Faculty Bibliography

Strict control of systolic blood pressure is known to slow progression of chronic kidney disease (CKD). Here we compared audit-based education (ABE) to guidelines and prompts or usual practice in lowering systolic blood pressure in people with CKD. This 2-year cluster randomized trial included 93 volunteer general practices randomized into three arms with 30 ABE practices, 32 with guidelines and prompts, and 31 usual practices. An intervention effect on the primary outcome, systolic blood pressure, was calculated using a multilevel model to predict changes after the intervention. The prevalence of CKD was 7.29% (41,183 of 565,016 patients) with all cardiovascular comorbidities more common in those with CKD. Our models showed that the systolic blood pressure was significantly lowered by 2.41 mm Hg (CI 0.59-4.29 mm Hg), in the ABE practices with an odds ratio of achieving at least a 5 mm Hg reduction in systolic blood pressure of 1.24 (CI 1.05-1.45). Practices exposed to guidelines and prompts produced no significant change compared to usual practice. Male gender, ABE, ischemic heart disease, and congestive heart failure were independently associated with a greater lowering of systolic blood pressure but the converse applied to hypertension and age over 75 years. There were no reports of harm. Thus, individuals receiving ABE are more likely to achieve a lower blood pressure than those receiving only usual practice. The findings should be interpreted with caution due to the wide confidence intervals.

Using data for every elective procedure in 2007 in the English National Health Service, we found evidence of socioeconomic inequality in the probability of having a procedure cancelled after admission while controlling for a range of patient and provider characteristics. Whether this disparity is inequitable is inconclusive.

BACKGROUND: 'Failure to rescue'--death after a treatable complication--is used as a nursing sensitive quality indicator in the USA. It is associated with the size of the nursing workforce relative to patient load, for example patient to nurse ratio, although assessments of nurse sensitivity have not previously considered other staff groups. This study aims to assess the potential to derive failure to rescue and a proxy measure, based on long length of stay, from English hospital administrative data. By exploring change in coding practice over time and measuring associations between failure to rescue and factors including staffing, we assess whether two measures of failure to rescue are useful nurse sensitive indicators. DESIGN: Cross sectional observational study of routinely collected administrative data. PARTICIPANTS: Discharge data from 66,100,672 surgical admissions to 146 general acute hospital trusts in England (1997-2009). RESULTS: Median percentage of surgical admissions with at least one secondary diagnosis recorded increased from 26% in 1997/1998 to 40% in 2008/2009. Regression analyses showed that mortality based failure to rescue rates were significantly associated (P<0.05) with several hospital characteristics previously associated with quality, including staffing levels. Lower rates of failure to rescue were associated with a greater number of nurses per bed and doctors per bed in a bivariate analysis. Higher total clinically qualified staffing (doctors+nurses) per bed and a higher number of doctors relative to the number of nurses were both associated with lower mortality based failure to rescue in the fully adjusted analysis (P<0.05); however, the extended stay based measure showed the opposite relationship. CONCLUSION: Failure to rescue can be derived from English administrative data and may be a valid quality indicator. This is the first study to assess the association between failure to rescue and medical staffing. The suggestion that it is particularly sensitive to nursing is not clearly supported, nor is the suggestion that the number of patients with an extended hospital stay is a good proxy.

BACKGROUND: Serum phosphate is a known risk factor for cardiovascular events and mortality in people with chronic kidney disease (CKD), however data on the association of these outcomes with serum phosphate in the general population are scarce. We investigate this relationship in people with and without CKD in a large community-based population. METHODS: Three groups from an adult cohort of the Quality Improvement in Chronic Kidney Disease (QICKD) cluster randomised trial (ISRCTN56023731) were followed over a period of 2.5 years: people with normal renal function (N = 24,184), people with CKD stages 1-2 (N = 20,356), and people with CKD stages 3-5 (N = 13,292). We used a multilevel logistic regression model to determine the association between serum phosphate, in these groups, and a composite outcome of all-cause mortality, cardiovascular events, and advanced coronary artery disease. We adjusted for known cardiovascular risk factors. FINDINGS: Higher phosphate levels were found to correlate with increased cardiovascular risk. In people with normal renal function and CKD stages 1-2, Phosphate levels between 1.25 and 1.50 mmol/l were associated with increased cardiovascular events; odds ratio (OR) 1.36 (95% CI 1.06-1.74; p = 0.016) in people with normal renal function and OR 1.40 (95% CI 1.09-1.81; p = 0.010) in people with CKD stages 1-2. Hypophosphatemia (<0.75 mmol/l) was associated with fewer cardiovascular events in people with normal renal function; OR 0.59 (95% CI 0.36-0.97; p = 0.049). In people with CKD stages 3-5, hyperphosphatemia (>1.50 mmol/l) was associated with increased cardiovascular risk; OR 2.34 (95% CI 1.64-3.32; p<0.001). Other phosphate ranges were not found to have a significant impact on cardiovascular events in people with CKD stages 3-5. CONCLUSIONS: Serum phosphate is associated with cardiovascular events in people with and without CKD. Further research is required to determine the mechanisms underlying these associations.

BACKGROUND: Most chronic diseases are managed in primary and ambulatory care. The chronic care model (CCM) suggests a wide range of community, technological, team and patient factors contribute to effective chronic disease management. Ontologies have the capability to enable formalised linkage of heterogeneous data sources as might be found across the elements of the CCM. OBJECTIVE: To describe the evidence base for using ontologies and other semantic integration methods to support chronic disease management. METHOD: We reviewed the evidence-base for the use of ontologies and other semantic integration methods within and across the elements of the CCM. We report them using a realist review describing the context in which the mechanism was applied, and any outcome measures. RESULTS: Most evidence was descriptive with an almost complete absence of empirical research and important gaps in the evidence-base. We found some use of ontologies and semantic integration methods for community support of the medical home and for care in the community. Ubiquitous information technology (IT) and other IT tools were deployed to support self-management support, use of shared registries, health behavioural models and knowledge discovery tools to improve delivery system design. Data quality issues restricted the use of clinical data; however there was an increased use of interoperable data and health system integration. CONCLUSIONS: Ontologies and semantic integration methods are emergent with limited evidence-base for their implementation. However, they have the potential to integrate the disparate community wide data sources to provide the information necessary for effective chronic disease management.