Date Published: February 7, 2019
Publisher: Public Library of Science
Author(s): Fanny Garnier, Cécile Couchoud, Paul Landais, Olivier Moranne, Emmanuel A. Burdmann.
Acute kidney injury requiring dialysis (AKI-D) is associated with high mortality. Information about its epidemiology is nonetheless sparse in some countries. The objective of this study was to assess its epidemiology and prognosis in metropolitan France.
Using the French hospital discharge database, the study focused on adults hospitalized in metropolitan France between 2009 and 2014 and diagnosed with AKI-D according to the codes of the French common classification of medical procedures. Crude and standardized incidence rates (SIR) by gender and age were calculated. We explored the changes in patients’ characteristics, modalities of renal replacement therapy (RRT), in-hospital care, and mortality, along with their determinants. Trends over time in the SIR for AKI-D, its principal diagnoses, and comorbidities were analyzed with joinpoint models.
Between 2009 and 2014, the AKI-D SIR increased from 475 (95% CI, 468 to 482) to 512 per million population (95% CI, 505 to 519). AKI-D was twice as high in men as women. Median age was 68 years. Over the study period, the AKI-D SIR steadily increased in all age groups, particularly in the elderly. The most common comorbidities were cardio-cerebrovascular diseases (64.8%), pulmonary disease (42.2%), CKD (33.8%), and diabetes (26.0%); all of these except CKD increased significantly over time. In 2009, heart failure (17.2%), sepsis (17.0%), AKI (13.0%), digestive diseases (10.7%), and shock (6.6%) were the most frequent principal diagnoses, with a significant increase in heart failure and digestive diseases. The proportion of patients with at least one ICU stay and continuous RRT increased from 80.3% to 83.9% and from 56.9% to 61.8% (p<0.001), respectively. In-hospital mortality was high but stable (47%) and higher in patients with an ICU stay. This is the first exhaustive study in metropolitan France of the SIR for AKI-D. It shows this SIR has increased significantly over 6 years, together with ICU care and continuous RRT. In-hospital mortality is high but stable.
Acute kidney injury (AKI) is a common and severe complication in hospitalized patients [1,2]. Due to its prognosis and frequency, AKI has been identified as a global public health issue . Whatever its etiology, AKI requiring dialysis (AKI-D) is associated with higher morbidity and mortality [4–6]. To develop preventive strategies and slow the growth of AKI-D, the International Society of Nephrology has recommended developing a better understanding of the epidemiology of AKI-D and its associated risk factors. Its global epidemiology, however, remains insufficiently characterized in the absence of accurate reporting of this event in many countries. Some studies from medico-administrative databases report dissimilar incidence rates over the past two decades [7–9]. Hsu et al. estimates that the crude incidence rate (CIR) of AKI-D rose from 222 to 533 per million population (pmp) between 2000 and 2009 in the United States , although a slightly more recent US study reports no increase in either the AKI-D incidence after adjustment for age and sex or in comorbidities between 2006 and 2014 . In England, Kolhe et al. report that the CIR for AKI-D jumped from 15.9 to 208.7 pmp between 1998 and 2013 . These increased incidence rates may be attributable to the growth of either susceptibility risk factors, such as advanced age, chronic kidney disease (CKD), and diabetes, or of exposure risk factors, such as nephrotoxic drugs or agents, sepsis, critical illness, and major surgery, together with changes in clinical practice related to indications for renal replacement therapy (RRT) [7,8,11,12]. Despite growing interest in AKI-D, national descriptions and prognostic data of these factors remain insufficient to enable the improvement of prevention and enhancement of healthcare organization.
For this first study of AKI-D in metropolitan France, using the national hospital discharge database, we showed a significant increase in the AKI-D SIR in adults from 475 to 512 pmp over the study period (2009–2014). This corresponds to an APC of +1.7%. In 2014, the incidence of AKI-D was more than three times higher than that of ESRD (163 pmp) . Note that this result is adjusted for population age and sex. We also reported an increase in several comorbidities, notably cardio-cerebrovascular, and described the modalities of dialysis used to manage AKI. As commonly reported, the principal diagnoses for these hospital stays were diverse: AKI, heart failure, sepsis, digestive diseases, respiratory diseases, and shock, with a significant increase in heart failure and digestive diseases. In 2014, most patients experienced at least one admission to ICU (83.9%) and at least one treatment by CRRT (61.8%); both of these rates increased significantly during the study period. Overall in-hospital mortality was higher in ICU than in non-ICU patients, but it decreased significantly from 54.3% to 51.7% over the study period.