The study has several strengths: the completeness, coverage, and representativeness of the data analysed; the application of an objective, standardised method to determine an admission as having severe sepsis; the ability to adjust extensively for case mix; and the adjustment for clustering of patients' outcomes.
The use of a phosphate binder more than 30 minutes after eating foods rich in phosphorus (always or almost always compared with rarely or never) was significantly associated with phosphate binder non-adherence in both the minimally adjusted model (OR, 5.98; 95% confidence interval (CI), 2.03-17.58) and the extensively adjusted model(OR, 6.15; 95% CI, 2.04-18.50).
All statistical models were extensively adjusted for confounders, including comorbidity, admission diagnosis, other electrolytes and acid base parameters.
We adjusted these parameters extensively but arrived at similar distributions for each experiment.
In the extensively adjusted model, greater odds of non-adherence were observed for patients with higher PTH levels and cerebrovascular disease.
In addition, although we have extensively adjusted for cardiovascular risk factors including physical activity, and, in the case of 25(OH)D3 for seasonal variation, residual confounding may still have occurred.
There was no association between having a dietitian explain PB use (yes versus no) and phosphate binder non-adherence in the minimally (OR, 0.96; 95% CI, 0.62-1.47) or extensively adjusted logistic regression models (OR, 1.11; 95% CI, 0.69-1.79).
More years on dialysis and serum phosphorus >5.5 mg/dL (compared to 3.5-5.5 3.5-5.5were associated with lower odds of non-adherence to the phosphate binder in both the mg/dLally and extensively adjusted logistic regression models.
The extensively adjusted multivariate analysis showed that phosphorus levels greater than 5.5 mg/dL, compared with levels in the range of 3.5-5.5 3.5-5.5were associated with adherence to phosphate binders.
Table 3 shows the minimally and extensively adjusted logistic regressions for the association of the odds of non-adherence to the phosphate binder with the factors deemed potentially modifiable, i.e., the patient's understanding of PB use, the patient's beliefs about PBs, not having the medication, interactions between patients and their families and interactions between patients and the staff.
