Mortality in the Victorian asylum: was it so high? Standardised Mortality Rate compared with historical methods.

Mortality is closely linked to age, sex, and social and historical context. Standardised Mortality Rates (SMR) address these contextual factors by comparing mortality in a population under study with that in people of the same age and sex, the same period in history and from a similar cultural context. We use records from the Hatton Asylum and contemporaneous census data in order to calculate SMR in the asylum population, showing rates that were about 2.5 times greater than the population at the time. This is much lower than crude mortality rates, which we calculated as being more than seven times greater than in the population. The SMR method may enable a more meaningful understanding of mortality in asylums or other institutions.