| Summary: | The UK Renal Registry has published dialysis centre comparisons of performance against audit measures specified in national clinical practice guidelines for over ten years. There has never previously been any research to identify possible causes for the underlying differences observed in centre performance against these audit measures. The overall aim of this thesis was to determine whether it is possible to identify characteristics of dialysis centres (both related to organisational structure and clinical processes) which were associated with better outcomes against audit measures for calcium, phosphate and parathyroid hormone. The clinical practice guidelines for calcium, phosphate and parathyroid hormone are supported by observational data that hyperphosphataemia and possibly hypercalcaemia are associated with increased mortality in dialysis cohorts. This thesis studied this relationship in a prevalent UK haemodialysis cohort and demonstrated increased mortality was associated with hyperphosphataemia when data were adjusted for case-mix. There was also an association with hypercalcaemia but this may be a threshold effect. This study provided some justification for the subsequent study looking at organisational characteristics associated with outcomes for calcium, phosphate and parathyroid hormone. A methodological study is then presented discussing the merits of different type of performance analysis and presentation of these data using UK Renal Registry data as an example. A survey was designed, piloted and circulated to dialysis centres in England, Wales and Northern Ireland to identify structural characteristics, organisational and clinical processes which might be associated with better performance against the audit measures for calcium, phosphate and parathyroid hormone. These explanatory variables were analysed in case-mix adjusted multilevel statistical models. The study identified organisational variables which were associated with better performance for each of the outcome variables; better phosphate results were associated with a system of care which provided consistency for patient review and quality assurance; better calcium results associated with protocol or unrestricted use of certain specialist drugs (lanthanum) and better parathyroid hormone results associated with increased numbers of dieticians and surgeons able to undertake parathyroidectomy.
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