#1252 Non-standardized definition of chronic dialysis within German health claims data results in varying estimates for incidence and mortality

Abstract

Abstract Background and Aims Chronic dependency on dialysis in patients with chronic kidney failure (CKF) demands invasive, high-risk, and costly treatments. At present, there is no standardized definition for dialysis-dependent CKF within German health claims data from statutory health insurance (SHI) funds. Method Random samples from four year tranches (2012, 2014, 2016, 2018), each with 62,200 individuals aged ≥70 years, of German health claims data of the SHI AOK Nordost were analysed. Four literature-based definitions of dialysis-dependent CKF (1–4) and a newly developed definition, based on a billing logic with criteria required for monetary reimbursement for chronic dialysis treatments in patients with CKF by SHIs, were selected. The definitions were compared with regard to sociodemographic and clinical characteristics, dialysis-dependent CKF prevalence and incidence (standardized by year-, age group-, and sex-specific weights for Northeast-Germany), overall mortality, and direct health care costs. Results All definitions of dialysis-dependent CKF resulted in varying estimates of 12-month prevalence (0.33–0.61%) and six-month incidence (0.058–0.100%). Depending on the definition, 27.6% to 61.8% of incident individuals had a preceding acute kidney injury (AKI). Survival probabilities of individuals with dialysis-dependent CKF ranged from 70.2% to 88.1% and 60.5 to 81.3% after three and six months, respectively (Fig. 1). After stratification, survival probabilities differed less between the definitions in individuals without a preceding AKI. Monthly health care cost ranged from 6,010 to 9,606 EUR and varied strongly in out- and inpatient treatment costs depending on the definition. Cost was highest in inpatients with preceding AKI. Conclusion Due to a non-standardized definition of dialysis-dependent CKF in claims data we found varying case numbers, mortality, and health care costs, most probably in large part explained by the discrepant inclusion of individuals with short-term dialysis treatment due to AKI.