CONSTRUCTION AND VALIDATION OF A SPECIFIC QUALITY-OF-LIFE INSTRUMENT FOR ADOLESCENTS WITH SPINE DEFORMITIES

Design. The development and construction of a specific instrument for measuring quality of life in adolescents with spine deformities was in vestigated. Objectives. To assess the validity and reliability of the Quality of Life Profile for Spine Deformities. Summary of Background D ata, An 88-item questionnaire was self-administered to 174 patients ra nging in age from 10 to 20 years with spine deformities. Items were ra ted on a five-point Likert scale. Higher scores means high level of im pairment in quality of life. Age, gender, menarche or voice change, sa lient symptoms in the medical record, ordinary parameters on physical examination, and measurements on standard anteroposterior and lateral radiographs were recorded. The retest was done 10 days after the initi al administration in a subsample of 35 patients. Methods. The test-ret est reliability was analyzed calculating the intraclass correlation co efficient. Internal consistency was measured with the Cronbach's alpha method. Factor analysis was used to obtain a reduced number of variab les. Construct validity was assessed using the principal components mo del of factor analysis based on the correlation matrix and using the v arimax computer algorithm for orthogonal rotation. Discriminant validi ty was assessed using the Kruskal-Wallis test. Results. The Quality of Life Profile for Spine Deformities contained 21 items and five factor s in conceptual terms labeled psychosocial functioning, sleep disturba nces, back pain, body image, and back flexibility, The overall questio nnaire score showed an internal consistency of 0.88 and a test-retest correlation of 0,91, Patients with structural curves showed significan tly higher scores in all dimensions of the Quality of Life Profile for Spine Deformities except for the subscale of body image than patients with postural curves. When patients were grouped according to the sym ptom of back pain, those with backache had a significantly higher qual ity of life overall score and scores in the dimensions of sleep distur bances and pain. Brace-treated patients showed statistically significa nt differences in the quality of life overall score and scores in the dimensions of psychosocial functioning and back flexibility. Conclusio ns, The instrument developed for measuring quality of life in patients with spine deformities during the period of bone growth has validity, internal consistency, and high test-retest reliability. The conceptua lization of quality of life of the Quality of Life Profile for Spine D eformity includes psychosocial dimensions and pain and function.