Inter and intra-rater reliability of the scoliometer

Abstract

Background: the scoliometer was developed to analyze the axial rotation of the trunk in patients with idiopathic scoliosis. However, there is controversy regarding the reliability of the measures obtained with this device.

Objectives: to test the intra-rater and inter-rater reliability of the scoliometer in patients with scoliosis.

Methods: 24 volunteers of both sex with idiopathic scoliosis diagnostic (18 ± 4 years-old) and curvatures with mean and standard deviation of 24.8 ± 12.7º Cobb. The measurement procedure was accomplished in one day by two trained examiners. The palpation and determination of each spinal level was accomplished by just one examiner. Each examiner obtained one measure with the device for each vertebra from the thoracic and lumbar levels in each evaluation. For statistical analysis the measurements were divided by spinal levels into upper thorax, medium thorax, lower thorax and lumbar segments. The Intraclass Correlation Coefficient type 1,1 (ICC1,1) was used to determine the intra-rater reliability while the ICC3,1 was used to determine the inter-rater reliability.

Results: the observed intra-rater reliability values for the medium and lower thorax and lumbar segments of the subjects ranged from very good to excellent. The inter-rater reliability of the measures of axial trunk rotations was considered good to the upper thorax and excellent for the medium and lower thorax and lumbar spine.

Conclusions: the scoliometer is a device that has intra-rater reliability estimates ranging from very good to excellent. The inter-rater reliability for the upper and low thorax and for the lumbar spine is relatively lower than the intra-rater values for the same spinal segments, even when the errors from palpation and positioning of the instrument were eliminated.