FC 046INCIDENCE OF NOSOCOMIAL ACUTE KIDNEY INJURY (AKI) IN A COHORT OF COMMUNITY-DWELLING OLDER ADULTS OVER 8 YEARS OF OBSERVATION

Abstract

Abstract Background and Aims Acute kidney injury (AKI) is amongst the most common in-hospital complications especially in old age. Epidemiological data on incidence rates (IR) of nosocomial AKI in individuals aged 70+ years, stratified by age, gender and pre-existing diseases are scarce because older adults are usually underrepresented in clinical research. Method We used data from the Berlin Initiative Study (BIS), a longitudinal, population-based cohort of adults aged ≥70 with biennial follow-up visits (including blood and urine tests) in combination with claims data from the AOK Nordost insurance fund to complement information on diagnoses and in-hospital procedures (based on ICD-10 and OPS coding). Nosocomial AKI was defined as documented in-hospital diagnosis (ICD-10: N17.xx) excluding cases with AKI as admission diagnosis. Incidence rates (IR) and 95% confidence intervals (CI) of the first nosocomial AKI were calculated with the number of incident cases during observation divided by the total person-years of follow-up, for AKI cases truncated at the first incidence of nosocomial AKI. IR are reported by age strata, sex and preexisting diseases (diabetes, arterial hypertension, atrial fibrillation, heart failure, angina pectoris, peripheral artery disease and impaired kidney function). Results In 2020 individuals (mean age 80.5 years; 52.6% women), 383 developed nosocomial AKI over the median [IQR] follow up time of 8.8 [5.9-9.3] years (Fig.1). The IR of nosocomial AKI was 26.8 (95%CI 24.1-29.6) per 1000 person years among all patients, with higher IR in men compared to women, and - when stratified by age - lowest IR in age category 70-75 versus the highest IR in age category of ≥ 90 years (Fig.1). IR per 1000 person years were higher in patients with diabetes mellitus (IR: 39.3 vs 22.7), arterial hypertension (IR: 31.1 vs 12.2), chronic heart failure (IR: 41.9 vs 22.3), angina pectoris (IR: 37.6 vs 25.7), peripheral artery disease (IR: 55.0 vs 25.1) and impaired kidney function (IR: 43.3 vs 12.4), respectively (Fig.2). Conclusion Nosocomial AKI is an in-hospital complication common in older adults with IRs rising continuously with age above the age of 70 years. IR of AKI are considerably higher in patients with cardiovascular comorbidities. A better understanding of the patient population at risk is of great clinical relevance when aiming to improve prevention strategies.