Article

OBJECTIVE: To assess and compare the validity of six physical function measures
in people awaiting hip or knee joint replacement. DESIGN: Eighty-two people
awaiting hip or knee replacement were assessed using six physical function
measures including the WOMAC Function scale, SF-36 Physical Function scale, SF-36
Physical Component Summary scale, Patient Specific Functional Scale, 30-second
chair stand test, and 50-foot timed walk. Validity was assessed using a
head-to-head comparison design. RESULTS: Convergent validity was demonstrated
with significant correlations between most measures (Spearman's rho 0.22 to
0.71). The Patient Specific Functional Scale had the lowest correlations with
other measures of physical function. Discriminant validity was demonstrated with
low correlations between mental health and physical function scores (Spearman's
rho -0.12 to 0.33). Only the WOMAC Function scale, 30-second chair stand test,
and 50-foot timed walk demonstrated known groups validity when scores for
participants who walked with a gait aid were compared with those who did not.
Standardized response means and Guyatt's responsiveness indexes indicated that
the SF-36 was the least responsive measure. CONCLUSIONS: For those awaiting joint
replacement surgery of the hip or knee, the current investigation found that the
WOMAC Function scale, 30-second chair stand test, and 50-foot timed walk
demonstrated the most evidence of validity. The Patient Specific Functional Scale
might complement other measures by capturing a different aspect of physical
function.

Langue : ANGLAIS