Article

Comparative effectiveness research (CER) requires valid outcome
measures that discriminate patients by risk factors in similar ways across
settings. Standardized functional status (FS) measures in physical therapy are
used routinely in multiple countries, creating the potential for CER among countries.
The purpose of this study was to assess known-groups
construct validity of a knee-specific FS measure within and between 2 countries
for patients receiving outpatient physical therapy due to knee impairments.
DESIGN: This was a longitudinal, observational cohort study. METHODS: The
participants were 4,972 and 2,964 adult (age >/=18 years) patients with knee
impairments from Israel and the United States, respectively. Differences in
patient characteristics between the 2 countries were assessed using chi-square
statistics and 2-sample t tests, as appropriate. Known-groups validity within and
between the countries was assessed using 2-way analysis of covariance predicting
FS at discharge, with sex, age, symptom acuity, surgical and exercise history,
intake medication use, and country as risk-adjustment factors. Intake FS was the
covariate. To compare how FS discriminated patient groups between countries, each
factor was tested separately with models including an interaction term between
the factor and country. RESULTS: Patients were different between countries but
had similar discharge FS trends, including: higher outcomes in patients who were
male, were younger, had acute conditions, had one surgical procedure related to
their knee impairment, were more physically active, and did not use related
medication at admission. Interactions were not significant for sex, symptom
acuity, and exercise history but were significant for age, surgical history, and
medication use. Limitations Although strict patient selection criteria were set,
some patient selection bias still might have existed.
CONCLUSIONS: The results
demonstrated the knee FS measures would be valid for use in CER between Hebrew-speaking patients (Israel) and English-speaking patients (United States).

Langue : ANGLAIS