households with two or more cars. In general, vehicle ownership has been increasing and the
age of vehicles on the road has also been increasing.
Data on total population, household income, expenditure on alcohol, and population
by age cohorts was also collected from Regional Trends published by the Office of National
Statistics. These are used to control for other factors that are likely to affect casualties. GDP
and alcohol expenditure were adjusted for inflation and set to real values for 1998 pound
sterling. Age cohort data was not available for Scotland.
As discussed previously, several variables could be a good proxy for improvements in
medical care and technology over time. These include the length of inpatient stay in the
hospital, infant mortality rate, persons waiting for hospital treatment per capita, NHS staff per
capita and General Practitioners (GP) per capita. This data was collected from Regional
Trends and the Compendium of Health Statistics published by the Office of Health
Economics. Health care data were not available for the London region.
Table 1 shows the average change in these variables over time. Further analyses (not
shown) shows that in almost all regions the length of inpatient stay in the hospital has
decreased by about 50% over 20 years. Infant mortality rates have decreased by 62%
(highest) in the South East region and by 47% (lowest) in the Yorkshire region. The number
of persons (per capita) waiting for hospital treatment has increased in some of the regions and
decreased in some other regions. In Wales, it has increased by about 45% whereas in the
West Midlands, it has decreased by about 27%. NHS staff per capita shows no clear trend
between regions and almost no change in aggregate. It has increased in the East Midlands,
North West, South East, South West, West Midlands and Yorkshire and decreased in the East
Anglia, Northern region, Scotland and Wales.