Evaluation of Left Truncation and Censoring When Changing the Use of the International Classification of Diseases Eighth Revision Codes to Tenth Revision Codes in the Danish National Patient Registry
IF 3.4 2区 医学Q1 PUBLIC, ENVIRONMENTAL & OCCUPATIONAL HEALTH
Søren Korsgaard, Frederikke Schønfeldt Troelsen, Katalin Veres, Cecilia Hvitfeldt Fuglsang, Henrik Toft Sørensen
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引用次数: 0
Abstract
Purpose: In the Danish National Patient Registry (DNPR), covering all Danish hospitals and widely used in research, diseases have been recorded using International Classification of Diseases (ICD) codes, transitioning from the Eighth to the Tenth revision in 1994. Uncertainty exists regarding whether including ICD-8 codes alongside ICD-10 is needed for complete disease identification. We assessed the extent of left-truncation and left-censoring in the DNPR arising from omitting ICD-8 codes. Patients and Methods: We sampled 500,000 Danes ≥ 40 years of age in 1995, 2010, and 2018. From the DNPR, we identified cardiovascular, endocrine, gastrointestinal, neurological, pulmonary, rheumatic, and urogenital diseases as well as fractures. We obtained the number of people with a disease recorded with ICD-8 codes only (ie, the ICD-8 record would be left-truncated by not using ICD-8 codes), ICD-8 plus ICD-10 codes (ie, the ICD-8 record would be left-censored by not using ICD-8 codes), and ICD-10 codes only. For each ICD group, we calculated the proportion of people with the disease relative to the total sample (ie, 500,000 people) and the total number of people with the disease across all ICD groups. Results: Overall, the left-truncation issue decreased over the years. Relative to all people with a disease, the left-truncated proportion was for example 59% in 1995 and < 2% in 2018 for diabetes mellitus; 93% in 1995, and 54% in 2018 for appendicitis. The left-truncation issue increased with age group for most diseases. The proportion of disease records left-censored by not using ICD-8 codes was generally low but highest for chronic diseases. Conclusion: The left-truncation issue diminished over sample years, particularly for chronic diseases, yet remained rather high for selected surgical diseases. The left-truncation issue increased with age group for most diseases. Left-censoring was overall a minor issue that primarily concerned chronic diseases.
期刊介绍:
Clinical Epidemiology is an international, peer reviewed, open access journal. Clinical Epidemiology focuses on the application of epidemiological principles and questions relating to patients and clinical care in terms of prevention, diagnosis, prognosis, and treatment.
Clinical Epidemiology welcomes papers covering these topics in form of original research and systematic reviews.
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When considering submission of a paper utilizing publicly-available data, authors should ensure that such studies add significantly to the body of knowledge and that they use appropriate validated methods for identifying health outcomes.
The journal has launched special series describing existing data sources for clinical epidemiology, international health care systems and validation studies of algorithms based on databases and registries.