Validity of ICD-10 diagnoses of overweight and obesity in Danish hospitals
Received 8 May 2019
Accepted for publication 15 August 2019
Published 11 September 2019 Volume 2019:11 Pages 845—854
Checked for plagiarism Yes
Review by Single-blind
Peer reviewer comments 2
Editor who approved publication: Professor Eyal Cohen
Sigrid Bjerge Gribsholt,1,2 Lars Pedersen,1 Bjørn Richelsen,3 Reimar Wernich Thomsen1
1Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark; 2Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Aarhus, Denmark; 3The Steno Diabetes Centre Aarhus, Aarhus University Hospital, Aarhus, Denmark
Correspondence: Sigrid Bjerge Gribsholt
Department of Clinical Epidemiology, Aarhus University Hospital, Olof Palmes Allé 43-45, Aarhus N 8200, Denmark
Tel +45 6 165 1148
Purpose: Health care databases may be a valuable source for epidemiological research in obesity, if diagnoses are valid. We examined the validity and completeness of International Classification of Diseases, 10th revision [ICD-10] diagnosis coding for overweight/obesity in Danish hospitals.
Patients and methods: We linked data from the Danish National Patient Registry on patients with a hospital diagnosis code of overweight/obesity (ICD-10 code E66) with computerized height and weight measurements made during hospital contacts in the Central Denmark Region Clinical Information System. We computed the positive predictive value (PPV) of the IDC-10 diagnosis of overweight/obesity, using a documented body mass index (BMI) ≥25 kg/m2 as gold standard. We also examined the completeness of obesity/overweight diagnosis coding among all patients recorded with BMI ≥25 kg/m2.
Results: Of all 19,672 patients registered with a first diagnosis code of overweight/obesity in the National Patient Registry, 17,351 patients (88.2%) had any BMI measurement recorded in the Central Denmark Region Clinical Information System, and 17,240 patients (87.6%) had a BMI ≥25 kg/m2, yielding a PPV of 87.6% (95% CI: 87.2–88.1). The PPV was slightly higher for primary diagnosis codes of overweight/obesity: 94.1% (95% CI: 93.3–94.8) than for secondary diagnosis codes: 86.1% (95% CI: 85.6–86.6). The PPV increased with higher patient age: from 75.3% (95% CI: 73.8–76.9) in those aged 18–29 years to 94.7% (95% CI: 92.6–96.9) in patients aged 80 years and above. Completeness of obesity/overweight diagnosis coding among patients recorded with BMI ≥25 kg/m2 was only 10.9% (95% CI: 10.8–11.0).
Conclusion: Our findings indicate a high validity of the ICD-10 code E66 for overweight/obesity when recorded; however, completeness of coding was low. Nonetheless, ICD-10 discharge codes may be a suitable source of data on overweight/obesity for epidemiological research.
Keywords: obesity, validation, diagnosis code
This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at https://www.dovepress.com/terms.php and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.Download Article [PDF] View Full Text [HTML][Machine readable]