Between 1950 and 1999 the Scottish death rate, standardised to the 1950 population, declined
from 13.1 per 1000 to 7.8 for men and from 12 per 1000 to 6.3 for women. The main aim of this
thesis has been to establish the key influences on this decline. Thomas McKeown examined the
decline of mortality in an earlier time period (up to the 1970s) and concluded that: falls in deaths
from infectious diseases were responsible for the majority of the decline in mortality rate; and
the main influence on their decline was standards of living, in particular diet. This thesis has
updated McKeown's study for the latter half of the 20th century by establishing which causes of
death contributed the most to the fall in mortality in Scotland, and the main influences on their
decline.The causes of death which contributed most to the decline in mortality rates 1950-1999 were
established by digitising GRO(S) mortality records and calculating 'potential lives saved'. This
method allows an estimate to be made of the number of deaths which would be expected to
occur in 1999, taking into account changing age structure, ifthe death rates from 1950 still
applied. Tuberculosis (TB), stomach cancer (SC), ischemic heart disease (IHD) and stroke were
selected as case studies; these accounted for over 70% of the decline of male and female
mortalityThe trajectory of decline in these causes of death was then considered in detail and set in social
and medical context. The role of medicine was defined broadly, including not only treatments,
but also changes in the environment or in population behaviour which benefited health and could
be proven to have been inspired by medicine. This differs from McKeown's approach which had
a more clinical focus.The thesis has reached an alternative conclusion from that ofThomas McKeown. It is argued
that improving standards of living were responsible for some of the decline in SC and
haemorrhagic stroke mortality, and the pre-1950 decline ofTB; however, the main influence on
the decline of TB, IHD and ischemic stroke mortality post-1950 was medicine. Using the wider
definition of the influence of medicine adopted in this study, medicine is considered to account
for the majority of the decline in the identified causes of mortality. Medicine has, at last,
delivered important contributions to the life expectancy of the Scottish population
