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Published on: February 5, 2011
Inter-Rater Reliability of Collateral Status Assessment Based on CT Angiography: A Retrospective Study of Middle
Daria D Dolotova1,2, Evgenia R Blagosklonova2, Rustam Sh Muslimov3
1Department of Bioinformatics, Department of Pediatric Surgery, Pirogov Russian National Research Medical University, Russian Ministry of Health, 117997 Moscow, Russia.
Insights
Assessing collateral status (CS) in ischaemic stroke (IS) is crucial. This study found moderate inter-rater reliability for three CS scales, with the modified Tan scale showing the highest consistency, though not statistically significant.
Area of Science:
- Neurology
- Radiology
- Medical Imaging
Background:
- Clinical guidelines emphasize assessing collateral status (CS) in ischaemic stroke (IS) patients.
- Existing qualitative/semiquantitative scales for CS assessment based on CTA images have limited reported inter-rater reliability.
- Standardized and reliable collateral assessment is vital for guiding treatment decisions in IS.
Purpose of the Study:
- To investigate and compare the inter-rater reliability of three commonly used scales for collateral assessment in acute ischaemic stroke.
- To evaluate the modified Tan scale, Miteff scale, and Rosenthal scale for their consistency among raters.
- To determine if any scale demonstrates superior reliability for collateral status evaluation.
Main Methods:
- Retrospective analysis of CT Angiography (CTA) images from 158 patients with acute IS.
- Two independent experts assessed collateral status using the modified Tan, Miteff, and Rosenthal scales.
- Inter-rater reliability was quantified using Cohen's kappa, weighted kappa, and Krippendorff's alpha.
Main Results:
- Weighted kappa values for the modified Tan, Miteff, and Rosenthal scales were 0.72, 0.49, and 0.59, respectively.
- The modified Tan scale demonstrated the highest consistency, but no statistically significant differences in reliability were found among the three scales.
- The modified Tan and Rosenthal scales showed a significant impact of CS on the degree of neurological deficit at discharge.
Conclusions:
- The study indicates a moderate level of inter-rater reliability for the evaluated collateral assessment scales in acute IS.
- While the modified Tan scale showed better consistency, none of the scales could be definitively identified as superior based on this reliability analysis.
- Further research may be needed to refine or develop more reliable methods for collateral status assessment in IS.
Abstract:
The importance of assessing the collateral status (CS) in patients with ischaemic stroke (IS) has repeatedly been emphasised in clinical guidelines. Various publications offer qualitative or semiquantitative scales with gradations corresponding to the different extents of the collaterals, visualised mostly on the basis of CTA images. However, information on their inter-rater reliability is limited. Therefore, the aim of this study is to investigate the inter-rater reliability of the scales for collateral assessment. CTA images of 158 patients in the acute period of IS were used in the study. The assessment of CS was performed by two experts using three methodologies: the modified Tan scale, the Miteff scale, and the Rosenthal scale. Cohen's kappa, weighted kappa and Krippendorff's alpha were used as reliability measures. For the modified Tan scale and the Miteff and Rosenthal scales, the weighted kappa values were 0.72, 0.49 and 0.59, respectively. Although the best measure of consistency was found for the modified Tan scale, no statistically significant differences were revealed among the scales. The impact of the CS on the degree of neurological deficit at discharge was shown for the modified Tan and Rosenthal scales. In conclusion, the analysis showed a moderate inter-rater reliability of the three scales, but was not able to distinguish the best one among them.
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