Table 3.
Pooled hazard ratios (95% CI) for incident RA according to cumulative AHEI-2010 quartile in Nurses’ Health Study (NHS, 1984–2012) and Nurses’ Health Study II (NHS II, 1991–2013) stratified by age before or after 55 years
| AHEI Score, quartile
|
|||||
|---|---|---|---|---|---|
| Q1 | Q2 | Q3 | Q4 | p for trend ‡ | |
| Age ≤55 years | |||||
|
| |||||
| All RA | |||||
| Case/person-years | 136/558,968 | 125/535,171 | 99/513,734 | 84/485,162 | |
| Age adjusted model 1 | 1.00 | 0.90(0.70 to 1.15) | 0.76(0.58 to 0.98) | 0.68(0.52 to 0.89) | 0.003 |
| Multivariable model 2 (main)* | 1.00 | 0.89(0.69 to 1.14) | 0.75(0.57 to 0.97) | 0.67(0.51 to 0.88) | 0.002 |
| Multivariable model 3† | 1.00 | 0.90(0.70 to 1.15) | 0.76(0.59 to 1.00) | 0.71(0.54 to 0.94) | 0.009 |
|
| |||||
| Seropositive RA | |||||
| Case/person-years | 87/548,349 | 83/525,054 | 70/503,397 | 47/476,102 | |
| Age adjusted model 1 | 1.00 | 0.95(0.70 to 1.29) | 0.81(0.58 to 1.11) | 0.63(0.44 to 0.89) | 0.005 |
| Multivariable model 2 (main)* | 1.00 | 0.93(0.68 to 1.27) | 0.78(0.57 to 1.09) | 0.60(0.42 to 0.86) | 0.003 |
| Multivariable model 3† | 1.00 | 0.95(0.69 to 1.28) | 0.81(0.58 to 1.12) | 0.65(0.45 to 0.92) | 0.011 |
|
| |||||
| Seronegative RA | |||||
| Case/person-years | 49/556,795 | 42/533,240 | 29/511,879 | 37/483,609 | |
| Age adjusted model 1 | 1.00 | 0.80(0.52 to 1.23) | 0.67(0.43 to 1.05) | 0.77(0.50 to 1.18) | 0.18 |
| Multivariable model 2 (main)* | 1.00 | 0.81(0.52 to 1.24) | 0.68(0.43 to 1.07) | 0.79(0.51 to 1.24) | 0.26 |
| Multivariable model 3† | 1.00 | 0.81(0.52 to 1.24) | 0.69(0.44 to 1.09) | 0.83(0.53 to 1.29) | 0.34 |
|
| |||||
| Age>55 years | |||||
|
| |||||
| All RA | |||||
| Case/person-years | 116/365,249 | 136/390,708 | 156/412,404 | 154/440,769 | |
| Age adjusted model 1 | 1.00 | 1.08(0.85 to 1.37) | 1.10(0.87 to 1.40) | 1.11(0.87 to 1.41) | 0.39 |
| Multivariable model 2 (main)* | 1.00 | 1.08(0.85 to 1.37) | 1.10(0.86 to 1.40) | 1.10(0.86 to 1.41) | 0.45 |
| Multivariable model 3† | 1.00 | 1.08(0.85 to 1.37) | 1.10(0.87 to 1.41) | 1.11(0.87 to 1.42) | 0.40 |
|
| |||||
| Seropositive RA | |||||
| Case/person-years | 68/363,288 | 78/388,184 | 90/409,690 | 101/438,302 | |
| Age adjusted model 1 | 1.00 | 1.04(0.76 to 1.42) | 1.13(0.83 to 1.54) | 1.19(0.88 to 1.62) | 0.21 |
| Multivariable model 2 (main)* | 1.00 | 1.06(0.77 to 1.45) | 1.17(0.85 to 1.59) | 1.22(0.89 to 1.68) | 0.17 |
| Multivariable model 3† | 1.00 | 1.06(0.77 to 1.45) | 1.17(0.85 to 1.60) | 1.23(0.90 to 1.69) | 0.16 |
|
| |||||
| Seronegative RA | |||||
| Case/person-years | 48/364,396 | 58/389,885 | 66/411,265 | 53/439,561 | |
| Age adjusted model | 1.00 | 1.13(0.78 to 1.64) | 1.07(0.73 to 1.56) | 0.99(0.67 to 1.45) | 0.87 |
| Multivariable model 1 (main)* | 1.00 | 1.09(0.75 to 1.58) | 1.01(0.69 to 1.48) | 0.91(0.62 to 1.36) | 0.57 |
| Multivariable model 2† | 1.00 | 1.09(0.75 to 1.58) | 1.02(0.69 to 1.49) | 0.93(0.63 to 1.39) | 0.66 |
Hazard ratios were calculated by using time-varying Cox proportional hazards models
Adjustment for age, cohort, smoking (never, past, current 1–14 cigarettes/d, current ≥15 cigarettes/d), age at menarche (<12, 12, >12 years), parity and breast feeding (nulliparous, parous/no breastfeeding, parous/1–12 months breastfeeding, parous/ >12 months breastfeeding), hormone use (pre-menopausal, post-menopausal with never use, current use and past use) and total energy (quintiles)
Additional adjustment for BMI (<20, 20–22.9, 23–24.9, 25–29.9, ≥30kg/m2)
p for trend was derived from tests of linear trend across categories of AHEI scores by treating the median value of each category as a continuous variable