How should it be measured

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MEASURING HEALTH STATUS
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How should it be measured?
Unidimensional measures
Many measures focus on one particular aspect of health. For example, Goldberg (1978)
developed the general health questionnaire (GHQ), which assesses mood by asking
questions such as: ‘Have you recently: Been able to concentrate on whatever you’re
doing/Spent much time chatting to people/Been feeling happy or depressed?’ The GHQ is
available as long forms, consisting of either 30, 28 or 20 items, and a short form, which
consists of 12 items. Whilst the short form is mainly used to explore mood in general and
provides results as to an individual’s relative mood (i.e. is the person better or worse than
usual?), the longer forms have been used to detect ‘caseness’ (i.e. is the person depressed
or not?). Other unidimensional measures include the following: the hospital anxiety and
depression scale (HAD) (Zigmond and Snaith 1983) and the Beck depression inventory
(BDI) (Beck et al. 1961), both of which focus on mood; the McGill pain questionnaire,
which assesses pain levels (Melzack 1975); measures of self-esteem, such as the selfesteem scale (Rosenberg 1965) and the self-esteem inventory (Coopersmith 1967);
measures of social support (e.g. Sarason et al. 1983, 1987); measures of satisfaction
with life (e.g. Diner et al. 1985); and measures of symptoms (e.g. deHaes et al. 1990).
Therefore, these unidimensional measures assess health in terms of one specific aspect of
health and can be used on their own or in conjunction with other measures.
Multidimensional measures
Multidimensional measures assess health in the broadest sense. However, this does not
mean that such measures are always long and complicated. For example, researchers
often use a single item such as, ‘would you say your health is: excellent/good/fair/poor?’
or ‘rate your current state of health’ on a scale ranging from ‘poor’ to ‘perfect’. Further,
some researchers simply ask respondents to make a relative judgement about their health
on a scale from ‘best possible’ to ‘worst possible’. Although these simple measures do not
provide as much detail as longer measures, they have been shown to correlate highly
with other more complex measures and to be useful as an outcome measure (Idler and
Kasl 1995).
In the main, researchers have tended to use composite scales. Because of the many
ways of defining quality of life, many different measures have been developed. Some
focus on particular populations, such as the elderly (Lawton 1972, 1975; McKee et al.
2002), children (Maylath 1990), or those in the last year of life (Lawton et al. 1990).
Others focus on specific illnesses, such as diabetes (Brook et al. 1981; Bradley 1996;
Bradley et al. 1999), arthritis (Meenan et al. 1980), heart disease (Rector et al. 1993)
and renal disease (Bradley 1997). In addition, generic measures of quality of life have
also been developed, which can be applied to all individuals. These include: the Nottingham Health Profile (NHP) (Hunt et al. 1986), the short form 36 (SF36) (Ware and
Sherbourne 1992), and the sickness impact profile (SIP) (Bergner et al. 1981). All of
these measures have been criticized for being too broad and therefore resulting in a
definition of quality of life that is all encompassing, vague and unfocused. In contrast,
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