Measurements Impairment: MI and stroke patients completed condition specific
measures of impairment. These were the Orgogozo Neurological Index for the stroke
patients (Orgogozo et al. 1983) and the Norris index of hospital mortality (Norris et al.
1969). For the disabled patients, impairment was assessed by the patient’s GP using
existing criteria of impairment.
Disability and handicap: All patients completed the Sickness Impact Profile
(Bergner et al. 1981), the Functional Limitations Profile (Patrick and Peach 1989).
Stroke patients also completed the Barthel index (Mahoney and Barthel 1965)
which was complemented with the Observer Assessed disability (Partridge et al.
1987).
Using expert judges In order to develop separate measures of impairment, disability
and handicap, independent expert judges were asked to rate the measures as either
disability or handicap according to WHO definitions. The psychometric properties of
these new scales were then assessed for reliability and validity.
Data analysis Data was analysed to assess whether the three concepts could be
considered separate and then to examine any causal relationships between them.
Results
The results showed that the three constructs of impairment, disability and handicap
could be considered separate constructs for stroke patients but not for MI patients or
disabled adults. For the analysis of causality the focus was therefore on stroke patients.
This analysis showed that impairment did not predict disability and handicap suggesting
that there is not a simple causal progression between the different consequences of
disease. However, disability did consistently predict handicap.
Conclusions
The authors suggest that there are three possible explanations for their lack of
support for the WHO model. First, the results may relate to the measurement tools
used. Second, and relatedly the results may reflect the conceptualization of impairment.
Third, and the explanation preferred by the authors is that the WHO model is too
simplistic. The authors argue that the transition between impairment, disability and
handicap may involve a multitude of other variables not described by the model. In
particular, they suggest that the transition from initial impairment through to being
limited in social functioning may relate to psychological factors. Healthy people behave
in particular ways as a result of their beliefs and mood. The authors argue that
this is also the case for people with some form of impairment, it is just that their
impairment may influence these psychological factors. There is much variability in
the ways in which people experience and manage their illness. Psychological factors
may be a better explanation of this variation than a simple transition through a series
of stages.
OBESITY AND CORONARY HEART DISEASE 375