Background: The purpose of this study was
to determine whether currently published outcome measures of physical
function would be suitable for use for older adults with a hip fracture.
The measures that were considered were the Musculoskeletal Function
Assessment (MFA) Instrument, the Older Americans' Resources and
Services (OARS) Multidimensional Functional Assessment Questionnaire
physical function subscale, the Toronto Extremity Salvage Score
(TESS), and the Short Form-36 (SF-36). Following suggestions by
an expert panel and patient interviews, the MFA was not tested further.
The TESS was modified and renamed the Lower Extremity Measure (LEM).
Methods: Forty-three community-dwelling patients
with a hip fracture completed the LEM, OARS, and SF-36 in the hospital
so that the prefracture status could be obtained; they were then
followed prospectively at six weeks and at six months. All patients
were interviewed twice in the hospital to assess the reliability
of the LEM (intraclass correlation coefficient = 0.85). To establish
criterion validity, the measures were compared with the Timed Up
and Go (TUG) test at six weeks. We tested a number of hypotheses
to determine construct validity.
Results: Only the LEM scores were significantly
correlated with the TUG scores (r = -0.53, p = 0.03). The LEM scores
were significantly correlated with the SF-36 subscale scores and
the OARS scores. Patients with at least one comorbidity had a lower mean
prefracture LEM score (90.0 ±9.7) than patients
with no comorbidity (96.9 ±8.1) (p = 0.02).
Patients who had used no walking aids before the fracture had a
higher mean prefracture LEM score than those who had used a cane (95.5 ± 5.8 compared with 85.5 ±12.7;
p = 0.0007). Both the LEM and the SF-36 scores changed significantly
between all of the time-periods (p < 0.05). Measures of responsiveness
indicated that the LEM was the best measure for detecting changes
in physical function.
Conclusions: The LEM can detect clinically important
changes in physical function over time in patients with a hip fracture
and would be most useful for clinical trials or cohort studies.
Orthopaedists who are currently utilizing the SF-36 can be reassured
that the physical function subscale is a valid measure for patients
with a hip fracture.