Classification of Early Onset Scoliosis (C-EOS) Has Almost Perfect Inter and Intra Observer Reliability
• Micaela Cyr, BA• Tricia St. Hilaire, MPH• Zhaoxing Pan, PhD• George H. Thompson, MD• Children’s Spine Study Group• Growing Spine Study Group• Sumeet Garg, MD
Classification of Early Onset Scoliosis (C-EOS)
Williams, B.A., et al., Development and Initial Validation of the Classification of Early-Onset Scoliosis (C-EOS). The Journal of Bone & Joint Surgery, 2014. 96(16): p. 1359-1367
Purpose
• To evaluate the inter-observer and intra-observer reliability of the Classification of Early Onset Scoliosis (C-EOS) scheme
Methods• 50 patient cases drawn from registry
and used to create online survey
• Survey sent to faculty, research coordinators, fellows involved with CSSG and GSSG
• Surveys sent twice to test intra-observer reliability
Methods
Kappa value
Degree of agreement
<=0 Poor
0-0.2 Slight
0.2 - 0.4 Fair
0.4 - 0.6 Moderate
0.6 - 0.8 Substantial
0.8 - 1 Almost perfect
• Fleiss Kappa and Cohen’s Kappa used to asses inter-observer and intra-observer reliability respectively
• Hypothesis: All categories would have Kappa value 0.75 or higher
Results• 36 total participants, 29
completed twice
• Overall Fleiss Kappa for inter-observer reliability was almost perfect for etiology (0.84), Cobb angle (0.93), kyphosis angle (0.96)
Inter-observer reliability
Etiology Cobb Angle Kyphosis Angle0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
10.9 0.91
0.96
0.78
0.95 0.96
Faculty Research Coordinators
Fleis
s K
appa V
alu
e
Intra-observer reliability
• Overall Cohen’s Kappa for intra-observer reliability was almost perfect for etiology (0.92), Cobb angle (0.96), kyphosis angle (0.98)
• Intra-observer reliability was almost perfect across all major categories for all groups
Conclusions• Etiology most difficult to classify, still
demonstrates high reliability
• High reliability with minimal training, varying degrees of familiarity with the system
• C-EOS can be used as a reliable tool
References• 1. Lenke, L.G., et al., Adolescent idiopathic scoliosis a new classification to
determine extent of spinal arthrodesis. The Journal of Bone & Joint Surgery, 2001. 83(8): p. 1169-1181.
• 2. Clavien, P.A., et al., The Clavien-Dindo classification of surgical complications: five-year experience. Annals of surgery, 2009. 250(2): p. 187-196.
• 3. Sink, E.L., et al., Reliability of a complication classification system for orthopaedic surgery. Clinical Orthopaedics and Related Research®, 2012. 470(8): p. 2220-2226.
• 4. Williams, B.A., et al., Development and Initial Validation of the Classification of Early-Onset Scoliosis (C-EOS). The Journal of Bone & Joint Surgery, 2014. 96(16): p. 1359-1367.
• 5. Park, H.Y. The Classification for Early Onset Scoliosis (C-EOS) Predicts Timing of VEPTR Anchor Failure. in 2013 AAP National Conference and Exhibition. 2013. American Academy of Pediatrics.
• 6. Cummings, R.J., et al., Interobserver Reliability and Intraobserver Reproducibility of the System of King et al. for the Classification of Adolescent Idiopathic Scoliosis*. The Journal of Bone & Joint Surgery, 1998. 80(8): p. 1107-11.
• 7. Fleiss, J.L., B. Levin, and M.C. Paik, Statistical methods for rates and proportions. 2013: John Wiley & Sons.
• 8. Cohen, J. A coefficient of agreement for nominal scales. Educational and Psychological Measurement, 1960. 20(1): p. 37-46.
• 9. Landis, J.R. and G.G. Koch, The measurement of observer agreement for categorical data. biometrics, 1977: p. 159-174.
