Coding of COPD Exacerbations and the Implications on Clinical Practice, Audit and Research

Abstract

International Classification of Disease 10 (ICD-10) codes record hospital admissions. We aimed to measure the accuracy of COPD exacerbation (ECOPD) codes and examine coding practices for COPD exacerbation.

Prospective screening and ICD-10 codes were used to identify potential ECOPD within the DECAF internal validation cohort. Two coding searches were performed. The first search identified patients with an ECOPD discharge code, and a second, broad search was developed to identify all clinically confirmed ECOPD.

717 of 1,122 (64%) patients with an ECOPD code had confirmed ECOPD. Common reasons for misclassification in the 405 patients who did not have an ECOPD included: lack of obstructive spirometry to diagnose COPD; and hospital admission due to progressive malignancy, asthma or cardiovascular disease. The broad search identified an additional 297 patients with ECOPD missed by the ECOPD codes. The vast majority of this group had pneumonia complicating ECOPD.

ECOPD codes are insufficiently reliable to identify patients with clinically confirmed ECOPD for the purposes of audit or research. Search strategies should include pneumonia codes, specialist review of medical notes and spirometry confirmation of COPD.

Keywords:

• COPD
• COPD exacerbation
• pneumonia
• coding
• non-invasive ventilation

TRIAL REGISTRATION:

• UKCRN ID 14214

Acknowledgements

The authors thank all those involved in data collection and management in the previous DECAF studies.

Contributors

CE, JS, and SCB conceived, designed, and analysed the study. CE and JS wrote the initial draft of the manuscript, and all authors were involved in re-drafting.

Declaration of interest statement

John Steer has no conflicts of interest to declare. Carlos Echevarria reports grants from National Institute of Health Research, outside of the submitted work. Stephen Bourke reports grants from National Institute of Health Research, Philips Respironics and from Pfizer Open Air, personal fees from Pfizer, AstraZeneca, Chiesi and ResMed, and non-financial support from Boehringer Ingelheim and GlaxoSmithKline outside the submitted work. No author has financial relationships with any organisation that might have an interest in the submitted work.

Ethics approval

Ethics approval was provided by NRES Committee North East, UK.

Data sharing statement

Any individuals or parties interested in accessing data should contact CE or SCB.

Additional information

Funding

Data was used from the DECAF studies which were funded by the Department of Health, Breathe North appeal and Novartis Pharmaceuticals UK, and supported by the NIHR Clinical Research Network. The salary of CE was funded by the Northumbria NHS Foundation Trust Teaching and Research Fellowship programme.