@article{ref1,
title="How large should a cause of death be in order to be included in mortality trend analysis? Deriving a cut-off point from retrospective trend analyses in 21 European countries",
journal="BMJ open",
year="2020",
author="Mitratza, Marianna and Kardaun, Jan W. P. F. and Kunst, Anton E.",
volume="10",
number="1",
pages="e031702-e031702",
abstract="OBJECTIVES: The International Classification of Diseases (ICD-10) distinguishes a large number of causes of death (CODs) that could each be studied individually when monitoring time- trends. We aimed to develop recommendations for using the size of CODs as a criterion for their inclusion in long- term trend analysis.    Design: Retrospective trend analysis. Setting 21 European countries of the WHO Mortality Database.    Participants: Deaths from CODs (3- position ICD-10 codes) with ≥5 average annual deaths in a 15- year period between 2000 and 2016.    Primary and secondary outcome measures: Fitting polynomial regression models, we examined for each COD in each country whether or not changes over time were statistically significant (with α=0.05) and we assessed correlates of this outcome. Applying receiver operating characteristicROC curve diagnostics, we derived COD size thresholds for selecting CODs for trends analysis.   Results: Across all countries, 64.0% of CODs had significant long- term trends. The odds of having a significant trend increased by 18% for every 10% increase of COD size. The independent effect of country was negligible. As compared to circulatory system diseases, the probability of a significant trend was lower for neoplasms and digestive system diseases, and higher for infectious diseases, mental diseases and signs- and- symptoms. We derived a general threshold of around 30 (range: 28-33) annual deaths for inclusion of a COD in trend analysis. The relevant threshold for neoplasms was around 65 (range: 61-70) and for infectious diseases was 20 (range: 19-20).   Relationship between the likelihood for a COD to have a significant long-term trend with its size, corresponding ICD-10 chapter and country  V01.Y98 External causes of morbidity and mortality  Number of CODs 1992    Total number of deaths 3 005 539  Odds Ratio 1.20 (0.99 to 1.46)  Conclusions: The likelihood that long- term trends are detected with statistical significance is strongly related to COD size and varies between ICD-10 chapters, but has no independent relation to country. We recommend a general size criterion of 30 annual deaths to select CODs for long- term mortality- trends analysis in European countries.   Strengths and limitations of this study:  ► The first study to develop a criterion to select causes of death for monitoring purposes based on their annual number of deaths.   ► The analysis of a large sample of causes of death covering most European countries, using the WHO Mortality Database.   ► Criteria for selection of causes were derived for different types of causes of death.   ► Other criteria were not applied, such as causes of death that involve high healthcare costs or that are potentially modifiable.   © Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY. Published by BMJ.<p /> <p>Language: en</p>",
language="en",
issn="2044-6055",
doi="10.1136/bmjopen-2019-031702",
url="http://dx.doi.org/10.1136/bmjopen-2019-031702"
}