These data provide both validation and st and ards for other users and indicate the power of the instrument for detecting change in sample population s. CONCLUSIONS The  ODI  remains a valid and vigorous measure and has been a worthwhile outcome measure .
The behavior of the instrument is incompletely understood , particularly in sensitivity to real change
STUDY DESIGN The Oswestry Disability Index ( ODI ) has become one of the principal condition-specific outcome measures used in the management of spinal disorders .
This review is based on publications using the ODI identified from the authors ' personal data bases , the Science Citation Index , and h and search es of Spine and current textbooks of spinal disorders .
OBJECTIVES To review the versions of this instrument , document methods by which it has been vali date d , collate data from scores found in normal and back pain population s , provide curves for power calculations in studies using the ODI , and maintain the ODI as a gold st and ard outcome measure .
SUMMARY OF BACKGROUND DATA It has now been 20 years since its original publication .
More than 200 citations exist in the Science Citation Index .
Lumbar spinal stenosis: assessment of long-term outcome 12 years after operative and conservative treatment.
The present study focuses on the long-term prognosis of radiographically verified stenosis of the lower lumbar spine . The purpose here was to describe the outcome 12 years after radiographic diagnosis of spinal stenosis and to identify factors predicting disability after operative or conservative treatment . Data were compiled on 75 patients ( 43 men and 32 women ) with changes in functional myelography diagnostic for spinal stenosis . Their mean age at the interview 12 years later was 61 years .  The sagittal diameter of the dural sac was measured from baseline myelographs at all intervertebral levels and was corrected for magnification . In the interview , subjective outcome assessment was obtained with a structured question naire , and the low-back disorder was scored using the Oswestry disability index . The sagittal diameter of the dural sac was severely stenotic ( < 7.0 mm ) in 32 patients ( 26 operated ) , and moderately stenotic ( 7.0 - 10.5 mm ) in 43 patients ( 31 operated ) . The severity of the stenosis significantly predicted disability , even when the effects of age , sex , therapy regimen , and body mass index were adjusted for . For moderate and severe stenosis , the adjusted mean Oswestry indices were 28.4 and 39.1 , respectively ( p = 0.01 ) . Therapy as such ( operative versus nonoperative ) did not significantly correlate with later disability . The radiographic severity of lumbar spinal stenosis predicts disability independently of therapy regimen . R and omized clinical trials are needed to establish the indications for surgical and conservative treatment . Radiographic severity of the stenosis should be considered as an effect-modifying or confounding factor in clinical trials and other studies focusing on the outcome of lumbar spinal stenosis
These data provide both validation and st and ards for other users and indicate the power of the instrument for detecting change in sample population s. CONCLUSIONS The  ODI  remains a valid and vigorous measure and has been a worthwhile outcome measure .
The behavior of the instrument is incompletely understood , particularly in sensitivity to real change
STUDY DESIGN The Oswestry Disability Index ( ODI ) has become one of the principal condition-specific outcome measures used in the management of spinal disorders .
This review is based on publications using the ODI identified from the authors ' personal data bases , the Science Citation Index , and h and search es of Spine and current textbooks of spinal disorders .
OBJECTIVES To review the versions of this instrument , document methods by which it has been vali date d , collate data from scores found in normal and back pain population s , provide curves for power calculations in studies using the ODI , and maintain the ODI as a gold st and ard outcome measure .
SUMMARY OF BACKGROUND DATA It has now been 20 years since its original publication .
More than 200 citations exist in the Science Citation Index .