Outcome measures
The primary task of the expert advisory panel of WHO that
worked on the low back pain initiative was to try to determine
how to assess improvement of back pain, by defining
outcome measures relevant to all cultures (1). The purpose
of the deliberations was to ensure uniformity of reporting,
and, to that end, the extant examinations and tests were evaluated
and applied in studies in various parts of the world,
translated into local languages, and back-translated to assure
that the import of the questions was not lost. The basic
measures need to be included in comparative studies, but
investigators obviously are free to add others if they wish.
The history of the complaint and the physical examination
were determined to be central: the only additional physical
measure considered useful was a modified Schober test of
spinal mobility. Other favourite examination techniques
failed universality. In addition, for the purpose of studies,
severity of pain should be measured with a visual analogue
scale (preferably one with a single line rather than with
demarcations that would give rise to regressions to the
mean). The Oswestry disability questionnaire, a modified
Zung questionnaire, and a modified somatic perception
questionnaire were considered appropriate measurements
after 21 other commonly-used assessments were found to
lack universality. Studies were carried out on all six continents
to ascertain their applicability. Although these recommendations