Table 4.
Multivariate hazard ratios for nutritional indices and intakes for all-cause mortality
(Hazard ratios and 95% confidence intervals)
| Hazard ratios (per SD) | 95%CI | P | Hazard ratios (per SD) | 95%CI | P | |
|---|---|---|---|---|---|---|
| Model (a): died n 717, alive n 357* |
Model (b): died n 482, alive n 242 |
|||||
| Plasma Se (μmol/l) | 0·76 | 0·69, 0·84 | <0·001 | 0·82 | 0·73, 0·91 | <0·001 |
| Plasma Zn (μmol/l) | 0·79 | 0·72, 0·87 | <0·001 | 0·84 | 0·76, 0·93 | 0·001 |
| Plasma Cu (μmol/l) | 1·27 | 1·14, 1·42 | <0·001 | 1·20 | 1·07, 1·34 | 0·002 |
| Plasma Fe (μmol/l) | 0·81 | 0·74, 0·89 | <0·001 | 0·87 | 0·78, 0·96 | 0·005 |
| Dietary energy (MJ/d) | 0·86 | 0·79, 0·94 | 0·001 | 0·86 | 0·77, 0·96 | 0·007 |
| Model (c): died n 472, alive n 241 | Model (d): died n 403, alive n 226 | |||||
| Plasma Se (μmol/l) | 0·82 | 0·74, 0·92 | 0·001 | 0·83 | 0·73, 0·94 | 0·004 |
| Plasma Zn (μmol/l) | 0·88 | 0·79, 0·98 | 0·017 | 0·86 | 0·76, 0·97 | 0·017 |
| Plasma Cu (μmol/l) | 1·08 | 0·94, 1·22 | 0·3 | 1·02 | 0·88, 1·18 | 0·8 |
| Plasma Fe (μmol/l) | 0·87 | 0·78, 0·96 | 0·005 | 0·94 | 0·84, 1·05 | 0·3 |
| Dietary energy (MJ/d) | 0·87 | 0·77, 0·98 | 0·027 | 0·87 | 0·77, 0·98 | 0·03 |
As explained in the legend to Table 1, these were the study maximum values for n (i.e. those for the dietary variables); the values for the biochemical indices were lower, see Table 1. These models, for all-cause mortality, follow on from the left-hand data column in Table 2. For the calculations in part (a), each single (nutrient) variable was entered into the Cox proportional hazards model, together with age and sex (as in Tables 2 and 3). For those in part (b), all of the significant (P<0·05) vitamin or mineral predictor variables from Table 3, plus age and sex, were initially included together in the model; then those which fell below the assigned P<0·05 significance cut-off were successively removed, yielding just the significantly predictive nutrient variables in this multivariate model. For the calculations for the models in part (c), the significantly predictive vitamin or mineral indices or intakes from model (b) were further adjusted by the inclusion of a1-antichymotrypsin (an acute-phase indicator), plasma creatinine (a renal status indicator), plasma total and HDL-cholesterol concentrations and plasma albumin concentration. For the calculations in model (d), BMI, systolic blood pressure, current smoking index, number of prescribed drugs being taken, self-reported health score, physical activity score and receipt (or not) of certain state benefits (as an index of poverty) were further added to the variables in model (c).