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Cause of Death and Disease

Cause of Death: Immediate vs Underlying

  • The debate about why death counts differ (e.g., in The US 700k vs 1.1M deaths attributed to COVID) hinges on how cause of death is determined and recorded.
  • World Health Organization (WHO) guidance vs US reporting: WHO shapes international standards; the US National Vital Statistics System (NVSS) follows specific rules for data collection and reporting, often driven by insurance systems and public health needs.
  • Cause of death is described as the underlying cause which initiated the cascade leading to death; data are collected on an underlying cause, but also recorded with information about immediate causes and other significant conditions.
  • Immediate vs underlying:
    • Immediate cause: the final condition resulting in death (e.g., cardiac arrest).
    • Underlying cause: the disease or injury that started the sequence leading to the immediate cause (e.g., coronary heart disease causing a heart attack).
  • Example chain: diabetes → coma → kidney failure → death. Here, the immediate cause is kidney failure; the underlying cause is diabetes, the condition that started the cascade.
  • Other significant conditions may be listed to provide context for public health surveillance (e.g., diabetes, COPD, obesity) and to capture comorbid factors; autopsy data and additional information may be recorded in state-level systems.
  • Manner of death (e.g., natural, accidental, homicide) may be recorded; some states collect additional information such as pregnancy status.
  • A single death certificate can include multiple contributing factors and conditions that illuminate the patient’s health profile, but mortality statistics often rely on the underlying cause.
  • The WHO approach to data: while the underlying cause is primary, other significant conditions are also logged to better understand disease interactions and risk factors.
  • The practical reason for multiple data fields: public health can analyze risk factors, comorbidities, and clusters of diseases, rather than focusing on a single immediate cause.
  • Real-world illustration: a person with arteriosclerosis (narrowed arteries) who develops a blood clot and then has a heart attack and dies. Medically, the underlying cause may be coronary artery disease; the immediate cause would be the heart attack, with the chain and contributing factors documented in the record.
  • Different states may vary in how they record and report data; some fields (e.g., autopsy status) may influence how cause of death is classified.
  • Why it matters: cause-of-death data guide public health priorities, funding, and prevention programs, and they influence how we interpret trends over time.

Data Systems, Standards, and Sources

  • National Vital Statistics System (NVSS): collects death certificate data from every state and later reports to the WHO; the NVSS is a key public data source, historically accessible and used for trend analysis.
  • Funding and policy context: public health data collection has faced political scrutiny and funding changes; debates about whether to maintain or cut NVSS funding affect historical data access and timely updates.
  • Public access: NVSS data are publicly available, with historical data extending back to the early 20th century, used to analyze leading causes of death by year and category.
  • Leading causes of death (illustrative), with approximate values from 2018–2021:
    • Cardiovascular disease: 0.20\%\
    • Cancer: 0.18\%\
    • Respiratory diseases: 0.06\%\
    • COVID-19: 0.06\%\
    • Other leading causes include stroke and diabetes (numbers not explicitly provided in the transcript for those items, but they are listed among leading causes).
  • Public health data tools:
    • CDC WONDER (an online data portal) allows exploration of leading causes of death, filtering by category, year, and population subgroup; data can be traced