Discrimination validity of the scoliosis research society-22 patient questionnaire: relationship to idiopathic scoliosis curve pattern and curve size.

STUDY
DESIGN: Prospective observational study.
OBJECTIVE: To determine the discriminant validity of the Scoliosis Research Society-22 (SRS-22) health-related quality-of-life (HRQL) questionnaire for idiopathic scoliosis patients based on curve pattern and curve size. SUMMARY OF BACKGROUND DATA: An important psychometric attribute of the HRQL questionnaire is the capacity to discriminate between and among patients with differing condition severity.
METHOD: Three study groups, with subjects ranging in age from 10 to 16 years, were set up: a control group (C) of 19 persons with scoliosis suspected but unproven with an average age of 13 years; a nonsurgical group (NS) of 68 patients with an average age of 14 years and an average scoliosis (Cobb) of 30 degrees; and a presurgical group (PS) of 32 patients with an average age of 14 years and an average scoliosis of 61 degrees. The NS group was subdivided into untreated (NSU) (n = 54) and braced (NSB) patients (n = 14). Also created were subgroups of the NS and PS groups having similar curve sizes: nonsurgical similar (NSS) and presurgery similar (PSS). Statistical significance of the SRS-22 domain scores by comparison groups was tested by ANOVA. Relationships between the SRS-22 questionnaire and scoliosis deformity measurements were calculated using the Pearson Correlation Coefficients.
RESULTS: There were no significant differences between the control (C) and nonsurgical (NS) groups. The presurgical group (PS) scored significantly lower in the pain and self-image domains than the C or NS groups and lower than group C in the mental health domain. A subgroup of the nonsurgical group (NSS) with curves comparable to the presurgical subgroup (PSS) had significantly better self-image scores. There were no significant correlations between SRS-22 scores and curve pattern. For persons with scoliosis, curve size (Cobb) correlated with pain, self-image, and function; trunk asymmetry correlated with self-image.
CONCLUSION: The SRS-22 HRQL questionnaire successfully discriminated among persons with no scoliosis or moderate scoliosis and large scoliosis. It did not discriminate among patients with single, double, or triple curves. Self-image and, to a lesser extent, pain and function domain scores correlated with radiographic and trunk asymmetry severity. The SRS-22 HRQL questionnaire may be useful in choosing nonsurgical versus surgical treatment in borderline cases.