215Other Measures of Physical Function
Other validated tools for the assessment of functional ability in JIA patients include
the Juvenile Arthritis Functional Assessment Scale (JAFAS) , Juvenile Arthritis
Functional Assessment Report (JAFAR), and the Juvenile Arthritis Self-Report
Index (JASI). Developed in 1989, the JAFAS is an observer-based scale, which
requires a trained observer and standardized equipment, and is based on timing on 10
physical tasks [ 53 ]. The JAFAR assesses the ability of children older than 7 years to
perform physical tasks in 23 items; 2 versions are available, 1 for children (JAFAR-C)
and 1 for parents (JAFAR-P) [ 54 ]. Finally, the JASI is a 100-item instrument that
explores physical function in fi ve domains. It is a very comprehensive, valid, and
reliable tool, although it requires a long time to be completed [ 55 ]. The JASI is
unique in that item generation took place through interviews with children, parents,
teachers, and clinicians, although only the clinicians conducted item reduction.
To overcome the potential bias in answering that may be provided by subjective
assessment of physical function, which can be infl uenced by level of understanding
and emotional background of questionnaire completer, Iglesias and coworkers [ 56 ]
designed an observational functional ability scale: the CAPFUN (capacidad funcio-
nal = functional ability). It consists of 20 items that assess 10 activities in the upper
limbs or cervical spine and 10 in the lower limbs. Each item is scored as 0 when it
is impossible to perform, as 1 when it is performed incompletely or with diffi culty,
and as 2 when it is well performed. The mean value of upper and lower limb scores
is added and their mean value, which ranges from 0 to 2, is defi ned as the CAPFUN
score. This tool, which has the advantage of providing an objective assessment of
physical function, revealed good internal reliability and construct validity.
Health-Related Quality of Life
HRQOL is a multidimensional concept that incorporates measures of physical
symptoms, functional status, and disease impact on psychological and social func-
tioning [ 4 , 39 – 41 , 57 – 60 ]. JIA is a disease that infl uences all aspects of a child’s life
at a physical, social, and intellectual level [ 1 , 61 ]. In chronic conditions such as JIA
where mortality is not a major factor, HRQOL often serves as a primary measure of
patient outcome. However, HRQOL should be defi ned, characterized, and measured
in an appropriate way for it to be clinically useful.
In recent years, a number of HRQOL measures have been developed for use in
children and are usually divided into 2 types: (1) disease-specifi c measures [ 14 ,
62 – 65 ], which are centered on a particular disease such as JIA and (2) generic,
which measure quality of life independent of the underlying disease [ 66 , 67 ].
8 PROMs for Juvenile Idiopathic Arthritis