Association between practice coding of chronic kidney disease (CKD) in primary care and subsequent hospitalisations and death: a cohort analysis using national audit data.

OBJECTIVE: To examine the association between practice percentage coding of chronic kidney disease (CKD) in primary care with risk of subsequent hospitalisations and death. DESIGN: Retrospective cohort study using linked electronic healthcare records. SETTING: 637 general practitioner (GP) practices in England. PARTICIPANTS: 167 208 patients with CKD stages 3-5 identified by 2 measures of estimated glomerular filtration rate <60 mL/min/1.73 m2, separated by at least 90 days, excluding those with coded initiation of renal replacement therapy. MAIN OUTCOME MEASURES: Hospitalisations with cardiovascular (CV) events, heart failure (HF), acute kidney injury (AKI) and all-cause mortality RESULTS: Participants were followed for (median) 3.8 years for hospital outcomes and 4.3 years for deaths. Rates of hospitalisations with CV events and HF were lower in practices with higher percentage CKD coding. Trends of a small reduction in AKI but no substantial change in rate of deaths were also observed as CKD coding increased. Compared with patients in the median performing practice (74% coded), patients in practices coding 55% of CKD cases had a higher rate of CV hospitalisations (HR 1.061 (95% CI 1.015 to 1.109)) and HF hospitalisations (HR 1.097 (95% CI 1.013 to 1.187)) and patients in practices coding 88% of CKD cases had a reduced rate of CV hospitalisations (HR 0.957 (95% CI 0.920 to 0.996)) and HF hospitalisations (HR 0.918 (95% CI 0.855 to 0.985)). We estimate that 9.0% of CV hospitalisations and 16.0% of HF hospitalisations could be prevented by improving practice CKD coding from 55% to 88%. Prescription of antihypertensives was the most dominant predictor of a reduction in hospitalisation rates for patients with CKD, followed by albuminuria testing and use of statins. CONCLUSIONS: Higher levels of CKD coding by GP practices were associated with lower rates of CV and HF events, which may be driven by increased use of antihypertensives and regular albuminuria testing, although residual confounding cannot be ruled out.

Aspirin to target arterial events in chronic kidney disease (ATTACK): study protocol for a multicentre, prospective, randomised, open-label, blinded endpoint, parallel group trial of low-dose aspirin vs. standard care for the primary prevention of cardiovascular disease in people with chronic kidney disease.

BACKGROUND: Chronic kidney disease (CKD) is a very common long-term condition and powerful risk factor for cardiovascular disease (CVD). Low-dose aspirin is of proven benefit in the secondary prevention of myocardial infarction (MI) and stroke in people with pre-existing CVD. However, in people without CVD, the rates of MI and stroke are much lower, and the benefits of aspirin in the primary prevention of CVD are largely balanced by an increased risk of bleeding. People with CKD are at greatly increased risk of CVD and so the absolute benefits of aspirin are likely to be greater than in lower-risk groups, even if the relative benefits are the same. Post hoc evidence suggests the relative benefits may be greater in the CKD population but the risk of bleeding may also be higher. A definitive study of aspirin for primary prevention in this high-risk group, recommended by the National Institute for Health and Care Excellence (NICE) in 2014, has never been conducted. The question has global significance given the rising burden of CKD worldwide and the low cost of aspirin. METHODS: ATTACK is a pragmatic multicentre, prospective, randomised, open-label, blinded endpoint adjudication superiority trial of aspirin 75 mg daily vs. standard care for the primary prevention of CVD in 25,210 people aged 18 years and over with CKD recruited from UK Primary Care. Participants aged 18 years and over with CKD (GFR category G1-G4) will be identified in Primary Care and followed up using routinely collected data and annual questionnaires for an average of 5 years. The primary outcome is the time to first major vascular event (composite of non-fatal MI, non-fatal stroke and cardiovascular death [excluding confirmed intracranial haemorrhage and other fatal cardiovascular haemorrhage]). Deaths from other causes (including fatal bleeding) will be treated as competing events. The study will continue until 1827 major vascular events have occurred. The principal safety outcome is major intracranial and extracranial bleeding; this is hypothesised to be increased in those randomised to take aspirin. The key consideration is then whether and to what extent the benefits of aspirin from the expected reduction in CVD events exceed the risks of major bleeding. DISCUSSION: This will be the first definitive trial of aspirin for primary CVD prevention in CKD patients. The research will be of great interest to clinicians, guideline groups and policy-makers, in the UK and globally, particularly given the high and rising prevalence of CKD that is driven by population ageing and epidemics of obesity and diabetes. The low cost of aspirin means that a positive result would be of relevance to low- and middle-income countries and the impact in the developed world less diluted by any inequalities in health care access. TRIAL REGISTRATION: ISRCTN: ISRCTN40920200 . EudraCT: 2018-000644-26 . CLINICALTRIALS: gov: NCT03796156.

Accounting for overdispersion when determining primary care outliers for the identification of chronic kidney disease: learning from the National Chronic Kidney Disease Audit.

Background: Early diagnosis of chronic kidney disease (CKD) facilitates best management in primary care. Testing coverage of those at risk and translation into subsequent diagnostic coding will impact on observed CKD prevalence. Using initial data from 915 general practitioner (GP) practices taking part in a UK national audit, we seek to apply appropriate methods to identify outlying practices in terms of CKD stages 3-5 prevalence and diagnostic coding. Methods: We estimate expected numbers of CKD stages 3-5 cases in each practice, adjusted for key practice characteristics, and further inflate the control limits to account for overdispersion related to unobserved factors (including unobserved risk factors for CKD, and between-practice differences in coding and testing). Results: GP practice prevalence of coded CKD stages 3-5 ranges from 0.04 to 7.8%. Practices differ considerably in coding of CKD in individuals where CKD is indicated following testing (ranging from 0 to 97% of those with and glomerular filtration rate <60 mL/min/1.73 m 2 ). After adjusting for risk factors and overdispersion, the number of 'extreme' practices is reduced from 29 to 2.6% for the low-coded CKD prevalence outcome, from 21 to 1% for high-uncoded CKD stage and from 22 to 2.4% for low total (coded and uncoded) CKD prevalence. Thirty-one practices are identified as outliers for at least one of these outcomes. These can then be categorized into practices needing to address testing, coding or data storage/transfer issues. Conclusions: GP practice prevalence of coded CKD shows wide variation. Accounting for overdispersion is crucial in providing useful information about outlying practices for CKD prevalence.

Development of guidance on the timeliness in response to acute kidney injury warning stage test results for adults in primary care: an appropriateness ratings evaluation.

OBJECTIVES: Tackling the harm associated with acute kidney injury (AKI) is a global priority. In England, a national computerised AKI algorithm is being introduced across the National Health Service (NHS) to drive this change. The study sought to maximise its clinical utility and minimise the potential for burden on clinicians and patients in primary care. DESIGN: An appropriateness ratings evaluation using the RAND/UCLA Appropriateness Method. SETTING: Clinical scenarios were developed to test the timeliness in (1) communication of AKI warning stage test results from clinical pathology services to primary care, and (2) primary care clinician response to an AKI warning stage test result. PARTICIPANTS: A 10-person panel was purposively sampled with representation from clinical biochemistry, acute and emergency medicine and general practice. General practitioners (GPs) represented typical practice in relation to rural and urban practice, out of hours care, GP commissioning and those interested in reducing the impact of medicalisation and 'overdiagnosis'. RESULTS: There was agreement that delivery of AKI warning stage test results through interruptive methods of communication (ie, telephone) from laboratories to primary care was the appropriate next step for patients with an AKI warning stage 3 test result. In the context of acute illness, waiting up to 72 hours to respond to an AKI warning stage test result was deemed an inappropriate action in 62 out of the 65 (94.5%) cases. There was agreement that a clinician response was required within 6 hours, or less, in 39 out of 40 (97.5%) clinical cases relating AKI warning stage test results in the presence of moderate hyperkalaemia. CONCLUSIONS: The study has informed national guidance to support a timely and calibrated response to AKI warning stage test results for adults in primary care. Further research is needed to support effective implementation, with a view to examine the effect on health outcomes and costs.