Table 3.
All-cause mortality among participants with inflammatory bowel disease according to lifestyle factors
| Variables | Inflammatory bowel disease | |||
|---|---|---|---|---|
| Person-years | No. of deaths | Age-adjusted HR (95% CI)a | Multivariable-adjusted HR (95% CI)b | |
| Smoking status | ||||
| Never smoker | 5321 | 54 | 1 (reference) | 1 (reference) |
| Past smoker | 4710 | 87 | 1.25 (0.86–1.83) | 1.25 (0.83–1.87) |
| Current smoker | 772 | 22 | 3.89 (2.27–6.68) | 4.08 (2.28–7.30) |
| Pack-years of smoking | ||||
| Never smoker | 5077 | 47 | 1 (reference) | 1 (reference) |
| ≤10 | 1698 | 14 | 1.00 (0.54–1.86) | 1.06 (0.55–2.03) |
| 10.1–25 | 2006 | 34 | 1.48 (0.91–2.42) | 1.45 (0.86–2.45) |
| >25 | 2022 | 68 | 1.92 (1.26–2.91) | 1.92 (1.24–2.97) |
| P for trendc | <0.0001 | <0.0001 | ||
| Body mass index | ||||
| <18.5 kg/m2 | 171 | 5 | 1.38 (0.54–3.52) | 1.66 (0.62–4.47) |
| 18.5–24.9 kg/m2 | 5314 | 71 | 1 (reference) | 1 (reference) |
| 25–29.9 kg/m2 | 3303 | 55 | 1.03 (0.70–1.53) | 1.10 (0.73–1.67) |
| ≥30 kg/m2 | 2015 | 32 | 1.52 (0.97–2.37) | 1.64 (1.03–2.63) |
| P for trend <25 kg/m2c | 0.12 | 0.08 | ||
| P for trend ≥18.5 kg/m2c | 0.04 | 0.08 | ||
| Physical activity | ||||
| Quintile 1 | 2120 | 49 | 1 (reference) | 1 (reference) |
| Quintile 2 | 2034 | 34 | 0.56 (0.35–0.90) | 0.55 (0.33–0.92) |
| Quintile 3 | 2326 | 38 | 0.45 (0.28–0.73) | 0.43 (0.26–0.71) |
| Quintile 4 | 2182 | 22 | 0.33 (0.19–0.57) | 0.31 (0.17–0.57) |
| Quintile 5 | 2041 | 20 | 0.41 (0.23–0.74) | 0.35 (0.19–0.65) |
| P for trendd | 0.003 | 0.001 | ||
| Alternate Mediterranean diet score | ||||
| <4 | 4776 | 87 | 1 (reference) | 1 (reference) |
| ≥4 | 6027 | 76 | 0.66 (0.47–0.93) | 0.69 (0.49–0.98) |
| P | 0.02 | 0.04 | ||
| Alcohol consumption | ||||
| Nondrinker | 4751 | 78 | 1 (reference) | 1 (reference) |
| 0.1–5 g/d | 3363 | 38 | 0.63 (0.41–0.97) | 0.61 (0.39–0.95) |
| 5.1–15 g/d | 1727 | 26 | 0.85 (0.53–1.37) | 1.08 (0.65–1.81) |
| >15 g/d | 962 | 21 | 1.34 (0.78–2.30) | 1.84 (1.02–3.32) |
| P for trend ≤5 g/dc | 0.07 | 0.03 | ||
| P for trend >0 g/dc | 0.0004 | 0.0003 | ||
Abbreviations: NHS, Nurses’ Health Study; HPFS, Health Professionals Follow-up Study; HR, hazard ratio; CI, confidence interval; BMI, body mass index; MET, metabolic equivalent of task; aMED, alternate Mediterranean diet score.
Cox proportional hazards regression model stratified by age at diagnosis (in 5-year intervals), year of diagnosis (<1990, 1990–1999, 2000–2009, ≥2010), cohort (NHS, NHS II HPFS), with additional adjustment for age at diagnosis (continuous, year).
Further adjusted for race (Southern European/Mediterranean, Scandinavian, other Caucasian, other races), post-diagnostic smoking status (never smoker, 0.1–10, 10.1–25, >25 pack-years), BMI (<18.5, 18.5–24.9, 25–29.9, ≥30 kg/m2), physical activity (in quintiles, MET-hr/wk), aMED (in quartiles), and alcohol consumption (nondrinker, 0.1–5, 5.1–15, >15 g/d).
P for trend was calculated by treating the exposure as a continuous variable.
P for trend was calculated using the median of each quintile as a continuous variable.