Population-based incidence, mortality and quality of life in critically ill patients treated with renal replacement therapy: a nationwide retrospective cohort study in finnish intensive care units

INTRODUCTION Acute kidney injury (AKI) increases mortality and morbidity of critically ill patients. Mortality of patients treated with renal replacement therapy (RRT) is high. We aimed to evaluate the nationwide incidence of RRT-treated AKI in Finland, hospital and six-month mortality, and health-related quality of life (HRQoL) of these patients. METHODS We performed a retrospective cohort study including all general intensive care unit (ICU) admissions in Finland in 2007 through 2008. We identified patients who had received RRT due to AKI (RRT patients) and compared these patients to ICU patients who were not treated with RRT (non-RRT patients). The HRQoL was assessed by the EQ-5D index and visual analogue scale (VAS). RESULTS We analysed the final cohort of 24,904 patients, of whom 1,686 received RRT due to AKI. The incidence of RRT-treated AKI was 6.8% (95% confidence interval (CI) 6.5 to 7.1%) among ≥15-year-old general ICU patients, which corresponds to a yearly population-based incidence of 19.2 per 100,000 (95% CI 17.9 to 20.5/100,000). According to RIFLE (Risk, Injury, Failure) classification 26.6% (95% CI 26.0 to 27.2%) of patients had AKI (RIFLE R-F). Hospital and six-month mortality of RRT patients were 35.0% and 49.4%. At six-months, RRT patients perceived their health as good as non-RRT patients by VAS. CONCLUSIONS The population-based incidence of AKI treated with RRT was 19.2 per 100,000 in Finland and 6.8% of all general ICU patients. The hospital and six-month mortality rates were lower than previously reported for ICU-treated RRT patients.