Table 4.
Association between night shift work and CVD-specific (>100 deaths) mortality in NHS, 1988-2010 (n=74,862).
| Night shift work duration |
|||||
|---|---|---|---|---|---|
| Mortality | Never | 1–5 years | 6–14 years | ≥15 years | p for trend |
| Ischaemic heart disease | |||||
| No. of deaths | 407 | 386 | 170 | 153 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.92 (0.80, 1.05) | 1.38 (1.15, 1.65) | 1.69 (1.40, 2.04) | <0.001 |
| Multivariable HR (95% CI)a | 1.00 (ref) | 0.97 (0.85, 1.12) | 1.23 (1.03, 1.47) | 1.34 (1.11, 1.61) | <0.001 |
| Multivariable HR (95% CI)b | 1.00 (ref) | 0.96 (0.83, 1.11) | 1.17 (0.98, 1.41) | 1.23 (1.02, 1.49) | 0.006 |
| Cerebrovascular disease | |||||
| No. of deaths | 319 | 320 | 119 | 90 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 0.97 (0.83, 1.14) | 1.24 (1.00, 1.53) | 1.23 (0.97, 1.55) | 0.02 |
| Multivariable HR (95% CI)a | 1.00 (ref) | 1.02 (0.87, 1.20) | 1.20 (0.97, 1.48) | 1.12 (0.88, 1.42) | 0.17 |
| Multivariable HR (95% CI)b | 1.00 (ref) | 1.01 (0.86, 1.18) | 1.16 (0.94, 1.44) | 1.06 (0.83, 1.34) | 0.36 |
| Other cardiovascular disease | |||||
| No. of deaths | 402 | 422 | 153 | 121 | |
| Age-adjusted HR (95% CI) | 1.00 (ref) | 1.02 (0.89, 1.16) | 1.28 (1.06, 1.54) | 1.36 (1.11, 1.67) | <0.001 |
| Multivariable HR (95% CI)a | 1.00 (ref) | 1.05 (0.91, 1.20) | 1.18 (0.97, 1.42) | 1.17 (0.95, 1.44) | 0.06 |
| Multivariable HR (95% CI)b | 1.00 (ref) | 1.04 (0.90, 1.19) | 1.14 (0.94, 1.38) | 1.13 (0.92, 1.39) | 0.14 |
Boldface indicates statistical significance (p<0.05).
HR, hazard ratio; NHS, Nurses’ Health Study; CVD, Cardiovascular diseases
Multivariable model adjusted for age (continuous), alcohol consumption (none, 0.1-4.9, 5.0-14.9, ≥15.0 g/d), physical exercise (metabolic equivalent values; quintiles), multivitamin use (yes, no), menopausal status (premenopausal, postmenopausal) and postmenopausal hormone use (never, past and current), physical exam in the past 2 years (no , yes for symptoms and yes for screenings), healthy eating score (quintiles), smoking status (never, former, current), pack-years (<10, 10-19, 20-39, ≥40 for former smokers; <25, 25-44, 45-64, ≥65 for current smokers), BMI (kg/m2; <21, 21-22.9, 23-24.9, 25-27.4, 27.5-29.9, 30-34.9, ≥35) and husband’s education (less than high school, some high school, high school graduate, college, graduate school, missingness).
This model was further adjusted for hypertension (yes, no), hypercholesterolemia (yes, no), type 2 diabetes (yes, no),