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- Hernes, Eivor, et al.
(författare)
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High prostate cancer mortality in Norway evaluated by automated classification of medical entities.
- 2008
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Ingår i: European Journal of Cancer Prevention. - 0959-8278 .- 1473-5709. ; 17:4, s. 331-335
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Tidskriftsartikel (refereegranskat)abstract
- The new standard of cause of death classification is an automated selection of the underlying cause of death using the international software Automated Classification of Medical Entities (ACME). Norwegian mortality rates are, however, based on manual classification of deaths. The aim of this study was to investigate how the use of ACME would influence Norwegian prostate cancer mortality rates. A previously described cohort of Norwegian prostate cancer patients deceased during 1996 was applied. Multiple causes of death data based on information from death certificates, autopsies and queries was coded according to ACME specifications, thereby ACME selected the underlying cause of death. In addition, the underlying cause of death that originally was manually classified for the official mortality statistics was retrieved from Statistics Norway in all cases. Age-standardized prostate cancer mortality rates (world population) per 100,000 person-years were calculated. A total of 2012 cases were included. On the basis of ACME classification, the age-standardized prostate cancer mortality rate in Norway for 1996 would have been 24.4 (95% confidence interval: 22.9-26.0) as compared with the rate based on manual classification for the official mortality statistics of 24.9 (95% confidence interval: 23.4-26.5). Thus, automated classification by ACME does not significantly influence the age-adjusted Norwegian prostate cancer mortality rate for the year 1996. There is reason to assume that the use of manual classification of deaths is not a major explanation of the high prostate cancer mortality rates in Norway.
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- Johansson, Lars Age, et al.
(författare)
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Counting the dead and what they died of.
- 2006
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Ingår i: Bulletin of the World Health Organization. - 0042-9686 .- 1564-0604. ; 84:3, s. 254-
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Tidskriftsartikel (refereegranskat)
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- Johansson, Lars Age, et al.
(författare)
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Methodology of studies evaluating death certificate accuracy were flawed.
- 2006
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Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 59:2, s. 125-31
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND OBJECTIVE: Statistics on causes of death are important for epidemiologic research. Studies that evaluate the source data often give conflicting results, which raise questions about comparability and validity of methods. METHODS: For 44 recent evaluation studies we examined the methods employed and assessed the reproducibility. RESULTS: Thirty studies stated who reviewed the source data. Six studies reported reliability tests. Twelve studies included all causes of death, but none specified criteria for identifying the underlying cause when several, etiologically independent conditions were present. We assessed these as not reproducible. Of 32 studies that focussed on a specific condition, 21 provided diagnostic criteria such that the verification of the focal diagnosis is reproducible. Of 16 that discussed the difference between dying "with" and "from" a condition, eight described how competing causes had been handled. For these eight, the selection of a principal cause is reproducible, but in three the selection strategy conflicts with the international instructions issued by the World Health Organization. CONCLUSION: Methods and criteria are often insufficiently described. When described, they sometimes disagree with the international standard. Explicit descriptions of methods and criteria would contribute to methodologic improvement and would allow readers to assess the generalizability of the conclusions.
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- Johansson, Lars Age, 1951-
(författare)
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Targeting Non-obvious Errors in Death Certificates
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mortality statistics are much used although their accuracy is often questioned. Producers of mortality statistics check for errors in death certification but current methods only capture obvious mistakes. This thesis investigates whether non-obvious errors can be found by linking death certificates to hospital discharge data.Data: 69,818 deaths in Sweden 1995. Paper I: Analysing differences between the underlying cause of death from the death certificate (UC) and the main discharge condition from the patient’s last hospitalization (MDC). Paper II: Testing whether differences can be explained by ICD definitions of UC and MDC. Paper III: Surveying methods in 44 current studies on the accuracy of death certificates. Paper IV: Checking death certificates against case summaries for: i) 573 deaths where UC and MDC were the same or the difference could be explained; ii) 562 deaths where the difference could not be explained.Results: In 54% of deaths the MDC differed from the UC. Almost two-thirds of the differences were medically compatible since the MDC might have developed as a complication of the UC. Of 44 recent evaluation studies, only 8 describe the methods in such detail that the study could be replicated. Incompatibility between MDC and UC indicates a four-fold risk that the death certificate is inaccurate. For some diagnostic groups, however, death certificates are often inaccurate even when the UC and MDC are compatible.Conclusion: Producers of official mortality statistics could reduce the number of non-obvious errors in the statistics by collecting additional information on incompatible deaths and on deaths in high-risk diagnostic groups. ICD conventions contribute to the quality problem since they presuppose that all deaths are due to a single underlying cause. However, in an ageing population an increasing number of deaths are due to an accumulation of etiologically unrelated conditions.
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- Johansson, Lars Age, et al.
(författare)
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Unexplained differences between hospital and mortality data indicated mistakes in death certification : an investigation of 1,094 deaths in Sweden during 1995
- 2009
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Ingår i: Journal of Clinical Epidemiology. - : Elsevier BV. - 0895-4356 .- 1878-5921. ; 62:11, s. 1202-1209
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Mortality statistics are important for epidemiological research. We examine if discrepancies between death certificate (DC) and hospital discharge condition (HDC) indicate certification errors. STUDY DESIGN AND SETTING: From 39,872 hospital deaths in Sweden in 1995, we randomly selected 600 "cases," where DC and HDC were incompatible, and 600 compatible "controls," matched on sex, age, and underlying cause of death. We obtained case summaries for 1,094 (91%) of these. Using a structured protocol, we assessed the accuracy of DCs. RESULTS: Regression analysis indicated diagnostic group and "case" or "control" as the variables that most affected the accuracy. Malignant neoplasm "controls" had the highest accuracy (92%), and benign and unspecified tumor "cases," the lowest (20%). For all diagnostic groups except one, compatible "controls" had better accuracy than incompatible "cases." The exception, chronic obstructive lung disease, had low accuracy for both "cases" (54%) and "controls" (52%). CONCLUSION: Incompatibility between DC and HDC indicates a greater risk of certification errors. For some diagnostic groups, however, DCs are often inaccurate even when DC and HDC are compatible. By requesting additional information on incompatible cases and all deaths in high-risk diagnostic groups, producers of mortality statistics could improve the accuracy of the statistics.
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