High inter-rater reliability, agreement, and convergent validity of Constant score in patients with clavicle fractures

TY - JOUR

T1 - High inter-rater reliability, agreement, and convergent validity of Constant score in patients with clavicle fractures

AU - Ban, Ilija

AU - Troelsen, Anders

AU - Kristensen, Morten Tange

N1 - Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

PY - 2016/10/1

Y1 - 2016/10/1

N2 - BACKGROUND: The Constant score (CS) has been the primary endpoint in most studies on clavicle fractures. However, the CS was not developed to assess patients with clavicle fractures. Our aim was to examine inter-rater reliability and agreement of the CS in patients with clavicle fractures. The secondary aim was to estimate the correlation between the CS and the Disabilities of the Arm, Shoulder and Hand score and the internal consistency of the 2 scores.METHODS: On the basis of sample sizing, 36 patients (31 male and 5 female patients; mean age, 41.3 years) with clavicle fractures underwent standardized CS assessment at a mean of 6.8 weeks (SD, 1.0 weeks) after injury. Reliability and agreement of the CS were determined by 2 raters. The interclass correlation coefficient (ICC2,1), standard error of measurement, minimal detectable change, Cronbach α coefficient, and Pearson correlation coefficient were estimated.RESULTS: Inter-rater reliability of the total CS was excellent (interclass correlation coefficient, 0.94; 95% confidence interval, 0.88-0.97), with no systematic difference between the 2 raters (P = .75). The standard error of measurement (measurement error at the group level) was 4.9, whereas the minimal detectable change (smallest change needed to indicate a real change for an individual) was 13.6 CS points. The internal consistency of the 10 CS items was good, with a Cronbach α of .85, and we found a strong correlation (r = -0.92) between the CS and Disabilities of the Arm, Shoulder and Hand score.CONCLUSIONS: The CS was found to be reliable for assessing patients with clavicle fractures, especially at the group level. With high inter-rater reliability and agreement, in addition to good internal consistency, the standardized CS used in this study can be used for comparison of results from different settings.

AB - BACKGROUND: The Constant score (CS) has been the primary endpoint in most studies on clavicle fractures. However, the CS was not developed to assess patients with clavicle fractures. Our aim was to examine inter-rater reliability and agreement of the CS in patients with clavicle fractures. The secondary aim was to estimate the correlation between the CS and the Disabilities of the Arm, Shoulder and Hand score and the internal consistency of the 2 scores.METHODS: On the basis of sample sizing, 36 patients (31 male and 5 female patients; mean age, 41.3 years) with clavicle fractures underwent standardized CS assessment at a mean of 6.8 weeks (SD, 1.0 weeks) after injury. Reliability and agreement of the CS were determined by 2 raters. The interclass correlation coefficient (ICC2,1), standard error of measurement, minimal detectable change, Cronbach α coefficient, and Pearson correlation coefficient were estimated.RESULTS: Inter-rater reliability of the total CS was excellent (interclass correlation coefficient, 0.94; 95% confidence interval, 0.88-0.97), with no systematic difference between the 2 raters (P = .75). The standard error of measurement (measurement error at the group level) was 4.9, whereas the minimal detectable change (smallest change needed to indicate a real change for an individual) was 13.6 CS points. The internal consistency of the 10 CS items was good, with a Cronbach α of .85, and we found a strong correlation (r = -0.92) between the CS and Disabilities of the Arm, Shoulder and Hand score.CONCLUSIONS: The CS was found to be reliable for assessing patients with clavicle fractures, especially at the group level. With high inter-rater reliability and agreement, in addition to good internal consistency, the standardized CS used in this study can be used for comparison of results from different settings.

KW - Adult

KW - Clavicle

KW - Cross-Sectional Studies

KW - Disability Evaluation

KW - Female

KW - Fractures, Bone

KW - Humans

KW - Male

KW - Muscle Strength

KW - Patient Outcome Assessment

KW - Prospective Studies

KW - Reproducibility of Results

KW - Visual Analog Scale

KW - Journal Article

KW - Validation Studies

U2 - 10.1016/j.jse.2016.02.022

DO - 10.1016/j.jse.2016.02.022

M3 - Journal article

C2 - 27106115

SN - 1058-2746

VL - 25

SP - 1577

EP - 1582

JO - Journal of Shoulder and Elbow Surgery

JF - Journal of Shoulder and Elbow Surgery

IS - 10

ER -