Results of a study published
in The Spine Journal indicate that
the Oswestry Disability Index, Modified Swiss Spinal Stenosis Scale (SSS), and
Patient Specific Functional Scale possess adequate psychometric properties to
be used in the outcome assessment of patients with lumbar spinal stenosis.
However, further investigation is needed to validate these findings in other
samples of patients with lumbar spinal stenosis and nonspecific low back pain,
the authors add.
This cohort secondary analysis of a
randomized clinical trial of patients with lumbar spinal stenosis receiving
outpatient physical therapy included 55 patients (mean age, 69.5 years;
standard deviation, ±7.9 years; 43.1% females).
Outcome measures were the Modified Oswestry Disability
Index, SSS, Patient Specific Functional Scale, and Numeric Pain Rating Scale
(NPRS).
All patients completed the Oswestry Disability Index,
SSS, Patient Specific Functional Scale, and NPRS at the baseline examination
and at a follow-up. In addition, patients completed a 15-point Global Rating of
Change at follow-up, which was used to categorize whether patients experienced
clinically meaningful change. Changes in the Oswestry Disability Index, SSS,
Patient Specific Functional Scale, and NPRS were then used to assess
test-retest reliability, responsiveness, and minimum levels of detectable and
clinically important differences.
The Oswestry Disability Index was the only outcome
measure to exhibit excellent test-retest reliability with an intraclass correlation
coefficient of 0.86. All others ranged between fair and moderate. The Oswestry
Disability Index, SSS, and Patient Specific Functional Scale exhibited varying
levels of responsiveness, each of which was superior to the NPRS. The minimal clinically important
difference for the outcome measures for persons with lumbar spinal stenosis
were:
- Oswestry
Disability Index—5 points
- SSS— 0.36
and 0.10 for symptoms subscale and functional subscale, respectively
- Patient
Specific Functional Scale—1.3
- NPRS—1.25
for back/buttock symptoms, 1.5 for thigh/leg symptoms
APTA member Joshua
A. Cleland, PT, PhD, OCS, is the article's lead author. APTA members Julie M. Whitman, PT, T, DSc, OCS, FAAOMPT,
Robert S. Wainner, T, PhD, ECS, OCS, FAAOMPT, and John D.
Childs, PT, PhD, MBA, are coauthors.