International utilization of the SRS-22 instrument to assess outcomes in adolescent idiopathic scoliosis: what can we learn from a medical outreach group in Ghana?

BACKGROUND: Cross-cultural studies on adolescent idiopathic scoliosis (AIS) populations are limited. This study evaluated the discriminate validity of the Scoliosis Research Society Questionnaire (SRS-22) in Ghana between adolescents with and without AIS. SRS-22 outcomes from AIS and normal adolescents in Ghana were also compared with scores from AIS and normal adolescents in America.
METHODS: A retrospective review of preoperative SRS-22 questionnaires from Ghana and New York City was completed. In Ghana, 84 adolescents without scoliosis (healthy-G) (32 female adolescents; mean age, 13.3 y) and 61 patients with AIS (AIS-G) (76 female adolescents; mean age, 15.4 y) were administered with the SRS-22 questionnaire. From the New York City, 450 healthy adolescents (healthy-US) (279 female adolescents; mean age, 16 y) and 302 patients with AIS (AIS-US) (227 female adolescents; mean age, 14.9 y) also completed the SRS-22 questionnaire. Patients with curve magnitudes <40 (nonoperative) were then excluded. All 4 groups were matched based on age and sex, resulting in 4 groups of 40 subjects (25 female adolescents; mean age, 14.5 y for all groups). Differences in SRS-22 scores across the groups were analyzed using analysis of variance and analysis of covariance, with the Bonferroni post hoc tests, to control for differences in curve magnitude.
RESULTS: Mean curve magnitude for the matched groups was larger for the AIS-G group [67.2 degrees (range, 42 to 130 degrees)] as compared with the AIS-US group [52 degrees (range, 40 to 76 degrees)] (P<0.01). When controlling for the curve magnitude, a significant difference between all 4 study groups was found within all domains and total score (P<0.01). AIS-G displayed significantly lower scores in the activity, image, pain, and mental health domains (P<0.01); this reached the minimal clinically importance difference for these domains. Healthy-US and healthy-G had better overall and domain-specific scores than AIS-US and AIS-G, respectively (P<0.05).
CONCLUSIONS: These findings illustrate the affect of AIS within a culture as well as across cultures. Healthy adolescents had significantly better scores than scoliotic adolescents. Ghanaian adolescents had significantly worse Health-Related Quality-of-Life scores than American adolescents, especially those suffering from AIS. These differences should be kept in mind by those treating this already emotionally vulnerable adolescent population. LEVEL OF EVIDENCE: Level II Prognostic.