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Published on: August 4, 2010
Under-detection of acute kidney injury in hospitalised patients: a retrospective, multi-site, longitudinal study
Craig A Campbell1,2, Ling Li1, Sradha Kotwal3,4
1Centre for Health Systems and Safety Research, Australian Institute of Health Innovation, Macquarie University, Sydney, New South Wales, Australia.
Insights
Acute kidney injury (AKI) is common in Australian hospitals, affecting 16.4% of patients. Despite increasing awareness, AKI remains significantly under-reported in patient records.
Area of Science:
- Nephrology
- Clinical Epidemiology
- Public Health
Background:
- Acute kidney injury (AKI) is a critical decline in renal function, often complicated by comorbidities, impacting patient outcomes.
- Limited Australian data exists on AKI incidence using the KDIGO creatinine-based definition.
Purpose of the Study:
- To determine the incidence of AKI in four New South Wales hospitals.
- To estimate the extent of AKI under-reporting using diagnostic codes.
Main Methods:
- A laboratory algorithm based on KDIGO criteria identified AKI retrospectively in adult patients (2009-2013).
- Comparison of algorithm-identified AKI with diagnostic codes reported during the same period.
Main Results:
- The laboratory algorithm detected AKI in 16.4% of patients and 12.4% of hospitalizations.
- Stage 1 AKI was most common (72.1%), with significant under-coding across all stages (15.9% for Stage 1).
- Laboratory-identified AKI incidence trended downwards, while coded incidence trended upwards.
Conclusions:
- Hospitalised AKI is significantly under-reported, despite apparent increases in clinician awareness.
- The study highlights a discrepancy between laboratory-identified AKI and clinical coding practices.
Background:
Acute kidney injury (AKI) is a rapid deterioration of renal function, often caused by a variety of co-existing morbidities complicating its recognition and treatment, leading to short- and long-term adverse clinical outcomes. There are limited data on the incidence of AKI in Australia using the Kidney Disease Improving Global Outcomes creatinine-based consensus definition.
Aim:
To determine the incidence and estimate the extent of under-reporting of AKI in four hospitals in the South-Eastern Sydney/Illawarra regions of New South Wales, Australia.
Method:
A laboratory algorithm based on the Kidney Disease Improving Global Outcomes creatinine-based definition for AKI was applied retrospectively to laboratory data for adult patients admitted to the study hospitals between 2009 and 2013 to identify those with AKI. The results were compared with the incidence of AKI based on diagnostic codes for AKI reported for the same period.
Results:
AKI was detected in 12.4% of all hospitalisations (46 101/370 969) and 16.4% of patients (31 448/192 133) across the 5-year study period using the laboratory algorithm. Of these, 72.1% were AKI Stage 1 (33 246/46101). AKI was coded in only 15.9% of hospitalisations with AKI Stage 1 (5294/33 246), 38.5% of hospitalisations with Stage 2 (2381/6185), and 46.8% with Stage 3 (3120/6670). Yearly incidence of laboratory-identified AKI trended downward between 2009 and 2013, while annual incidence determined by coding trended upward.
Conclusion:
Although coding trends suggested a continuous increase in clinician awareness of AKI across the study period, AKI in hospitalised patients remained significantly under-reported.
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