| Case/ Total | Incidence rate, per 1000 person-years | Model 1 | Model 2 | Model 3 |
---|---|---|---|---|---|
Quartiles | |||||
 Q1 | 312/13524 | 2.56 | 1.00 | 1.00 | 1.00 |
 Q2 | 435/13525 | 3.66 | 1.24 (1.07,1.44) | 1.14 (0.98,1.32) | 1.09 (0.94,1.27) |
 Q3 | 604/13525 | 5.24 | 1.53 (1.33,1.76) | 1.34 (1.17,1.55) | 1.26 (1.09,1.45) |
 Q4 | 732/13524 | 6.68 | 1.79 (1.56,2.05) | 1.45 (1.25,1.67) | 1.30 (1.12,1.52) |
 P for Trend |  |  |  < 0.0001 |  < 0.0001 | 0.0002 |
Time exposure duration | Â | Â | |||
 0 year | 365/14630 | 2.89 | 1.00 | 1.00 | 1.00 |
 2 years | 415/12653 | 3.79 | 1.37 (1.19,1.57) | 1.22 (1.06,1.40) | 1.18 (1.02,1.36) |
 4 years | 501/11733 | 4.95 | 1.77 (1.54,2.02) | 1.42 (1.23,1.63) | 1.32 (1.14,1.54) |
 6 years | 802/15082 | 6.26 | 2.18 (1.92,2.47) | 1.57 (1.37,1.80) | 1.38 (1.16,1.64) |
 P for Trend |  |  |  < 0.0001 |  < 0.0001 | 0.0003 |