Validation of the Danish version of the McGill Ingestive Skills Assessment using classical test theory and the Rasch model

Abstract

Purpose: The study aimed to validate the Danish version of the Canadian the “McGill Ingestive Skills Assessment” (MISA-DK) for measuring dysphagia in frail elders. Method: One-hundred and ten consecutive older medical patients were recruited to the study. Reliability was assessed by internal consistency (Chronbach’s alpha). External construct validity (convergent and known-groups validity) was evaluated against theoretical constructs assessing the complex concept of ingestive skills. Internal construct validity was tested using Rasch analysis. Results: High internal consistency reliability with Chronbach’s alpha of 0.77–0.95 was evident. External construct validity was supported by expected high correlations with most of the constructs related to ingestive skills (r_s = 0.53 to r_s = 0.66). The MISA-DK discriminated significantly between known-groups. Fit to the Rasch model (x² (df) = 12 (12), p = 0.424) and unidimensionality of the MISA-DK was confirmed after resolving disordered thresholds for 11 items and adjustment of local dependency. Conclusion: The psychometric properties of the MISA-DK equal the original Canadian version. Assessment of internal construct validity indicated multidimensionality due to local dependency. Although achieving good fit to the Rasch model after adjustments, additional studies are needed to establish cross-cultural validity. Finally, establishment of the inter- and intra-rater reliability of the MISA-DK is also needed.

Implications for Rehabilitation

• Validity evidence is a prerequisite to verify whether a measurement instrument in fact accomplish what it is supposed to accomplish.

• Using classical test theory in combination with the Rasch Model provides comprehensive insight of validity evidence.

• The Danish version of the McGill Ingestive Skills Assessment provides valid estimates of dysphagia patients’ ingestive skill abilities.

Keywords::

• Construct validity
• Denmark
• dysphagia
• frailty
• McGill Ingestive Skills Assessment
• occupational therapy

Acknowledgements

We are grateful to all the participating patients and the facilities’ staff, and we thanks occupational therapist Charlotte Ehlers Hansen for throughout assistance in the data collection.

Declaration of interest: The study was financial supported by the Research council at Herlev University Hospital, the Research Foundation of the Danish Occupational Therapy Association (FF2/09-1) and the Lundbeck Foundation (FP03/2011). The authors alone are responsible for the content and writing of the paper. No party supporting this article has or will confer a benefit on us or on any organization with which we are associated.