Michael Bedford

The economic impact of acute kidney injury in England

BACKGROUND Acute kidney injury (AKI) is one of the most common complications affecting hospital inpatients around the world. It is associated with high mortality and adverse long-term outcomes, but there is uncertainty regarding its prevalence and cost. We estimate the prevalence of AKI in hospital inpatients in a universal health-care system, and the immediate and long-term impacts on survival, quality of life and health-care costs. METHODS We examined prevalence of AKI in inpatients using both routine national data for the National Health Service (NHS) in England, and laboratory data from East Kent Hospitals. We used regression analyses to estimate the impact of AKI on mortality and length of hospital stay, and a Markov model to estimate the impact on quality-adjusted life years and NHS costs. RESULTS AKI was recorded in 2.43% of hospital admissions in Hospital Episode Statistics (HES), but age- and gender-standardized estimates derived from laboratory data suggest the true prevalence may be more than five times as high (14.15%). We estimate that the annual number of excess inpatient deaths associated with AKI in England may be above 40,000. The annual cost of AKI-related inpatient care in England is estimated at £1.02 billion, just over 1% of the NHS budget. The lifetime cost of post-discharge care for people who had AKI during hospital admission in 2010-11 is estimated at £179 million. CONCLUSIONS AKI prevalence in inpatients may be considerably higher than previously thought, and up to four fifths of cases may not be captured in routine hospital data. AKI is associated with large numbers of in-hospital deaths and with high NHS costs. Comparison of HES and East Kent data suggests that most of the cases recorded in HES may be relatively severe AKI (AKIN 2-3).

Acute kidney injury: an acceptable risk of treatment with renin-angiotensin system blockade in primary care?

BackgroundUse of renin-angiotensin system (RAS) blockade has become increasingly widespread driven by evidence-based guidance. There is concern about the role of these agents in the genesis of avoidable acute kidney injury (AKI).ObjectivesTo investigate the association between AKI and use of RAS blockade.DesignMultilevel hierarchical analysis of a large cohort of patients registered with UK general practitioners.SettingPrimary care practices in East and West Kent, United Kingdom.Patients244,715 patients from 27 practices.MeasurementsDemographic, clinical, biochemical and prescription data.MethodsAnalyses of data acquired between 02/3/2004 and 17/04/2012 using multilevel logistic regression to determine the relationship between AKI and use of RAS blockade; further analysed by indication for treatment with RAS blockade.ResultsSufficient serum creatinine data were available to define AKI in 63,735 patients with 208,275 blood test instances. In 95,569 instances the patient was prescribed a RAS antagonist of which 5.4% fulfilled criteria for AKI. The unadjusted odds ratio (OR) for AKI in those prescribed RAS blockade was 1.93 (1.81-2.06, 95%CI) falling to 1.11 (1.02-1.20, 95%CI) when adjusted for age, gender, co-morbidity, GFR category, proteinuria, systolic blood pressure and diuretic therapy. In patients with an evidence-based indication there was no difference in absolute risk of AKI. However, prescription of RAS blockade in the absence of indication appeared to be associated with greater risk of AKI.When analysis was repeated with AKIN2/AKIN3 as the outcome, although risk of AKI remained significant when unadjusted (OR 1.73, 95%CI 1.42-2.11, p<0.001), after full adjustment there was no increased risk (OR 0.83, 95%CI 0.63-1.09) in those taking RAS antagonists. However, when analysed by indication AKIN2/AKIN3 was significantly more likely in those prescribed RAS antagonists without indication (OR 2.04, 95%CI 1.41-2.94, p<0.001).LimitationsObservational database study. No information concerning hospitalisation. Prescribing assumptions and potential inaccurate coding. Potential survival bias; patients surviving longer will contribute more data.ConclusionsUse of RAS antagonists increased the risk of AKI, independent of common confounding variables. After correction for confounders the risk fell away and became non-significant for moderate and severe AKI. However, where there was no evidence-based indication for RAS antagonists the risk of AKI, whether mild, moderate or severe, remained greater.AbrégéContexteVu l’abondance de données probantes en la matière, le recours aux inhibiteurs du système rénine-angiotensine-aldostérone (SRAA) est de plus en plus répandu. Il existe certaines préoccupations quant au rôle de ces agents dans la genèse de l’insuffisance rénale aiguë (IRA) évitable.Objectif de l’étudeExaminer, au sein d’une cohorte en soins de santé primaires, la présence de liens entre l’IRA et l’utilisation d’inhibiteurs du SRAA.Type d’étudeUne analyse hiérarchique multiniveaux d’une vaste cohorte de patients suivis par des médecins généralistes du Royaume-Uni.ContexteCliniques de soins de santé primaires situées dans l’est et l’ouest du comté du Kent, au Royaume-Uni.PatientsLes données ont été recueillies auprès d’une cohorte de 244 715 patients en soins primaires, provenant de 27 cliniques de soins primaires dans l’est et l’ouest du comté du Kent.MesuresDonnées démographiques, cliniques, biochimiques et issues d’ordonnances.MéthodesL’analyse des données recueillies entre le 2004/03/02 et le 2012/04/17 a été effectuée par régression logistique multiniveaux afin de déterminer la relation entre l’IRA et l’utilisation d’inhibiteurs du SRAA, et ensuite par indication de traitement avec des inhibiteurs du SRAA.RésultatsUne quantité suffisante de données relatives à la créatininémie était disponible pour évaluer l’IRA chez 63 735 patients, qui avaient eu au total 208 275 prélèvements sanguins. Chez 95 569 sujets, un inhibiteur du SRAA a été prescrit, et 5,4% (5 194) de ces derniers ont eu un épisode d’IRA. Chez les patientsrecevant un traitement fondé sur des indications probantes, 5,8% (4473 sur 76 517) ont eu un épisode d’IRA. Le risque relatif non ajusté (RR) d’IRA associé à l’utilisation d’un inhibiteur du SRAA était de 1,93 (1,81-2,06, 95% IC), diminuant à 1,11 (1,02-1,20, 95% IC) lorsqu’ajusté pour l’ âge, le sexe, la comorbidité, la catégorie de débit de filtration glomérulaire, la protéinurie, la pression artérielle systolique et le traitement diurétique. Chez les patients recevant un traitement par inhibiteurs du SRAA fondé sur des indications probantes, il n’y avait aucune différence de risque absolu d’IRA. Par contre, il semblait y avoir un lien entre la prescription d’inhibiteurs du SRAA en l’absence d’indications probantes et un risque accru d’IRA. Lorsque l’analyse a été répétée avec l’AKIN2/AKIN3 comme critère de jugement, le risque d’IRA associé à l’utilisation d’un inhibiteur du SRAA restait significatif dans le modèle non ajusté (RR 1,73, 95% IC 1,42-2,11, p < 0,001), mais aucune augmentation de risque n’a été observée après ajustement (RR 0,83, 95% IC 0,63-1,09). Par contre, le risque d’AKIN2/AKIN3 lié à l’utilisation d’un inhibiteur du SRAA était significativement plus élevée chez les patients qui recevaient ces agents sans indications probantes (RR 2,04, 95% IC, 1,41-2,94, p < 0,001).Limites de l’étudeÉtude par observation de données prises dans des cliniques de soins primaires. Aucune information d’hospitalisation disponible (base de données de soins primaires). Interprétation des prescriptions et possibilité de codes erronés. Biais de temps d’immortalité possible : les patients qui vivent plus longtemps contribuent davantage à l’analyse par les prélèvements sanguins.ConclusionsNotre analyse montre que l’utilisation d’inhibiteurs du SRAA augmente le risque d’IRA. Le risque est indépendant de diverses variables de confusion, dont l’âge, la mesure de base de la fonction rénale, la présence de comorbidité pertinente et la pression artérielle systolique. Après correction pour les variables confusionnelles, le risque diminuait toujours : il devenait non significatif pour l’IRA modérée et sévère. Par contre, le risque d’IRA légere, modérée ou sévère demeurait élevé lorsque l’utilisation d’inhibiteurs du SRAA ne s’appuyait sur aucune indication probante.Renin angiotensin system blockade is known to be associated with acute kidney injury. This is the first study to examine this association by evidence-based indication. Although renin angiotensin system blockade increases the risk of acute kidney injury overall, in those with an evidence-based indication the majority of the effect is explained by underlying co-morbidity. In people with no evidence-based indication prescription of renin angiotensin blockade is an independent predictor of acute kidney injury.

Directing specialist care through email admission alerting

ABSTRACT Unscheduled care is complex, particularly because many patients have multiple long term medical conditions. It is difficult to ensure the appropriate care is delivered by specialist services to patients in a timely manner. Lack of specialist input may impact on patient safety and adversely affect outcomes. We describe an automated email alerting system which was developed as result of a clinical incident. Using free software and minimal computing resources an automated email alerting system was developed. The system identified patient admissions, compared them against patient cohorts and created alerts. It used only around 1,000 lines of Java7 code combined with free software and secure NHS mail accounts. The system currently sends alerts to many different teams at our hospital. The patient population includes 6,047 patients on one of our 10 monitored lists or special registers. From May to June 2013 the system alerted to 863 monitored patient admissions in 2,158 separate messages. This system has been adopted across multiple specialties, has been well received and has had a direct impact on patient care. Not only is this system efficient and effective, but importantly can be implemented with low cost and complexity and is hence easily reproducible across the NHS.