Ten-year follow-up evaluation of a school screening program for scoliosis - Is the forward-bending test an accurate diagnostic criterion for the screening of scoliosis?

Study Design. A 10-year follow-up evaluation of the effectiveness of school screening for scoliosis performed in a closed island population. Objectives. To evaluate the diagnostic accuracy of methods used for screeni ng scoliosis and to re-examine the long-term effectiveness of the school sc oliosis screening program. Summary of Background Data. The diagnostic accuracy of the forward-bending test and the long-term efficacy of the screening programs have not been cle arly established. Methods. In 1987, 2700 pupils aged 8 to 16 years from the island of Samos w ere screened for scoliosis. The Adams forward-bending lest, Moire topograph y, the scoliometer, and the humpometer were used. Radiologic evaluation of the spine was available for each pupil and the number of false-negative and false-positive results of the screening methods was calculated. Subsequent ly, sensitivity, specificity, and positive and negative predictive values w ere estimated for each screening technique. Pupils found positive for spina l deformity were then followed up regularly at yearly intervals. In 1997, a ll positive subjects attended a 10-year clinical and radiologic followup, a nd the remaining subjects were re-evaluated by a postal questionnaire and w ere clinically examined if necessary. Results. Spinal deformity was found in 153 (5.66%) pupils. Scoliosis (defin ed as a spinal curvature greater than or equal to 10 degrees) was found in 32 pupils, for a prevalence of 1.18%. For scoliosis, the Adams forward-bend ing test showed a number of false-negative results tin five cases), for a s ensitivity of 84.37% and specificity of 93.44%. The sensitivities of Moire topography, the humpometer, and the scoliometer were 100%, 93.75%, and 90.6 2%, respectively, and specificity was 85.38%, 78.11%, and 79.76% respective ly. The negative predictive value of the forward-bending test was inferior to those of the other methods. During this scoliosis screening program, if cutoff limits for referral had been used, such as the asymmetry of two Moir e fringes, a humpogram deformity of (D+H) = 10 mm, and 8 degrees of scoliom eter angle, it would have been possible to reduce radiologic examination by 89.4%. Three (0.11%) pupils aged between 12 and 14 years with scoliotic de formities greater than 20 degrees underwent satisfactory nonoperative treat ment with Boston braces. One pupil with a 40 degrees thoracic curvature, un derwent satisfactory surgical treatment because of progression 1 year later . Of the 121 spinal deformities with an initial Cobb angle less than 10 deg rees, 44 (35.8%), and of the 29 scoliotic deformities with an initial Cobb angle between 10 degrees and 20 degrees, 14 (48.3%) progressed (a Cobb angl e difference of at least 5 degrees in more than one examination). Observati on and physiotherapy were the only treatments applied to all except one of the pupils in these groups. Conclusions. The Adams forward-bending test cannot be considered a safe dia gnostic criterion for the early detection of scoliosis (especially when it is used as the only screening tool) because it results in an unacceptable n umber of false-negative findings. For the early detection of scoliosis, a c ombination of back-shape analysis methods can be safely used with the intro duction of cutoff limits for referral being a useful procedure. The inciden ce of significant scoliosis is low, and its natural history seems to be ind ependent of early detection. The widespread use of school scoliosis screeni ng with the use of the forward-bending test must be questioned.