In his PhD research project, Lammertink investigated a unique resource that he discovered as a Master’s student: the Amsterdam cause-of-death registry. Between 1854 and 1926, the Bureau of Statistics recorded for all Amsterdam residents not only the cause of death, but also other socio-economic data, such as gender and last home address. “Other municipalities also had death registers, but in Amsterdam the data were kept structurally for much longer,” says the researcher. “This information offered a unique insight into the shift from nineteenth-century disease patterns to modern causes of death.”
Fewer epidemics
A shift began around 1870, with people dying less often from infectious diseases and more often from so-called ‘degenerative diseases’, such as cancer or cardiovascular disease. Lammertink’s count shows that after the cholera epidemic of 1866 and the smallpox epidemic of 1871, mortality from these kinds of epidemics among Amsterdam’s adult population did not actually exceed mortality from modern diseases. “The fact that these epidemics were registered may also have contributed to this. Indeed, it showed that diseases spread rapidly in densely populated neighbourhoods. At the same time, certain population groups, who lived under similar conditions, were actually less affected, such as Amsterdam’s Jewish population. They lived segregated from the rest of the capital’s population and maintained religious precepts and traditions that promoted a more hygienic lifestyle.”
Home address and education
Today, there are clear socio-economic differences in mortality and specific causes of death. “Statistics Netherlands (CBS) determines an individual’s socio-economic position based on their level of education,” says Lammertink. “Highly educated people today seem to live healthier lives, and therefore die later and from different causes than lower educated people. But we did not know whether this was really new, because this kind of research is very difficult to carry out for time periods prior to the nineteenth century. However, the Amsterdam cause-of-death registry includes not only the cause of death, but also an individual’s last home address.”
Lammertink then looked into what the rental value was of the properties people lived in. This allowed him to estimate their income. “People who lived with five family members in a back room in the Jordaan district earned less than people in a spacious canal house. And it seems that people who paid the highest rent often also died at a later age than their contemporaries – and more often from degenerative diseases.”
“The top layer of the population ate healthier and worked under better conditions than the rest of the city dwellers,” the historian explains. “But the rich smoked a lot and so were relatively more likely to get lung cancer or cardiovascular disease. Nowadays, these are on the contrary the patterns we see in the lower social groups.” Still, he says, it is questionable whether there was really an increase in mortality from degenerative diseases in the nineteenth century. “Doctors have also simply become better at making diagnoses. Until 1870, doctors also often listed ‘unknown’ or ‘old age’ as the cause of death. These days it is much easier to detect degenerative diseases in the body.”
COVID-19
Socio-economic disparities in mortality in the Netherlands increased as a result of the COVID-19 pandemic. Lammertink: “There is a very clear health gap there. Less educated people were more likely to die from COVID-19, possibly because they did not or could not follow the health recommendations, and because they are more likely to suffer from conditions like COPD, due to smoking or obesity.”