The validity of death certificates: routine validation of death certification and its effects on mortality statistics

https://doi.org/10.1016/S0379-0738(00)00300-5Get rights and content

Abstract

The 3478 death certificates (7.1% of all annual death certificates) of this study comprise those national death certificates in 1995 submitted for validation to the panel representing both medical and nosological expertise. As such, it is highly selected and represents, from the nosological point of view, the most inconsistently filled-in portion of Finnish death certificates. The routine validation procedure is essentially based on exploitation of the extra medical information, i.e. the case history, on the Finnish death certificate form. Altogether, 2813 (80.9%) out of 3478 certificates could be adjusted at the primary panel session; the rest required further clarification. The re-assignment of cause of death by the panel and the impact of panel adjustments on the national mortality statistics is assessed here by comparing the initial death certification and the finally registered underlying cause of death grouped into ICD-9 major categories with special reference to the subcategories of neoplasm, cardiovascular disease (HVD) and unnatural death. A statistically significant decline (p<0.0001) in deaths, both in the category of symptoms, signs and ill-defined conditions and in the pulmonary circulation disease subcategory of HVD with 37.6 and 35.1%, respectively, was observed. The decrease of 11.1% in the benign or NUD neoplasm subcategory and the increase of 8.6 and 7.0% in the categories of endocrine disease, and musculo-skeletal and connective tissue disease, respectively, are essential observations as to the quality of the cause of death register. The effect on the HVD major category was practically nil. At the HVD-subcategorial level, a decrease of 14.0% for diseases of the veins and lymphatics and other circulatory diseases and an increase of 3.5% for hypertensive diseases (HYP) were the two next most obvious alterations to the diseases of the pulmonary circulation, but were without statistical significance. For ischaemic heart disease and other subcategories, the effects were minor. The unnatural deaths as a whole increased in the final statistics with only 0.9%. In the study data, categorial changes ranged from the decrease of 75.2% for symptoms, signs and ill-defined conditions to the increase of 77.3% for endocrine diseases. In conclusion, the Finnish death certificate form, death certification practices and cause of death validation procedure seem to serve the coding of causes of death for mortality statistics appropriately. The results of the study form a relevant reference background to evaluation of epidemiological studies on mortality.

Introduction

Reliable statistical mortality data requires precise and consistent cause of death coding which in turn depends on the correctness, that is, the completeness and accuracy of cause of death diagnoses on the death certificate, and the correct completion of the certificate. To ensure reliable death certification and the ultimate coding and selection of causes of death in the statistics, the certifying physicians in Finland are presumed always to code their cause of death diagnoses according to the national adaptation [1] of the International Statistical Classification of Diseases, Injuries and Causes of Death (ICD) to give a description of the circumstances of death, and to write a short case history, an abstract of the possible clinical examinations and therapy of the deceased. The Finnish death certificate form includes a blank item for this information to be freely written down to the extent that all diagnostic and other medico-legal information given on the certificate becomes justified. This state of affairs has created a specific national processing of the cause of death information on death certificates at Statistics Finland, the central statistical authority in the country. Where doubt arises about the correctness and/or accuracy of a single cause of death diagnosis, the internal consistency of death certificate as a whole or the proper selection of the underlying cause of death in particular, the nosologist is presumed to submit the certificate to the panel representing both the medical and nosological expertise.

At the panel session, the certified causes of death are discussed as to their correctness, accuracy, the cause-effect sequence and the primary medical cause of events leading to death. Other possible causes to be registered as contributing causes of death are proved as well. Finally, the underlying cause of death for coding is selected by the nosological expertise according to the international WHO rules and principles and following the conventional practices at the unit. The certificate may, however, be postponed pending further clarificatory measures, such as querying the certifier in order to be assessed in a later session when the answer is at the panel’s disposal. At this procedure, all medical particulars on death certificate are interpreted, assessed and, when relevant on medical grounds, incorporated into the cause of death diagnoses or their causal sequence for the underlying and the other possible causes of death to be correctly selected and coded.

The aim of this study is firstly to assess how our nationally modified death certificate form serves as a transferer of medical information on death to the cause of death register when inferred by an expert panel, and secondly to estimate the impact of this routine procedure on the cause of death register.

Section snippets

Material and methods

The data for this study consists of all the 3478 death certificates submitted by the nosologists to the panel in 1995. Infant deaths are not included because the concept of the underlying cause of death has not been used in deaths at the age of 0–12 months in Finland since 1987. Each death certificate and its processing at Statistics Finland were checked and the data collected by one of the authors (R.A. Lahti). The tabulated information was as follows: gender; (the potential) age at the end of

Demographic features

In Finland, 49,074 deaths at the age of 1 year or over were certified and registered in 1995. The frequency distributions of all these deaths and those of the study material by age and gender are shown in Table 2. The study data represents 7.1% of the yearly death certificates, 6.8% of the males and 7.4% of the females. There was obvious female over-representation in the two lowest age-groups, and females were over-represented overall by 4.0%. Men were fewer than expected in the three lowest

Discussion

From 1983, the death certifier in Finland has been obliged to on the certificate always include a short case history. This abstract includes information on the death and its circumstances so as to justify all the cause of death diagnostic and other conclusions entered on the certificate. This policy ensures that the certifier will concentrate on the information relevant to the medical certification of death, which is different from such things as clinical records of patient care. That

Acknowledgements

We owe our sincere gratitude to the director for population statistics, Riitta Harala and Hilkka Ahonen, senior statistician, for the opportunity to use the material and facilities of Statistics Finland. Hilkka Ahonen, assistant statisticians Terttu Turpeinen and Raija Maljanen, and the statisticians Irma Hölttä and Mauno Huohvanainen also deserve thanks for their practical co-operation. Prof. Seppo Sarna deserves our thanks for his expert guidance in the use of statistical methods. The English

References (25)

  • R.B Hill et al.

    The autopsy and health statistics

    Leg. Med.

    (1990)
  • R Hanzlick et al.

    The failure of death certificates to record the performance of autopsies (letter)

    JAMA

    (1993)
  • Cited by (215)

    View all citing articles on Scopus
    View full text