Objective The utility of International Classiﬁcation of Diseases (ICD) codes relies on the accuracy of clinical reporting and administrative coding, which may be influenced by country-specific codes and coding rules. This study explores the accuracy and limitations of the Australian Modification of the 10th revision of ICD (ICD-10-AM) to detect the presence of cirrhosis and a subset of key complications for the purpose of future large-scale epidemiological research and healthcare studies.
Design/method ICD-10-AM codes in a random sample of 540 admitted patient encounters at a major Australian tertiary hospital were compared with data abstracted from patients’ medical records by four blinded clinicians. Accuracy of individual codes and grouped combinations was determined by calculating sensitivity, positive predictive value (PPV), negative predictive value and Cohen’s kappa coefficient (κ).
Results The PPVs for ‘grouped cirrhosis’ codes (0.96), hepatocellular carcinoma (0.97) ascites (0.97) and ‘grouped varices’ (0.95) were good (κ all >0.60). However, codes under-detected the prevalence of cirrhosis, ascites and varices (sensitivity 81.4%, 61.9% and 61.3%, respectively). Overall accuracy was lower for spontaneous bacterial peritonitis (‘grouped’ PPV 0.75; κ 0.73) and the poorest for encephalopathy (‘grouped’ PPV 0.55; κ 0.21). To optimise detection of cirrhosis-related encounters, an ICD-10-AM code algorithm was constructed and validated in an independent cohort of 116 patients with known cirrhosis.
Conclusion Multiple ICD-10-AM codes should be considered when using administrative databases to study the burden of cirrhosis and its complications in Australia, to avoid underestimation of the prevalence, morbidity, mortality and related resource utilisation from this burgeoning chronic disease.
- hepatic encephalopathy
- health service research
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EEP and PCV contributed equally.
Contributors PCV and EEP conceived and planned the study. PCV and KLH obtained ICD-10-AM data from QHAPDC, and KLH and LUH coordinated clinical data collection by ALJ, BJM, NTB and EEP. CL managed the databases and data entry was cross-checked by KLH and ALJ. KLH, GH and VB merged and analysed the data. PCV, EEP, KLH, GH and CM interpreted study findings. PCV, EEP and KLH drafted the manuscript. All authors reviewed and approved the final version for publication and have agreed to be accountable for all aspects of the work.
Funding KLH was supported by a Health Innovation, Investment and Research Office (HIIRO) Clinical Research Fellowship. PCV was supported by an Australian National Health and Medical Research Council (NHMRC) Career Development Fellowship (no. 1083090).
Competing interests None declared.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data have not been made publicly available due to requirements of Research Ethics and Governance approvals. Requests to collaborate and share data may be directed to the corresponding author.
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