Top Charts 23-06: Are the top causes of death reflected in our search history?

^{Note: It is common in UK reporting, but not in US or Canada, to include dementia deaths (causes F01 and F03) together with Alzheimer’s disease deaths (cause G30). The numbers illustrated here are only in relation to Alzheimer’s disease to allow for international comparison.}

In 2020, COVID-19 dominated search terms –in fact, “coronavirus” was the most popular search in the world that year (Google's Year in Search - Google Trends). This is not surprising, of course, as it is a novel virus and resulted in a global pandemic.

Besides the obvious boom in interest in COVID-19, the biggest difference between a leading cause of death and its search popularity was that for “diseases of the heart” which consistently ranked among the top 3 leading causes of death across all 3 regions but was among the lowest popular searches. Any discrepancies between search popularity and leading causes of death were amplified when querying French terms in Canada (especially since the more popular terms such as “coronavirus” and “cancer” are the same in both English and French).

Interestingly, cancers (malignant neoplasms), despite being second to diseases of the heart in leading causes of death in the United States, were much more popular in searches than diseases of the heart. (This was also true for Canada and the United Kingdom, where malignant neoplasms are the top cause of death.) There are many reasons why the relative frequency of a search term might increase, but this could be a partial indication that we are more concerned with certain causes of death than others.

The key questions are:

• What drives the discrepancies between what we search for and what we die from?
• Are these discrepancies a reflection of a failure in public health messaging? And what can we do to redress the balance?
• Are the causes of death with low search rates an indication of blind spots for health behaviours? Could they be an indication of future problems being added to the longevity pipeline?

What do you think?

^{Sources for leading causes of death in each region:}

• ^{Canada: Leading causes of death, total population, by age group (statcan.gc.ca)}
• ^{USA: NCHS Data Brief, Number 427, December 2021 (cdc.gov)}
  • ^{Data for chronic liver disease deaths in 2020: How Many People Have Liver Disease? - American Liver Foundation}
• ^UK:
  • ^{England and Wales - Deaths registered in England and Wales - Office for National Statistics (ons.gov.uk)}
  • ^{Deaths registered in England and Wales - Office for National Statistics (ons.gov.uk)}
    • ^{Data: Nomis - Official Census and Labour Market Statistics - Nomis - Official Census and Labour Market Statistics (nomisweb.co.uk)}
  • ^{Scotland - Most frequent causes - ScotPHO,}
    • ^{Data: List of Data Tables | National Records of Scotland (nrscotland.gov.uk)}
  • ^{Northern Ireland - Registrar General Annual Report 2020 Cause of Death | Northern Ireland Statistics and Research Agency (nisra.gov.uk), Section 6 - Cause_Death_Tables_2020_Revised June 2022.xlsx (live.com)}
    • ^{Data: Registrar General Annual Reports 2020 | Northern Ireland Statistics and Research Agency (nisra.gov.uk)}

^{We used Google Trends to capture the relative interest in different search terms relating to the 10 leading causes of death in all 3 regions.}

^{FAQ about Google Trends data - Trends Help}

^{The causes of death with ICD-10 codings as well as the queried terms for each cause of death are as follows:}