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Volume 33, 12 Issues, 2023
  Letter to the Editor     September 2023  

Problems in Coding Causes of Deaths

By Hilal Aksoy


  1. Department of Family Medicine, Faculty of Medicine, Hacettepe University, Ankara, Turkey
doi: 10.29271/jcpsp.2023.09.1082


We read with interest the original article titled “Risk of Cardiovascular Death in Osteosarcoma” by Jia et al.1 In the study, it was stated that the data were obtained from the database, extracted from the patients with primary osteosarcoma between the years 1975 and 2019.1

World Health Organization (WHO) recommends ICD-10 coding for recording causes of death. But, WHO also does not find it appropriate to write some ICD-10 codes while specifying the causes on death certificates, such as codes characterised as ill-defined causes of death when written as a cause of death; all codes from R00 to R94, all codes from R96 to R99 codes, all codes from Y10 to Y34, Y87.2, C76, C80, C97, I47.2, I49.0, I46, I50, I51.4, I51.5, I51.6, I51.9 and I70.9.2,3

WHO recommends performing diagnostic tests to avoid ill-defined and unknown causes of death.4,5 But, this is usually impossible for unsuspected deaths.

In most countries, abnormal laboratory and clinical findings and symptoms, which belong to ill-defined causes of death group, can be documented as the main causes of death. So, we think the major problem is differences between the disease codes specified in the hospital automation system and the names of the diseases stated in the death certificates and patient records.3,6

Since the accuracy and consistency of death statistics are largely dependent on physician-provided data, so physicians must be careful about this.

The authors stated as a limitation that the causes of death identified from death certificates may be misclassified. I wonder what the authors have done to minimise the limitation.

The author declared no competing interest.

HA: Conception design of the work, drafting of the initial manuscript, revising, critical analysis, and final approval of the work.


  1. Jia Y, Xiong Y, Peng Z, Wang G. Risk of cardiovascular death in osteosarcoma. J Coll Physicians Surg Pak 2023; 33(03): 266-9. doi: 10.29271/jcpsp.2023.03.266.
  2. Health metrics network, framework and standards for country health information systems; ed. 2nd, Genova: WHO; 2012.
  3. Mathers C, Fat D, Inoue M, Rao C, Lopez A. Counting the dead and what they died from: an assessment of the global status of cause of death data. Bull World Health Organ 2005; 83(3):171-7. doi: 10.29271/jcpsp.2023.03.266.
  4. World Health Organization, International statistical classification of diseases and related health problems (ICD-10) – Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified, World Health Organization 2011; 10th Revision, vol. 2, 2010 ed. Chapter XVIII, 2010.
  5. World Health Organization, International statistical classification of diseases related health problems (ICD-10)-Instruction, manual, World Health Organization 2011; 10th Revision, vol. 2, 2010 ed. p. 31-77.
  6. Ylijoki-Sorensen S, Sajantila A, Lalu K, Boggild H, Boldsen JL, Boel LWT. Coding ill-defined and unknown cause of death is 13 times more frequent in Denmark than in Finland. Forensic Sci Int 2014; 244:289-94. doi: 10.1016/ j.forsciint.2014.09.016.

Authors Reply Section

By Guangye Wang


  1. Dr. Guangye Wang, Department of Orthopaedics, The People's Hospital of Baoan, Shenzhen, China



According to the International Classification of Diseases, 10th Revision [ICD-10] codes definitions, there are six causes of death from cardiovascular disease in the SEER database: diseases of heart (I00-I09, I11, I13, I20-I51), hypertension without heart disease (I10, I12), cerebrovascular diseases (I60-I69), atherosclerosis (I70), aortic aneurysm and dissection (I71), and other diseases of arteries, arterioles, and capillaries (I72-I78).1,2

SEER registries use death certificates to determine the cause of death instead of autopsy or electronic chart information, which may introduce misclassification bias. Deaths from cardiovascular disease may thus be over/underestimated. Indeed relevant studies suggest that the causes of cardiovascular disease on death certificates may be overestimated.3,4 This is one of the limitations of this study, as this study is a retrospective study and is limited by the study data, which is something this study cannot avoid at this time, and this needs to be reduced by subsequent prospective studies.


  1. Fung C, Fossa SD, Milano MT, Sahasrabudhe DM, Peterson DR, Travis LB. Cardiovascular disease mortality after chemotherapy or surgery for testicular nonseminoma: A population-based study. J Clin Oncol 2015; 33(28): 3105-15. doi: 10.1200/jco.2014.60.3654].
  2. Sun S, Wang W, He C. Cardiovascular mortality risk among patients with gastroenteropancreatic neuroendocrine neoplasms: A registry-based analysis. Oxid Med And Cell Longer 2021; 2021: 9985814. doi: 10.1155/2021/9985814.
  3. Lloyd-Jones DM, Martin DO, Larson MG, Levy D. Accuracy of death certificates for coding coronary heart disease as the cause of death. Ann İnt Med 1998; 129(12):1020-6 doi: 10.7326/0003-4819-129-12-199812150-00005.
  4. Coady SA, Sorlie PD, Cooper LS, Folsom AR, Rosamond WD, Conwill DE. Validation of death certificate diagnosis for coronary heart disease: The atherosclerosis risk in communities (ARIC) study. J Clin Epidemiol 2001; 54(1): 40-50. doı: 10.1016/s0895-4356(00)00272-9.