II (1989–2011)
| Total physical activity in MET-hours/week, HR (95% CI) | |||||
|---|---|---|---|---|---|
| <3 | 3 – <9 | 9 – <18 | 18 – <27 | ≥27 | |
| Baseline activity1 | |||||
| NHS (N=601 cases) | |||||
| Cases/person-years | 142/328,234 | 164/329,409 | 121/240,787 | 66/137,509 | 108/187,308 |
| Age-adjusted | 0.87 (0.69, 1.09) | 1.00 (ref) | 0.99 (0.78, 1.25) | 0.95 (0.71, 1.27) | 1.14 (0.89, 1.45) |
| Multivariable2 | 0.87 (0.69, 1.09) | 1.00 (ref) | 0.98 (0.78, 1.24) | 0.94 (0.71, 1.26) | 1.13 (0.88, 1.44) |
| Multivariable + BMI3 | 0.87 (0.69, 1.09) | 1.00 (ref) | 0.98 (0.77, 1.24) | 0.94 (0.70, 1.25) | 1.12 (0.87, 1.43) |
| NHSII (N=214 cases) | |||||
| Cases/person-years | 28/244,747 | 45/377,475 | 45/351,689 | 25/223,044 | 71/440,517 |
| Age-adjusted | 0.93 (0.58, 1.49) | 1.00 (ref) | 1.07 (0.71, 1.62) | 0.94 (0.58, 1.54) | 1.41 (0.97, 2.06) |
| Multivariable2 | 0.94 (0.59, 1.52) | 1.00 (ref) | 1.08 (0.71, 1.63) | 0.91 (0.56, 1.49) | 1.35 (0.92, 1.96) |
| Multivariable + BMI | 0.92 (0.57, 1.47) | 1.00 (ref) | 1.11 (0.73, 1.68) | 0.96 (0.59, 1.57) | 1.46 (1.00, 2.13) |
| Pooled (N=815 cases) | |||||
| Age-adjusted | 0.88 (0.72, 1.08) | 1.00 (ref) | 1.00 (0.82, 1.23) | 0.94 (0.74, 1.21) | 1.22 (1.00, 1.49) |
| Multivariable2 | 0.89 (0.72, 1.09) | 1.00 (ref) | 1.00 (0.82, 1.23) | 0.94 (0.73, 1.20) | 1.20 (0.98, 1.47) |
| Multivariable + BMI | 0.88 (0.72, 1.08) | 1.00 (ref) | 1.01 (0.82, 1.24) | 0.94 (0.74, 1.21) | 1.22 (1.00, 1.50) |
| Recent activity4 | |||||
| NHS (N=601 cases) | |||||
| Cases/person-years | 133/267,401 | 149/292,538 | 120/255,470 | 76/157,266 | 123/250,572 |
| Age-adjusted | 0.97 (0.77, 1.23) | 1.00 (ref) | 0.90 (0.71, 1.15) | 0.93 (0.71, 1.23) | 0.95 (0.75, 1.21) |
| Multivariable2 | 0.98 (0.78, 1.24) | 1.00 (ref) | 0.91 (0.71, 1.15) | 0.93 (0.70, 1.23) | 0.94 (0.74, 1.20) |
| Multivariable + BMI | 0.98 (0.77, 1.24) | 1.00 (ref) | 0.90 (0.71, 1.15) | 0.92 (0.70, 1.22) | 0.93 (0.73, 1.18) |
| NHSII (N=214 cases) | |||||
| Cases/person-years | 39/278,823 | 45/376,775 | 42/353,913 | 34/221,238 | 54/406,722 |
| Age-adjusted | 1.11 (0.72, 1.70) | 1.00 (ref) | 1.01 (0.66, 1.54) | 1.29 (0.82, 2.01) | 1.13 (0.76, 1.69) |
| Multivariable2 | 1.10 (0.71, 1.69) | 1.00 (ref) | 0.99 (0.65, 1.51) | 1.27 (0.81, 1.99) | 1.09 (0.73, 1.62) |
| Multivariable + BMI | 1.04 (0.68, 1.61) | 1.00 (ref) | 1.05 (0.68, 1.60) | 1.38 (0.88, 2.16) | 1.23 (0.82, 1.84) |
| Pooled (N=815 cases) | |||||
| Age-adjusted | 1.01 (0.82, 1.24) | 1.00 (ref) | 0.93 (0.75, 1.14) | 1.02 (0.80, 1.29) | 0.99 (0.81, 1.22) |
| Multivariable2 | 1.01 (0.82, 1.24) | 1.00 (ref) | 0.93 (0.75, 1.14) | 1.02 (0.80, 1.29) | 0.98 (0.80, 1.21) |
| Multivariable + BMI | 1.00 (0.81, 1.23) | 1.00 (ref) | 0.94 (0.76, 1.16) | 1.03 (0.81, 1.31) | 1.01 (0.82, 1.24) |
| Cumulative average | |||||
| NHS (N=601 cases) | |||||
| Cases/person-years | 79/177,319 | 147/326,958 | 163/325,827 | 105/182,010 | 107/211,133 |
| Age-adjusted | 1.09 (0.83, 1.44) | 1.00 (ref) | 1.07 (0.86, 1.34) | 1.23 (0.96, 1.59) | 1.10 (0.86, 1.41) |
| Multivariable2 | 1.11 (0.84, 1.46) | 1.00 (ref) | 1.07 (0.85, 1.33) | 1.22 (0.95, 1.57) | 1.09 (0.85, 1.40) |
| Multivariable + BMI | 1.10 (0.83, 1.45) | 1.00 (ref) | 1.07 (0.85, 1.33) | 1.21 (0.94, 1.56) | 1.08 (0.83, 1.38) |
| NHSII (N=214 cases) | |||||
| Cases/person-years | 26/159,552 | 41/383,431 | 49/424,901 | 33/264,760 | 65/404,827 |
| Age-adjusted | 1.64 (1.00, 2.69) | 1.00 (ref) | 1.08 (0.71, 1.63) | 1.17 (0.74, 1.86) | 1.63 (1.10, 2.42) |
| Multivariable2 | 1.62 (0.99, 2.65) | 1.00 (ref) | 1.06 (0.70, 1.60) | 1.13 (0.71, 1.79) | 1.55 (1.04, 2.29) |
| Multivariable + BMI | 1.55 (0.94, 2.55) | 1.00 (ref) | 1.11 (0.73, 1.69) | 1.22 (0.77, 1.94) | 1.76 (1.18, 2.62) |
| Pooled (N=815 cases) | |||||
| Age-adjusted | 1.20 (0.94, 1.52) | 1.00 (ref) | 1.07 (0.88, 1.30) | 1.21 (0.97, 1.51) | 1.24 (1.01, 1.53) |
| Multivariable2 | 1.21 (0.95, 1.54) | 1.00 (ref) | 1.06 (0.87, 1.30) | 1.20 (0.96, 1.50) | 1.22 (0.99, 1.51) |
| Multivariable + BMI | 1.19 (0.94, 1.52) | 1.00 (ref) | 1.08 (0.88, 1.31) | 1.22 (0.97, 1.52) | 1.26 (1.02, 1.55) |
Defined as the first reported physical activity measure during the study follow-up
Stratified by age, calendar years and cohort (for pooled analysis), and adjusted for menopausal status (premenopausal, postmenopausal), duration of oral contraceptive use (never, <1, 1–5, >5 years), parity (nulliparous, 1, 2, 3, >3 children), history of tubal ligation (yes, no), history of hysterectomy (yes, no), duration of postmenopausal hormone use by type (never, <5, 5–10, >10 years for estrogen only and estrogen plus progesterone separately), family history of breast or ovarian cancer (yes, no), cumulative average intake of lactose and caffeine (in quintiles plus a missing indicator)
BMI was evaluated as <20, 20 to <25, 25 to <30, ≥30 kg/m2
Physical activity 2–4 years prior to ovarian cancer diagnosis