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objective physical fi ndings of disease. It is simple to count digital ulcers on physical
exam, or to measure pulmonary function through testing, but the intricacies of
human experience cannot be recorded from clinical assessment.
In order to confi dently utilize tools that measure PROs, they should have validity,
reliability, and sensitivity to change. If the measurement is to be trusted and used as
a part of clinical management or research trials, it must be applicable to patients
with certain features, have meaningful outcomes, and should be representative of its
stated purpose. Appropriate study of the instruments is especially required in SSc,
owing to its rarity in the general population and vast impact on the patient’s quality
of life and function.
The instruments should be accessible, easy to administer, and relevant to the
population being assessed. SSc can affect individuals of varying age, culture, lan-
guage, and education, so therefore the tools should be clear in their wording and
comprehensibility. In general, scoring should be relatively quick, straightforward,
and the score clear and meaningful.
Owing to the rarity and uniqueness of SSc, it is also important that some instru-
ments used to measure patient outcomes are specifi c to SSc. For particular aspects
of SSc, general instruments may not be suffi cient, so SSc-specifi c PROs are also
necessary. In order to compare the impact on health in SSc to other diseases, the
generic instruments may suffi ce. Many PROs can be visual analog scales (VAS) or
Likert scales (measuring change) and often they perform as well as long compli-
cated questionnaires.
Patient-Reported Outcome Measures
Considering the many possible presentations of SSc, patients experience the effects
of their disease throughout many domains of their well-being. Consequentially,
there is a multitude of possible instruments to measure PROs. These measures are
important for the evaluation and monitoring of patients with SSc and for clinical
trials regarding SSc treatment. See Table 11.1 for a chronological list of some
patient-reported outcome measures (PROMs) used in SSc.
General Measures of Functional Ability, Symptom Burden,
and Quality of Life
Health Assessment Questionnaire
In 1980, Fries et al. published the Health Assessment Questionnaire ( HAQ ) , a self-
reported measurement tool structured around fi ve core measurements: death, dis-
comfort, disability, drug toxicity, and dollar cost [ 27 ]. It was one of the fi rst measures
of PROs for rheumatic disease.
R.E. Pellar et al.