The validity of the SRS-22 instrument in an adult spinal deformity population compared with the Oswestry and SF-12: a study of response distribution, concurrent validity, internal consistency, and reliability.
METHODS
Prospective analysis of a consecutive cohort of adult spinal deformity patients queried over a 12-month period.


OBJECTIVE
To assess the SRS-22 instrument compared with the SF-12 and Oswestry.


BACKGROUND
Very few reports in the literature have applied the SRS-22 to adult spinal deformity patients.


METHODS
Consecutive adult spinal deformity patients were applied the SRS-22, SF-12, and Oswestry. Four analyses were done: 1) floor/ceiling effect; 2) Pearson's correlation coefficients between the SRS-22, SF-12, and Oswestry; 3) Cronbach's alpha analysis for internal consistency within the SRS-22; and 4) test/retest.


RESULTS
Floor/ceiling range for the SRS-22 compared favorably with the SF-12 and Oswestry. The Pearson's coefficients correlating the two questionnaires relative to the SRS-22 were > 0.7. The Cronbach's alpha within each domain for the SRS-22 were > 0.7, except for pain (0.67). Test/retest correlation coefficients ranged from 0.84 to 0.95 for the subscales.


CONCLUSIONS
The SRS-22 is a disease-specific instrument with the capacity to demonstrate change in health status more effectively than the SF-12 and in more domains than the Oswestry. The SRS-22 showed high criterion validity with the SF-12 and Oswestry based on Pearson's coefficients. High Cronbach's alpha scores suggested a high internal consistency within each domain of the SRS-22, except for pain (0.67). Test/retest reliability was excellent.
Bridwell
Keith H
KH
Adult Spinal Deformity Study Group, Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, MO 63110, USA. bridwellk@wustl.edu
Cats-Baril
William
W
Harrast
John
J
Berven
Sigurd
S
Glassman
Steven
S
Farcy
Jean-Pierre
JP
Horton
William C
WC
Lenke
Lawrence G
LG
Baldus
Christine
C
Radake
Terri
T
D000293:Adolescent; D000328:Adult; D000368:Aged; D000013:Congenital Abnormalities; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010147:Pain Measurement / Q000379:methods* / Q000592:standards*; D011446:Prospective Studies; D015203:Reproducibility of Results; D013116:Spinal Cord / Q000002:abnormalities* / Q000473:pathology