A Validation Study of Administrative Health Care Data to Detect Acute Kidney Injury in the Pediatric Intensive Care Unit

Abstract

Background:Large studies evaluating pediatric acute kidney injury (AKI) epidemiology and outcomes are lacking, partially due to underuse of large administrative health care data.Objective:To assess the diagnostic accuracy of administrative health care data-defined AKI in children admitted to the pediatric intensive care unit (PICU).Design:Retrospective cohort study utilizing chart and administrative data.Setting:Children admitted to the PICU at 2 centers in Montreal, QC.Patients:Patients between 0 and 18 years old with a provincial health insurance number, without end-stage renal disease and admitted to the PICU between January 1, 2003, and March 31, 2005, were included.Measurements:The AKI was defined from chart data using the Kidney Disease: Improving Global Outcomes (KDIGO) definition (Chart-AKI). The AKI defined using administrative health data (Admin-AKI) was based on International Classification of Disease, Ninth Revision (ICD-9) AKI codes.Methods:Data available from retrospective chart review, including baseline and PICU patient characteristics, and serum creatinine (SCr) and urine output (UO) values during PICU admission, were merged with provincial administrative health care data containing diagnostic and procedure codes used for ascertaining Admin-AKI. Sensitivity, specificity, positive, and negative predictive value of Admin-AKI compared with Chart-AKI (reference standard) were calculated. Univariable associations between Admin-AKI and hospital mortality were evaluated.Results:A total of 2051 patients (55% male, mean age at admission 6.1 ± 5.8 years, 355 cardiac surgery, 1696 noncardiac surgery) were included. The AKI defined by SCr or UO criteria occurred in 52% of cardiac surgery patients and 24% of noncardiac surgery patients. Overall, Admin-AKI detected Chart-AKI with low sensitivity, but high specificity in cardiac and noncardiac surgery patients. Sensitivity increased by 1.5 to 2 fold with each increase in AKI severity stage. Admin-AKI was associated with hospital mortality (13% in Admin-AKI vs 2% in non-AKI, P < .001).Limitations:These data were generated in a PICU population; future research should study non-PICU populations.Conclusions:Use of administrative health care data to define AKI in children leads to AKI incidence underestimation. However, for detecting more severe AKI, sensitivity is higher, while maintaining high specificity.

Acute Kidney Injury in Critically Ill Children Is Not all Acute: Lessons Over the Last 5 Years

“…Using administrative data is a cost-effective method for examining long-term outcomes in a large population. A systematic review in adults has demonstrated that AKI is identified by administrative health data with low sensitivity, but high specificity; similar results were also obtained from a validation study for identifying AKI in the PICU (42,43). Adult studies have used databases to evaluate the association between AKI and long-term CKD development (22).…”

Long-Term Outcomes of Children Undergoing Dialysis-treated AKI: Some Opinions and Prospects

“…Further, administrative database codes are better at detecting stage 3 AKI than stage 1-2 AKI, which would create selection bias. 7 We acknowledge Wei's 2 comment on the greater number of deaths versus kidney failure events contributing to our composite end point. However, the incidence of both kidney failure and death were also separately higher in the dialysistreated AKI cohort.…”

“…We did not use a combination of AKI and dialysis codes to define dialysis-treated AKI, given that administrative codes for AKI have a low sensitivity (,15%) in children. 7 This would significantly reduce the size of our dialysistreated AKI cohort. Although understanding differences in long-term kidney outcomes after dialysis-treated versus less severe forms of AKI is important, this was not our focus.…”

A Review on the Application and Limitations of Administrative Health Care Data for the Study of Acute Kidney Injury Epidemiology and Outcomes in Children

“…(1) acute kidney injury, aki, acute renal failure, or continuous renal replacement therapy, and (2) admin * adj3 data * to identify validation studies published since this systematic review, which identified an additional eight studies. A summary of the results of these studies (48)(49)(50)(51)(52)(53)(54)(55) and a selection of those published in the systematic review (56)(57)(58)(59)(60)(61) are included in Table 2. To our knowledge, this represents the most up-to-date summary of validation studies for AKI administrative health research.…”