PREDICTION OF PROGRESSION OF THE CURVE IN GIRLS WHO HAVE ADOLESCENT IDIOPATHIC SCOLIOSIS OF MODERATE SEVERITY - LOGISTIC-REGRESSION ANALYSIS BASED ON DATA FROM THE BRACE STUDY OF THE SCOLIOSIS-RESEARCH-SOCIETY

In a study conducted by the Scoliosis Research Society, 159 girls with a mean age of thirteen years (range, ten to fifteen years) who had ad olescent idiopathic scoliosis were followed prospectively until skelet al maturity or until the curve had increased 6 degrees or more. All pa tients had had an initial curve of 25 to 35 degrees and an apical leve l between the eighth thoracic and first lumbar vertebrae, inclusive. O f the 159 patients, 120 were observed without treatment and thirty-nin e were managed with lateral electrical surface stimulation. The curve progressed at least 6 degrees in eighty patients. There was no apparen t difference in the outcome between the patients who were managed with observation only and those who were given electrical stimulation. Log istic regression analysis was performed to determine which of eleven f actors were predictive of progression of the scoliotic curve. A Risser sign of 0 or 1, an apical level cephalad to the twelfth thoracic vert ebra, and an imbalance of ten millimeters or less were found to be ind ependently prognostic of progression of more than 6 degrees. A prognos tic model that included these three factors and chronological age allo wed correct classification of the curve as either progressive or non-p rogressive in 81 per cent of these patients who had a thoracic or thor acolumbar adolescent idiopathic scoliosis. The positive predictive val ue was 82 per cent, the negative predictive value was 80 per cent, and the sensitivity and specificity were each 81 per cent.