Multidisciplinary Insights into Health Care Financial Risk and Hospital Surge Capacity, Part 2: High Population Density is Associated with Enhanced Year-to-Year Volatility in Many Aspects of Poor Health Including Health Care Worker Sickness Absence

Abstract

The weighted population density for 349 English local government areas, and the raw population density for a further 58 areas from Northern Ireland and Scotland, were used to demonstrate the role of high population density in the volatility associated with year-to-year total deaths and of excess winter mortality (EWM). Volatility in EWM was measured as the standard deviation over a 20-year period while for total deaths looked at the absolute value of the year-to-year difference expressed as standard deviation equivalents. The volatility in EWM for the most densely populated areas was almost double that of least populated areas. This reached a plateau when weighted population density exceeded 8,000 persons per square Km. For total deaths, the year-to-year average difference was around 35% higher when population density exceeded 7,000 persons per square Km. Death culminates a six-month period of increasing admission to acute hospital which can account for 55% of a person’s lifetime use of a hospital bed. Hence the volatility in death is a good measure of volatile costs and capacity pressures. Volatility in costs will follow the year-to-year pattern while hospital capacity pressures will tend to follow the EWM pattern, although with time lags. Population density acts to facilitate the spread of infectious agents, which increasingly arrive via international air travel. Population density is also associated with air pollution which acts to increase systemic inflammation in the population, thereby rendering them more susceptible to infection and adverse outcomes. Dysregulation of the inflammatory response to infection in the elderly implies that infection(s) with otherwise seemingly ‘trivial’ pathogens can then lead to surges in admissions and deaths which are then reported as a variety of (secondary) diagnoses. Unexplained patterns in average length of stay and the gender ratio for admissions for common conditions, which have previously been ignored, support this explanation. Similar unusual trends in the volatility associated with sickness absence among health care workers are also observed.

The Journal's Publisher, James Unland, had the opportunity to interview the author about this series of articles.  Audio of that interview can be found HERE