Table 1.
Characteristics of the study population (5,911 cases and 16,172 controls) and coffee consumption category according to age, gender and smoking status
| Characteristics | Coffee consumption | Mean (± SD) cups/day | p valuea | p interaction | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Total | Never | Ever | ≤ 1 cups/day | 1–2 cups/day | 2–3 cups/day | 3–4 cups/day | > 4 cups/day | ||||
| n (%) | 22,083 (100) | 2,372 (10.74) | 19,711 (89.26) | 2,752 (12.46) | 3,616 (16.37) | 2,962 (13.41) | 2,750 (12.45) | 7,631 (34.56) | 4.00 (±3.97) | < 0.001 | |
| Case (%) | 5,911 (100) | 499 (8.44) | 5,412 (91.56) | 659 (11.15) | 1,077 (18.22) | 716 (12.11) | 801 (13.55) | 2,159 (36.53) | 4.58 (±4.84) | ||
| Control (%) | 16,172 (100) | 1,873 (11.58) | 14,299 (88.42) | 2,093 (12.94) | 2,539 (15.70) | 2,246 (13.89) | 1,949 (12.05) | 5,472 (33.84) | 3.78 (±3.58) | ||
| Gender | 0.16 | ||||||||||
| Male (%) | |||||||||||
| Case | 4,639 (100) | 369 (7.95) | 4,270 (92.05) | 488 (10.52) | 865 (18.65) | 560 (12.07) | 646 (13.93) | 1,711 (36.88) | 4.70 (±4.99) | < 0.001 | |
| Control | 8,983 (100) | 1,002 (11.15) | 7,981 (88.85) | 1,240 (13.80) | 1,468 (16.34) | 1,240 (13.80) | 1,114 (12.40) | 2,919 (32.49) | 3.84 (±3.98) | ||
| Female (%) | |||||||||||
| Case | 1,272 (100) | 130 (10.22) | 1,142 (89.78) | 171 (13.44) | 212 (16.67) | 156 (12.26) | 155 (12.19) | 448 (35.22) | 4.13 (±4.21) | 0.06 | |
| Control | 7,189 (100) | 871 (12.12) | 6,318 (87.88) | 853 (11.87) | 1,071 (14.90) | 1,006 (13.99) | 835 (11.61) | 2,553 (35.51) | 3.71 (±3.01) | ||
| Age (Mean ± SD) | |||||||||||
| Case | 5,911 (100) | 60.48 (± 12.70) | 5, 412 (91.56) | 65.38 (±9.88) | 64.36 (± 10.36) | 64.34 (±8.65) | 61.61 (±9.98) | 59.88 (±9.21) | 4.52 (±4.82) | < 0.001 | 0.17 |
| Control | 16,172 (100) | 59.92 (±8.49) | 14,299 (88.42) | 61.18 (±8.52) | 61.94 (±8.80) | 61.57 (±8.15) | 60.52 (±9.32) | 58.92 (±10.13) | 3.80 (±3.59) | ||
| Smoking status | |||||||||||
| Current smokers (%) | 0.001 | ||||||||||
| Case | 2,317 (100) | 140 (6.04) | 2,177 (93.96) | 176 (7.60) | 417 (18.00) | 258 (11.14) | 359 (15.49) | 967 (41.74) | 4.95 (±4.60) | < 0.001 | |
| Control | 5,350 (100) | 357 (6.67) | 4,993 (93.33) | 324 (6.06) | 782 (14.62) | 478 (8.93) | 751 (14.04) | 2,658 (49.68) | 4.92 (±3.75) | ||
| Former smokers (%) | |||||||||||
| Case | 2,491 (100) | 187 (7.51) | 2,304 (92.49) | 310 (12.44) | 412 (16.54) | 356 (14.29) | 298 (11.96) | 928 (37.25) | 4.88 (±5.50) | < 0.001 | |
| Control | 4,636 (100) | 464 (10.01) | 4,172 (89.99) | 845 (18.23) | 637 (13.74) | 946 (20.41) | 415 (8.95) | 1,329 (28.67) | 3.49 (±3.92) | ||
| Never smokers (%) | |||||||||||
| Case | 1,103 (100) | 172 (15.59) | 931 (84.41) | 173 (15.68) | 248 (22.48) | 102 (9.25) | 144 (13.06) | 264 (23.93) | 3.11 (±3.14) | < 0.001 | |
| Control | 6,186 (100) | 1,052 (17.01) | 5,134 (82.99) | 924 (14.94) | 1,120 (18.11) | 822 (13.29) | 783 (12.66) | 1, 485 (24.01) | 3.01 (±2.84) | ||
n number, SD standard deviation
a
Calculated by χ2 test for categorical variables and t test for continuous variables
p values < 0.05 were considered statistically significant
p interaction < 0.10 were considered statistically significant