Background: Arm pain with little or no objective abnormality
(referred to herein as idiopathic arm pain) is a common and frustrating
problem for both patients and physicians. We investigated the relative effect
of idiopathic arm pain and arm pain due to a discrete diagnosis on
upper-extremity-specific health status.
Methods: The Disabilities of the Arm, Shoulder and Hand (DASH)
questionnaire was completed by 3888 patients seen over a twelve-month period.
Scores for the entire sample, for 496 patients diagnosed with idiopathic arm
pain, and for 1379 patients diagnosed with one of twenty-one discrete
conditions were compared.
Results: Patients with idiopathic pain reported substantial and
highly variable upper-limb-specific dysfunction (average DASH score [and
standard deviation], 36 ± 24 points). Patients with discrete diagnoses
also exhibited substantial variation (average standard deviation, 25; range, 6
to 27) as well as long right tails indicating floor effects, particularly for
less severe conditions (Pearson correlation of r = —0.87 between the
mean DASH score and skewness). Analysis of variance confirmed the ability of
the DASH instrument to discriminate among groups of diagnoses of varying
severity, but post hoc Tukey analysis identified ten subgroups with
substantial overlap of the DASH scores.
Conclusions: Patients with idiopathic arm pain report substantial
and highly variable upper-extremity dysfunction. The wide variations observed
in the DASH scores of the patients with idiopathic pain and those with
discrete diagnoses are greater than would be expected on the basis of the
variations in the objective pathological conditions and may reflect the strong
influence of psychological and sociological factors on health status