The concurrent experience of multiple health conditions (often termed
multimorbidity) has become an important issue in recent years. Most research on this
topic uses clinical data (e.g. GP or hospital records) that lack important socio-contextual
information about the lives of people with multiple conditions. Population
health surveys can help to overcome these limitations, but identifying people who have
multiple conditions is problematic. Decisions need to be taken regarding what is
meant by a condition, which ones should be included, and how multiple should be
defined. These decisions tend to be based on what data are available, rather than on
any universal inclusion criteria or theoretical underpinnings.
This thesis used an approach informed by sociological theory and principles drawn
from critical realist philosophy to estimate the prevalence of multiple conditions
among adults (16+) in the general population, using data from the 1998 and 2008-
2011 Scottish Health Surveys. It explicitly acknowledged the multiple, contested and
constructed nature of health, illness and diagnosis; the limits of empirical enquiry; and
the need to approach concepts such as multiple conditions critically. To support the
decision-making process, longitudinal analyses of mortality were used to examine the
impact of including various contested conditions on people’s long-term chance of
survival (if there was no evidence of impact then the definition was rejected). The final
measure of multiple conditions arrived at suggested that 24.9% of adults had multiple
conditions (compared with 17.2% using the survey’s original, unadjusted, measure).
This measure was then used to explore how this status related to people’s wellbeing,
which helped to highlight importance differences in experiences.
Among adults with multiple conditions, 33.5% of those in the most deprived areas
had low wellbeing compared with 13.5% of those in the least deprived areas. Low
wellbeing was also higher among people with multiple conditions aged under 65 than
those aged 65 and over, especially for those living in areas of high deprivation. There
was some evidence that having multiple conditions and additional vulnerabilities (e.g.
psychological distress, living in a deprived area, having activity limitations) before the
age of 55 increased people’s risk of mortality, which might result in older populations
appearing to have better wellbeing due to less healthy people not reaching old age.
Working-age people with multiple conditions were also more likely than people of the
same age with no conditions to be economically inactive, to not live in an owner-occupied
property, and not have a co-resident partner. All of which suggest that poor
health at younger ages limits access to the social and economic norms enjoyed by most
people.
The approach adopted arguably helped to avoid over-classifying largely healthy people
as having multiple conditions, while still ensuring that people’s own perspectives on
their health were not under-privileged with respect to more traditional biomedically-focused
approaches. However, it was also clear that the experiences of adults with
multiple conditions are highly varied, and in particular, socially stratified. This
heterogeneity has implications for research in this field, as well as clinical practice and
public health policy. Recommendations for better reflecting this diversity in future
studies included collecting more measures of functional capacity, aspirations, illness
experiences, and social stressors (such as financial insecurity)