5HRQOL of patients with early rheumatoid arthritis is below typical levels and that
in particular the physical aspects of HRQOL are significantly impaired compared to
the general population. PRO instruments can be designed to comprehensively assess
the overall HRQOL. Such instruments are commonly referred to as generic instru-
ments. Alternatively, PROs may be designed with a specific focus on a particular
disease, population, or aspect of HRQOL. These PROs are called specific instru-
ments [ 15 ].
Generic Instruments
Two types of generic instruments are commonly distinguished. Health profiles are
multidimensional tools with separate scales and scoring rules to assess individual
aspects of HRQOL. Health profiles aim to provide comprehensive information
regarding aspects of HRQOL that are relevant across types and severities of disease,
medical treatments, and across demographic and cultural subgroups [ 15 , 16 ].
Becasue of this, they tend to focus on nonspecific aspects of HRQOL. Probably the
most commonly used health profile across rheumatic diseases is the Short Form-
Health Survey (SF-36), which assesses HRQOL in the domains of general health,
physical functioning, bodily pain, physical role functioning, emotional role func-
tioning, social role functioning, vitality, and mental health. Other health profiles that
have, particularly in earlier times, been used in rheumatology are: (1) the Nottingham
Health Profile, which assesses the domains: energy level, pain, emotional reaction,
sleep, social isolation, and physical abilities; and (2) the Sickness Impact Profile,
which assesses the domains of somatic autonomy, mobility control and range, social
behavior, emotional stability, and psychological autonomy. As is typical for health
profiles, all three of these instruments assess domains referring to impairments, dis-
ability, and participation restrictions. A commonly cited drawback of health profiles
and generic measures in general is that they might be less responsive to change due
to their focus on general aspects of HRQOL. However, this phenomenon seems to
apply in particular to the assessment of HRQOL aspects at the participation level in
rheumatology [ 17 – 21 ].
The other types of generic instrument, utility measures of quality of life, are
grounded in health economics and reflect the preferences of patients for treatment
process and health outcome [ 15 ]. Preference-based or indirect utility measures can
be utilized to calculate quality-adjusted life years (QALYs) to be used in cost–utility
analyses. Such instruments express HRQOL as a single number along a continuum
that usually ranges fromdeath (0.0) to full health (1.0). Utility scores reflect both the
health status and the value of that health status to the patient. Utility measures are of
interest in economic analysis to justify the resources devoted to treatment. However,
they provide no information on the domains in which improvement or deterioration
occur [ 15 ].
1 PROMs and Quality of Care