217score minus the estimated mean for that health concept in the reference population
divided by the estimated standard deviation for the reference population. For the
purposes of this project the means and standard deviation estimates were derived
from the entire sample (that is all countries were combined and children with JIA
and healthy children were also combined). The second step is to compute the aggre-
gate summary scale scores (referred to as PhS RAW and PsS RAW) by multiplying
the standardized z -score by its factor score coeffi cients (obtained by factor analysis;
see later) and then summing the product of the 10 scales used. Finally, in the third
step each aggregate score is transformed to the norm-based PhS and PsS scores that
have a mean of 50, and a standard deviation of 10. This is done by multiplying each
aggregate summary scale score by 10 and adding the resulting product to 50. CHQ
scores were calculated using the proprietary algorithms and SAS programming code
created specifi cally for the CHQ by its author.
The Juvenile Arthritis Quality of Life Questionnaire
The Juvenile Arthritis Quality of Life Questionnaire (JAQQ) was specifi cally devel-
oped for JIA patients [ 65 ]. It consists of 74 items grouped into 4 dimensions: gross
motor function, fi ne motor function, psychosocial function, and general symptoms.
A 100 mm VAS measure of pain is also included. Only the fi ve most problematic
items in each dimension are completed and scored by each patient. A substantially
different instrument is, therefore, completed by each child. Indeed, this may com-
plicate direct comparison of results among patients for research purposes. The
JAQQ has been found to have moderate construct validity and responsiveness.
The Pediatric Rheumatology Quality of Life Scale
A shorter and simpler questionnaire for the assessment of HRQOL in routine care
of patients with rheumatic diseases, the Pediatric Rheumatology Quality of Life
Scale (PRQL) [ 69 ], was recently developed. As with the JAFS, the PRQL is cur-
rently being translated into several languages in the context of a multinational study
set to evaluate the epidemiology treatment, and outcome of JIA worldwide [ 52 ].
The PRQL is a 10-item questionnaire that explores HRQOL in two domains: physi-
cal health (PhH) and psychosocial health (PsH). It is short, simple, and quick, taking
<5 min to complete and score. It is proposed for use as both proxy report and patient
self-report, with the suggested age range of 7–18 years for use as self-report.
Validation of the parent proxy report and child self-report versions of the instrument
was accomplished by evaluating 472 JIA patients and about 800 healthy children.
As expected, both proxy- and self-reported HRQOL were found to be more impaired
in JIA patients than in healthy children, with PhH being most involved. Surprisingly,
however, the level of psychosocial well-being of JIA patients was comparable to
8 PROMs for Juvenile Idiopathic Arthritis