title: Inter- and intraobserver reliability assessment of the axial trunk rotation: manual versus smartphone-aided measurement tools.
abstract: BACKGROUND
  Scoliogauge, has been developed for the measurement of ATR on iPhone smartphones. This study was to evaluate the reliability for the smartphone-aided ATR measurement method and to compare its reliability with that of the manual method.
  
  
  METHODS
  Sixty-four AIS patients with single thoracic or lumbar curve participated in this study. Of these patients, thirty-two patients had main thoracic scoliosis while other thirty-two had main thoracolumbar/lumbar scoliosis. Two spine surgeons performed the measurements with Scoliometer and Scoliogauge. The Scoliogauge measurements were conducted on an iPhone 4 smartphone. The intraclass correlation coefficient (ICC) 2-way mixed model on absolute agreement was used to analyze the reliability categorized according to regions: thoracic or lumbar, and Cobb angles: <20 degrees and >40 degrees. ICC < 0.40 is considered as poor, 0.40-0.59 as fair, 0.60-0.74 as good, and 0.75-1.00 as excellent.
  
  
  RESULTS
  The overall intraobserver variability was 0.954 and the overall interobserver variability was 0.943 for the scoliometer set, whereas the intraobserver variability was 0.965 and interobserver variability was 0.964 for the scoliogauge set. Both the intraobserver and interobserver ICCs reached the excellent value in the 2 sets for both observers. The mean Cobb angle of thoracic curves in patients with main thoracic scoliosis was similar to that of lumbar curves in those with main thoracolumbar/lumbar scoliosis (35.7 degrees vs. 36.1 degrees). The intraobserver and interobserver reliability was similar between two groups (thoracic vs. lumbar) in the 2 sets. There were 21 patients having Cobb angles < 20 degrees, while 20 patients >40 degrees. The intraobserver and interobserver reliability was better in severe curve(>40 degrees) group.
  
  
  CONCLUSIONS
  Smartphone-aided measurement for ATR showed excellent reliability, and the reliability of measurement with either scoliometer or scoliogauge could be influenced by Cobb angle that reliability was better for curves with larger Cobb angles.
authors.forename: Jun
authors.initials: J
authors.lastname: Qiao
authors.forename: Leilei
authors.initials: L
authors.lastname: Xu
authors.affiliation: Spine Surgery, Drum Tower Hospital, Nanjing University Medical School, 321 Zhongshan Road, Nanjing, China. zhuzezhang@126.com.
authors.forename: Zezhang
authors.initials: Z
authors.lastname: Zhu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Liu
authors.forename: Bangping
authors.initials: B
authors.lastname: Qian
authors.forename: Yong
authors.initials: Y
authors.lastname: Qiu
mesh_terms: D000293:Adolescent; D040421:Cell Phone / Q000592:standards*; D002648:Child; D003936:Diagnosis, Computer-Assisted / Q000592:standards*; D005260:Female; D006801:Humans; D008297:Male; D015588:Observer Variation; D015203:Reproducibility of Results; D012399:Rotation; D012600:Scoliosis / Q000175:diagnosis* / Q000453:epidemiology; D060726:Torso