Original article
National adaptations of the ICD rules for classification—A problem in the evaluation of cause-of-death trends

https://doi.org/10.1016/S0895-4356(96)00426-XGet rights and content

Abstract

In 1981, the registration routines of the Swedish cause-of-death register were adjusted. The aim of this study was to assess what influence these changes in registration practice might have had on the cause-of-death trends after 1981. The Eighth Revision of the International Classification of Diseases (ICD-8) was used throughout the study period (1976–1985).

Significant changes in the registered number of cases were found in 13 of the 18 diagnostic groups scrutinized. Four main types of outcomes were observed: (a) the number of underlying causes increased while the number of contributing causes decreased or vice versa; (b) the number of both underlying and contributory causes changed in the same direction, due to the transfer of a diagnostic group from one ICD category to another; (c) the number of both underlying and contributory causes changed in the same direction, but not due to the transfer of a diagnostic group; or (d) the number of either underlying or contributory causes changed, but not both. In general, the altered registration practice led to more conditions that are often considered as terminal complications to other diseases being registered as the underlying cause of death. While most of the 1981 instructions meant a more literal application of the ICD-8, those concerning cardiac valvular diseases deviated substantially from it. We conclude that (a) important changes in registration practice may occur at any point in time, and not only in connection with the implementation of a new version of the ICD; and (b) national adaptations of the ICD coding instructions may amount to a reversal of the instructions included in the ICD manuals. These findings must be considered when comparing cause-of-death statistics from different countries, and both underlying and contributing cause-of-death statistics should be considered in such analyses of cause-of-death trends.

References (21)

There are more references available in the full text version of this article.

Cited by (28)

  • A population-based case-cohort study of the risk of myocardial infarction following radiation therapy for breast cancer

    2007, Radiotherapy and Oncology
    Citation Excerpt :

    Although we have defined cases of vAMI and dAMI to be mutually exclusive, we have not combined vAMI and dAMI as a composite outcome. The fact and date of death from death certification are rarely disputed, however, assignment of cause of death by attending physicians, and coding of the cause chosen by physicians, has often been doubted [49–56]. Although the majority of vAMI and dAMI events occurred among women exposed to RT at the age of 60 or older, the proportion of dAMI events occurring among those exposed under the age of 60 was very small, compared to the proportion of vAMI events in this age group.

  • Methodology of studies evaluating death certificate accuracy were flawed

    2006, Journal of Clinical Epidemiology
    Citation Excerpt :

    This makes mortality data from death certificates highly comparable both internationally as well as nationally. Whereas cause-of-death information on death certificates is collected using highly structured and standardized forms, it has been amply demonstrated that many death certificates are not properly completed [2–8]. Many studies have shown discrepancies between cause of death reported on death certificates and cause of death reported on other sources such as medical records and autopsies.

  • Cause of death and long-term survival in patients with neuro-epithelial brain tumours: A population-based study

    2003, European Journal of Cancer
    Citation Excerpt :

    The patients of the pilot study may therefore not have correctly reflected the main study population and patients who did not receive radiotherapy may have been under-represented. Death certificates also do not always correctly state the underlying cause of death [22,23]. In a study carried out in the USA, based on computer linkage of death records and hospital discharge records, the underlying causes of death and discharge diagnoses for 9724 patients were compared; the agreement between cause and closest medical record diagnosis was 72% [24].

  • Long-term effects of legislation and local promotion of child restraint use in motor vehicles in Sweden

    2001, Accident Analysis and Prevention
    Citation Excerpt :

    But no changes except in terms of denotation were made to coding of the types of injuries considered here. In general, however, there are reasons to be cautious with regard to the implications of coding changes (Jansson et al., 1997). In the case of our study, there was a significant difference across areas in the reduction of injuries during the period investigated.

View all citing articles on Scopus

This study was financially supported by Karolinska Institute, The National Board of Social Health and Welfare and Stockholm County Council, Sweden.

View full text