SP191THE EPIDEMIOLOGY OF ACUTE KIDNEY INJURY NOT REQUIRING DIALYSIS IN ENGLAND FROM 1998 TO 2013

Abstract

Introduction and Aims: Temporal trends in epidemiology of AKI, not requiring dialysis, have not been well described. With this objective, we combined a national database of all hospital discharges with national census data to investigate epidemiological trends of AKI as well as associated mortality and determinants of AKI in England between 1998 and 2013. Methods: We identified all cases of AKI by using validated International Classification of Diseases, Tenth Revision, Clinical Modification codes in all diagnosis codes from Hospital Episode Statistics, a data warehouse containing details of all admissions in England. To identify AKI not requiring dialysis, we excluded procedure code for haemodialysis in any of the 24 procedure codes. We also obtained mortality rate of all patients in England who did not have AKI from 1998‐99 to 2012‐13. Data during the 15‐year period were divided into three five‐year period. Univariate and binomial logistic regression was used to assess the relative contributions of all these variables simultaneously. All analysis was performed using SPSS version 22. Results: The incidence of AKI increased over twelve‐fold from 15,463 cases (317 per million people [pmp]) in 1998‐99 to 213,700 cases (3995 pmp) in 2012‐13 (figure 1). Overall unadjusted case‐fatality decreased from 42.3% in 1998‐03 to 27.1% in 2008‐13, p<0.001. Case‐fatality was highest when AKI was recorded in other diagnoses codes as compared to AKI in primary or secondary diagnosis codes (figure 2). Compared with 1998‐03, the adjusted odds ratio for death (OR) was lower in 2003‐08 at 0.64 (95% CI 0.63, 0.65) and in 2008‐2013 at 0.35 (95% CI 0.34, 0.35). In multivariate analysis, patients over the age of 85 years (OR 2.93; 95% CI 2.89, 2.97), Charlson comorbidity score of more than five (OR 2.75; 95% CI 2.71, 2.79), emergency admissions (OR 2.14; 95% CI 2.09.88, 2.18) and AKI coded in secondary and other diagnoses codes had higher odds of death, (OR 1.35; 95% CI 1.33, 1.36 and OR 2.17; 95% CI 2.15, 2.20). During the same period, the in‐hospital case‐fatality for all patients in England without the diagnosis of AKI in any of the diagnoses codes, decreased from 2.4% in 1998‐99 to 1.1% in 2012‐13. The proportion of patients dying with AKI in England increased from 2.5% in 1998‐99 to 22.5% in 2012‐13. Conclusions: In England, the incidence of AKI has increased and mortality has decreased over last 15 years. Efforts to reduce the incidence of AKI and improve survival should focus on the elderly, emergency admissions, those with multi‐morbidity and requiring transfer from hospitals without a nephrology service. (Figure Presented).