Background: Many patient-based knee-rating scales
are available for the evaluation of athletic patients. However,
there is little information on the measurement properties of these
instruments and therefore no evidence to support the use of one
questionnaire rather than another. The goal of the present study
was to determine the reliability, validity, and responsiveness of
four knee-rating scales commonly used for the evaluation of athletic
patients: the Lysholm scale, the subjective components of the Cincinnati
knee-rating system, the American Academy of Orthopaedic Surgeons
sports knee-rating scale, and the Activities of Daily Living scale
of the Knee Outcome Survey.
Methods: All patients in the study had a disorder
of the knee and were active in sports (a Tegner score of 4 points).
Forty-one patients who had a knee disorder that had stabilized and
who were not receiving treatment were administered all four questionnaires
at baseline and again at a mean of 5.2 days (range, two to fourteen
days) later to test reliability. Forty-two patients were administered
the scales at baseline and at a minimum of three months after treatment
to test responsiveness. The responses of 133 patients at baseline
were studied to test construct validity.
Results: The reliability was high for all scales,
with the intraclass correlation coefficient ranging from 0.88 to
0.95. As for construct validity, the correlations among the knee
scales ranged from 0.70 to 0.85 and those between the knee scales
and the physical component scale of the Short Form-36 (SF-36) and the
patient and clinician severity ratings ranged from 0.59 to 0.77.
Responsiveness, measured with the standardized response mean, ranged
from 0.8 for the Cincinnati knee-rating system to 1.1 for the Activities
of Daily Living scale.
Conclusions: All four scales satisfied our criteria
for reliability, validity, and responsiveness, and all are acceptable
for use in clinical research.