Cups of coffee a day | Number of subjects examined | RF positive RA | RF negative RA | RA in total | |||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Number of cases | Relative risk | 95% CI | Number of cases | Relative risk | 95% CI | Number of cases | Relative risk | 95% CI | |||||
0 | 996 | 1 | 1.00 | 1 | 1.00 | 2 | 1.00 | ||||||
1 | 564 | 0 | Indeterminate | 3 | 5.46 | 0.57 to 52.59 | 3 | 2.72 | 0.45 to 16.29 | ||||
2 | 1438 | 4 | 2.75 | 0.31 to 24.60 | 3 | 2.02 | 0.21 to 19.45 | 7 | 2.39 | 0.50 to 11.52 | |||
3 | 1643 | 5 | 2.84 | 0.33 to 24.35 | 1 | 0.54 | 0.03 to 8.68 | 6 | 1.68 | 0.34 to 8.35 | |||
4 | 2994 | 13 | 3.87 | 0.51 to 29.64 | 5 | 1.39 | 0.16 to 11.90 | 18 | 2.63 | 0.61 to 11.33 | |||
5 | 2383 | 18 | 6.82 | 0.91 to 51.13 | 5 | 1.79 | 0.21 to 15.39 | 23 | 4.29 | 1.01 to 18.21 | |||
6 | 4157 | 20 | 4.24 | 0.57 to 31.65 | 9 | 1.79 | 0.23 to 14.20 | 29 | 3.02 | 0.72 to 12.67 | |||
7 | 783 | 4 | 4.62 | 0.52 to 41.40 | 1 | 1.11 | 0.07 to 17.82 | 5 | 2.86 | 0.55 to 14.75 | |||
8 | 1686 | 12 | 6.48 | 0.84 to 49.84 | 5 | 2.63 | 0.31 to 22.53 | 17 | 4.55 | 1.05 to 19.72 | |||
9 | 260 | 2 | 6.70 | 0.61 to 73.97 | 1 | 3.15 | 0.20 to 50.58 | 3 | 4.93 | 0.82 to 29.57 | |||
10 | 1611 | 10 | 6.07 | 0.78 to 47.39 | 3 | 1.83 | 0.19 to 17.62 | 13 | 3.95 | 0.89 to 17.51 | |||
⩾11 | 466 | 0 | Indeterminate | 0 | Indeterminate | 0 | Indeterminate | ||||||
p Value for trend3-150 | 0.02 | 0.88 | 0.04 | ||||||||||
p Value for departure from linearity3-150 | 0.02 | 0.92 | 0.07 |
↵3-150 Likelihood ratio test based on Cox model.