Applying measurement theories to the advancement of the Chedoke Arm and Hand Activity Inventory

Abstract

Background: The use of outcome measures to evaluate upper extremity function after stroke is highly recommended in clinical practice and research. The Chedoke Arm and Hand Activity Inventory (CAHAI) is a recommended measure as it has strong psychometric properties and clinical utility. However, the measure has not been validated in Asia and there are also gaps in the knowledge about the psychometric properties of the CAHAI. Aim & Objectives: This thesis is dedicated to the continued evaluation of the CAHAI with two main objectives: (1) to develop a Singapore version of the CAHAI, and (2) to re-evaluate the original CAHAI using modern test theories. Method: We conducted a study to cross-culturally adapt the CAHAI and evaluated the psychometric properties in a stroke sample in Singapore. Two studies were conducted to re-evaluate the original CAHAI using modern test theories. In the first study, item response theory and Rasch measurement theory were used to evaluate the psychometric properties of the measure. Following which, both measurement theories were used to revise the CAHAI in the second study. Results: Two test items were modified for the Singapore version of the CAHAI, and the measure had good inter-rater reliability (intra-class correlation coefficient = 0.95 – 0.97) and construct validity. The evaluation of the original CAHAI using modern test theories identified three main problems: (1) the scoring scale was not working as intended, (2) local dependency, and (3) the measure was not unidimensional. Revisions to the CAHAI included collapsing the 7-category scale to four categories, deleting two test items, and developing two new shortened versions. Conclusion: The Singapore version of the CAHAI is a valid and culturally relevant outcome measure that can be used to evaluate post-stroke upper extremity function. The original CAHAI was refined into a new 11- and 5-item versions with a 4-category scale which clinicians may find easier to use.