Concerning trends in Ambulance call-out data for England - Loss of Consciousness
In my last post I discussed the variation in cardiac and respiratory arrest ambulance call-out data over the last 3 years. But there’s another set of data in the ambulance call-out records that is of interest — the variation in call-outs due to loss of consciousness. These data are shown below, using the same convention as the previous post:
These data are rather interesting — instead of things getting worse, the advent of covid appears to reduce (improve) ambulance call-outs related to loss of consciousness. I think this is explained by health-seeking behaviour, ie:
Pre-covid we see a broadly flat level of ambulance call-outs related to loss of consciousness, at around 1,100 calls per day.
During the initial covid wave (spring 2020) people avoided hospital — lockdown was severe and people were told not to go to hospital unless absolutely necessary. Unlike the situation with cardiac arrests (for example) it is likely that in the case of people falling unconscious the advice was to wait to see if the individual recovered.
During summer 2020 the health service gradually returned to a level of normality, and advice changed to take anyone with an unexplained loss of consciousness to hospital. This led to a return to normal (baseline) levels of ambulance call-outs for loss of consciousness by August 2020.
In autumn 2020 the situation deteriorated again, and people once more avoided going to hospital.
And in spring 2021 there was a return to normal levels of ambulance call-outs related to loss of consciousness.
The important part of the data is seen during summer 2021 — there was an increase in ambulance call-outs for loss of consciousness to approximately 25% above the baseline level. Since then this has started to return to normal, but is still approximately 10% above baseline. The graph shows a peak in ambulance call-outs during the peak of the Delta wave during mid summer 2021, but note that there was no similar peak during previous covid waves — loss of consciousness was not associated with covid waves before this point (indeed, the opposite is seen).
I include in the insert section a graph of vaccination levels during this period — There appears to be a correlation, with increasing call-outs related to loss of consciousness as more in the population get vaccinated. I note once more that while correlation does not equal causation, there is enough of a statistical signal here to warrant urgent investigation.