ORs and 95% CIs for an association between low-, moderate-, and high-intensity outdoor activity episodes at ages 10 to 19, 20 to 29, and 45 to 54, and breast cancer in cases and controls
| . | Cases (%) . | Controls (%) . | OR* (95% CI) . | OR† (95% CI) . | ||||
|---|---|---|---|---|---|---|---|---|
| Low-intensity outdoor activity‡ | ||||||||
| Ages 10-19 | ||||||||
| <1 | 285 (31) | 250 (23) | 1.00 | 1.00 | ||||
| 1-98 | 215 (23) | 259 (24) | 0.76 (0.59-0.97) | 0.80 (0.61-1.04) | ||||
| 99-313 | 216 (23) | 287 (26) | 0.69 (0.54-0.88) | 0.76 (0.58-0.99) | ||||
| 314+ | 209 (23) | 295 (27) | 0.65 (0.51-0.83) | 0.69 (0.53-0.91) | ||||
| Ages 20-29 | ||||||||
| <1 | 295 (32) | 302 (27) | 1.00 | 1.00 | ||||
| 1-80 | 188 (20) | 237 (21) | 0.83 (0.65-1.07) | 0.88 (0.68-1.15) | ||||
| 81-240 | 268 (29) | 337 (31) | 0.83 (0.66-1.04) | 0.90 (0.70-1.14) | ||||
| 241+ | 179 (19) | 229 (21) | 0.81 (0.63-1.05) | 0.85 (0.65-1.11) | ||||
| Ages 45-54 | ||||||||
| <64 | 93 (23) | 108 (23) | 1.00 | 1.00 | ||||
| 64-143 | 100 (25) | 115 (25) | 1.01 (0.69-1.49) | 1.04 (0.70-1.56) | ||||
| 144-287 | 97 (24) | 116 (25) | 0.97 (0.66-1.43) | 0.90 (0.60-1.36) | ||||
| 288+ | 114 (28) | 124 (27) | 1.07 (0.73-1.56) | 1.01 (0.68-1.50) | ||||
| Moderate-intensity outdoor activity‡ | ||||||||
| Ages 10-19 | ||||||||
| <295 | 263 (28) | 246 (22) | 1.00 | 1.00 | ||||
| 295-672 | 226 (24) | 297 (27) | 0.72 (0.56-0.92) | 0.70 (0.54-0.90) | ||||
| 673-840 | 253 (27) | 272 (25) | 0.87 (0.68-1.12) | 0.87 (0.67-1.12) | ||||
| 841+ | 187 (20) | 287 (26) | 0.60 (0.47-0.78) | 0.58 (0.44-0.76) | ||||
| Ages 20-29 | ||||||||
| <225 | 275 (29) | 236 (21) | 1.00 | 1.00 | ||||
| 225-540 | 234 (25) | 292 (26) | 0.69 (0.54-0.88) | 0.74 (0.57-0.95) | ||||
| 541-840 | 237 (25) | 304 (27) | 0.66 (0.52-0.85) | 0.68 (0.53-0.88) | ||||
| 841+ | 191 (20) | 280 (25) | 0.57 (0.44-0.73) | 0.59 (0.45-0.77) | ||||
| Ages 45-54 | ||||||||
| <240 | 94 (14) | 116 (15) | 1.00 | 1.00 | ||||
| 240-504 | 182 (27) | 195 (25) | 1.14 (0.81-1.60) | 1.10 (0.77-1.56) | ||||
| 504-839 | 144 (21) | 170 (22) | 1.03 (0.73-1.47) | 0.98 (0.68-1.41) | ||||
| 840+ | 260 (38) | 302 (39) | 1.04 (0.75-1.44) | 0.99 (0.70-1.38) | ||||
| High-intensity outdoor activity‡ | ||||||||
| Ages 10-19 | ||||||||
| <141 | 290 (31) | 222 (20) | 1.00 | 1.00 | ||||
| 141-416 | 223 (24) | 285 (26) | 0.61 (0.48-0.79) | 0.62 (0.47-0.80) | ||||
| 417-840 | 216 (23) | 300 (27) | 0.56 (0.44-0.72) | 0.57 (0.44-0.74) | ||||
| 841+ | 205 (22) | 295 (27) | 0.55 (0.43-0.710 | 0.59 (0.45-0.77) | ||||
| Ages 20-29 | ||||||||
| <1 | 295 (32) | 257 (23) | 1.00 | 1.00 | ||||
| 1-120 | 229 (24) | 291 (26) | 0.71 (0.56-0.90) | 0.75 (0.59-0.97) | ||||
| 121-324 | 200 (21) | 261 (24) | 0.68 (0.53-0.88) | 0.75 (0.57-0.97) | ||||
| 325+ | 211 (23) | 297 (27) | 0.65 (0.51-0.83) | 0.70 (0.54-0.90) | ||||
| Ages 45-54 | ||||||||
| <48 | 67 (15) | 72 (13) | 1.00 | 1.00 | ||||
| 48-119 | 80 (18) | 87 (16) | 0.99 (0.63-1.56) | 0.96 (0.60-1.53) | ||||
| 120-269 | 129 (29) | 163 (30) | 0.84 (0.56-1.27) | 0.77 (0.51-1.18) | ||||
| 270+ | 174 (39) | 224 (41) | 0.83 (0.56-1.22) | 0.79 (0.53-1.18) | ||||
| . | Cases (%) . | Controls (%) . | OR* (95% CI) . | OR† (95% CI) . | ||||
|---|---|---|---|---|---|---|---|---|
| Low-intensity outdoor activity‡ | ||||||||
| Ages 10-19 | ||||||||
| <1 | 285 (31) | 250 (23) | 1.00 | 1.00 | ||||
| 1-98 | 215 (23) | 259 (24) | 0.76 (0.59-0.97) | 0.80 (0.61-1.04) | ||||
| 99-313 | 216 (23) | 287 (26) | 0.69 (0.54-0.88) | 0.76 (0.58-0.99) | ||||
| 314+ | 209 (23) | 295 (27) | 0.65 (0.51-0.83) | 0.69 (0.53-0.91) | ||||
| Ages 20-29 | ||||||||
| <1 | 295 (32) | 302 (27) | 1.00 | 1.00 | ||||
| 1-80 | 188 (20) | 237 (21) | 0.83 (0.65-1.07) | 0.88 (0.68-1.15) | ||||
| 81-240 | 268 (29) | 337 (31) | 0.83 (0.66-1.04) | 0.90 (0.70-1.14) | ||||
| 241+ | 179 (19) | 229 (21) | 0.81 (0.63-1.05) | 0.85 (0.65-1.11) | ||||
| Ages 45-54 | ||||||||
| <64 | 93 (23) | 108 (23) | 1.00 | 1.00 | ||||
| 64-143 | 100 (25) | 115 (25) | 1.01 (0.69-1.49) | 1.04 (0.70-1.56) | ||||
| 144-287 | 97 (24) | 116 (25) | 0.97 (0.66-1.43) | 0.90 (0.60-1.36) | ||||
| 288+ | 114 (28) | 124 (27) | 1.07 (0.73-1.56) | 1.01 (0.68-1.50) | ||||
| Moderate-intensity outdoor activity‡ | ||||||||
| Ages 10-19 | ||||||||
| <295 | 263 (28) | 246 (22) | 1.00 | 1.00 | ||||
| 295-672 | 226 (24) | 297 (27) | 0.72 (0.56-0.92) | 0.70 (0.54-0.90) | ||||
| 673-840 | 253 (27) | 272 (25) | 0.87 (0.68-1.12) | 0.87 (0.67-1.12) | ||||
| 841+ | 187 (20) | 287 (26) | 0.60 (0.47-0.78) | 0.58 (0.44-0.76) | ||||
| Ages 20-29 | ||||||||
| <225 | 275 (29) | 236 (21) | 1.00 | 1.00 | ||||
| 225-540 | 234 (25) | 292 (26) | 0.69 (0.54-0.88) | 0.74 (0.57-0.95) | ||||
| 541-840 | 237 (25) | 304 (27) | 0.66 (0.52-0.85) | 0.68 (0.53-0.88) | ||||
| 841+ | 191 (20) | 280 (25) | 0.57 (0.44-0.73) | 0.59 (0.45-0.77) | ||||
| Ages 45-54 | ||||||||
| <240 | 94 (14) | 116 (15) | 1.00 | 1.00 | ||||
| 240-504 | 182 (27) | 195 (25) | 1.14 (0.81-1.60) | 1.10 (0.77-1.56) | ||||
| 504-839 | 144 (21) | 170 (22) | 1.03 (0.73-1.47) | 0.98 (0.68-1.41) | ||||
| 840+ | 260 (38) | 302 (39) | 1.04 (0.75-1.44) | 0.99 (0.70-1.38) | ||||
| High-intensity outdoor activity‡ | ||||||||
| Ages 10-19 | ||||||||
| <141 | 290 (31) | 222 (20) | 1.00 | 1.00 | ||||
| 141-416 | 223 (24) | 285 (26) | 0.61 (0.48-0.79) | 0.62 (0.47-0.80) | ||||
| 417-840 | 216 (23) | 300 (27) | 0.56 (0.44-0.72) | 0.57 (0.44-0.74) | ||||
| 841+ | 205 (22) | 295 (27) | 0.55 (0.43-0.710 | 0.59 (0.45-0.77) | ||||
| Ages 20-29 | ||||||||
| <1 | 295 (32) | 257 (23) | 1.00 | 1.00 | ||||
| 1-120 | 229 (24) | 291 (26) | 0.71 (0.56-0.90) | 0.75 (0.59-0.97) | ||||
| 121-324 | 200 (21) | 261 (24) | 0.68 (0.53-0.88) | 0.75 (0.57-0.97) | ||||
| 325+ | 211 (23) | 297 (27) | 0.65 (0.51-0.83) | 0.70 (0.54-0.90) | ||||
| Ages 45-54 | ||||||||
| <48 | 67 (15) | 72 (13) | 1.00 | 1.00 | ||||
| 48-119 | 80 (18) | 87 (16) | 0.99 (0.63-1.56) | 0.96 (0.60-1.53) | ||||
| 120-269 | 129 (29) | 163 (30) | 0.84 (0.56-1.27) | 0.77 (0.51-1.18) | ||||
| 270+ | 174 (39) | 224 (41) | 0.83 (0.56-1.22) | 0.79 (0.53-1.18) | ||||
ORs with 95% CIs adjusted for reference age.
ORs with 95% CIs adjusted for reference age, ethnicity, family history in first-degree relatives, ever breast-fed, education, age menarche, and age at first birth.
Number of outdoor activity episodes derived from reported outdoor activities done for at least 30 min between 9 a.m. and 5 p.m. at least once per month during June, July, and August along with frequency (days per week or month) and duration (number of years) and classified as low, moderate, or high intensity.