Shortening the Haemophilia Activities List (HAL) from 42 items to 18 items

INTRODUCTION: The Haemophilia Activities List (HAL) was developed to measure activities and participation in persons with haemophilia (PWH). Shortening the questionnaire may facilitate use of the HAL. AIM: The aim of this study was to determine which items of the HAL are redundant, to construct a shorter version of the HAL, and to determine the construct validity of the HAL(short). METHODS: A secondary analysis was performed on pooled data of two published studies using the HAL (seven domains, 42 items, optimum score: 100) in adults with haemophilia A/B. Data were divided into a derivation (62%) and a validation set (38%). Redundant items were identified by evaluation of: floor and ceiling effects, proportions of missing and ‘not applicable’ responses, inter‐item correlations, component loadings in an exploratory factor analysis, internal consistency, and item‐total correlations. Correlations with the SF‐36 and EQ‐5D‐5L were used to determine construct validity of the HAL(short). RESULTS: Data on 680 PWH were evaluated. In the derivation dataset (n = 420), median age was 30 years (range 18–80), 43% had severe haemophilia and 61% received prophylaxis. Median (IQR) HAL sum score was 65.0 (55.7–88.8). The stepwise procedure resulted in a HAL(short) of 18 items with a median sum score of 63.3 (54.4–86.7). Construct validity was similar for the HAL and HAL(short) in the validation dataset (n = 260). CONCLUSION: This clinimetric study resulted in a >50% shortening of the HAL. The 18‐item HAL(short) reduces patient burden and is expected to capture the information on activities and participation. The HAL(short) needs further validation.