A Practical Study of Diagnostic Accuracy

Scoliosis Screenings of Middle School Students by a Trained Nurse With a Smartphone Versus a Spine Surgeon With a Scoliometer

Chao Chen, MD; Ronghua Yu, MD; Wei Xu, MD; Zhikun Li, MD; Yifan Li, MD; Ruixi Hu, MB; Xiaodong Zhu, MD, PhD


Spine. 2020;45(5):E266-E271. 

In This Article

Abstract and Introduction


Study Design: Cross-sectional.

Objective: This study aimed to assess the accuracy of smartphone-aided diagnosis of scoliosis by a trained nurse compared with scoliometer-based diagnosis by a spine surgeon.

Summary of Background Data: Many assessments have been developed to estimate the reliability of smartphone-aided measurements in diagnosing scoliosis. However, clinical studies assessing the accuracy of smartphone-aided diagnosis with radiographs or scoliometers are scarce.

Methods: A total of 2702 grade 7 students (mean age 13.56 yrs, range 13–15) at 10 middle schools were first screened with a smartphone by a trained nurse from the orthopedics department. Approximately half a year later, most of the students underwent a chest x-ray examination as part of a compulsory medical examination. Students with suspicious findings in either the first screen or the chest x-ray were recommended to a scoliosis clinic for single-blind tests, such as a forward bending test (FBT) and an analysis of the angle of trunk rotation (ATR) with a scoliometer, performed by an experienced spine surgeon. Finally, the Cobb method was conducted with full-spine radiographs to serve as the gold standard.

Results: The agreement between the first screening by the nurse and the second test by the spine surgeon was low in cases with a Cobb angle <10° (κ = 0.128 [0.04–0.22], P = 0.035) and fair in cases with a Cobb angle >10° (κ = 0.349 [0.19–0.50], P < 0.001). The results of receiver operating characteristic (ROC) curve analysis also suggested that these two tests were similar in their ability to diagnose scoliosis. However, when the Cobb angle cutoff was adjusted to 15°, the latter had markedly better diagnostic ability than the former. Overall, the sensitivity of the smartphone screening was not acceptable for recognizing scoliosis.

Conclusion: This study revealed that smartphone-aided screening for scoliosis is risky.

Level of Evidence: 3


Adolescent idiopathic scoliosis (AIS) is a common deformity in adolescents and affects girls more often than boys during their physiologic growth. Since brace treatment is effective in stopping the curve from progressing,[1,2] early recognition of scoliosis is crucial. The Cobb method is considered the gold standard in scoliosis diagnosis,[3] but full-spine radiographs as a screening method for all adolescents are not advocated because of the low rate of morbidity, and excess x-ray doses may endanger children's vulnerable organs; as an alternative, most negative cases can be identified without x-rays.[4] The Adams forward bending test (FBT) combined with a scoliometer has been accepted as the optimal method of AIS screening in students, with predictive values of 29% to 54%.[5] Although moiré topography assessment has a higher predictive value than the FBT, the specialized equipment for the former is unavailable for preliminary screening, which limits its feasibility.[6]

Currently, the majority of smartphones contain integrated inclinometers to evaluate inclination in everyday use. It would be economical and convenient if scoliosis screening could be performed at home by measuring the angle of trunk rotation (ATR) with a smartphone. However, whether smartphones can be generally used in scoliosis screening is still under debate for several reasons, one of which is because the phones are not designed to avoid contact with the spinal processes. In addition, the examiner's professional background may affect the reliability of measurement. Variability usually occurs among examiners because the position of the instrument and the determination of the spinous processes can greatly influence the results. Several studies have been designed to test the effectiveness of smartphones in measuring the ATR.[7–9] However, these studies evaluated only the intraobserver and interobserver angular accuracy of the app, and no practical application has been achieved, leaving the clinical value of this method in question. Therefore, a cross-sectional study was conducted to evaluate whether the use of a smartphone by trained personnel is sufficient for the screening task.