Validation of a manual ability questionnaire in patients with systemic sclerosis

Abstract

Objective. To adapt and validate a manual ability questionnaire, the ABILHAND, developed through the Rasch methodology in patients with systemic sclerosis (SSc). Methods. The original version of the ABILHAND, which includes 81 manual daily activities, was presented to 156 patients with SSc. They were asked to provide their perceived difficulty in performing each manual activity on a 3-level scale: impossible, difficult, or easy. Items were selected from well-established psychometric criteria. The patients were reassessed 1 month later to test the reproducibility. Concomitantly, they were clinically evaluated for their disease activity/severity, and their functional ability was tested with the Health Assessment Questionnaire (HAQ). Results. The 26 selected items defined a unidimensional and linear measure of manual ability and showed a continuous progression in their difficulty. The item difficulty hierarchy was invariant across 12 patient-related factors and the manual ability score was reproducible over time. Finally, the manual ability was significantly poorer in SSc patients with more severe disease, and was negatively correlated with the HAQ score ( ‫؍‬ ؊0.733). Conclusion. The SSc-adapted ABILHAND questionnaire is a reliable, valid, reproducible, linear, and unidimensional measure to assess and followup on the manual ability of patients with SSc; therefore, it could become a useful additional tool in clinical trials to assess treatment efficacy.

Can manual ability be measured with a generic ABILHAND scale? A cross-sectional study conducted on six diagnostic groups

“…For each diagnosis, the scale content was selected to delineate a single unidimensional construct, correlated to the patients' functional, clinical and demographic characteristics. [6][7][8][9][10] The nature of the measured variable, namely, manual ability, can be determined by investigating the factors contributing to the hierarchy of manual item difficulty, that is, observed across diagnoses. To address this issue, we developed an original methodology that combines DIF tests, PCA and manual activities categorisation about their nature.…”

“…In contrast, digital activities (eg, 'winding up a wristwatch') were particularly difficult for SSc subjects, who have reduced digital dexterity. 9 Other characteristics of the diseases than their symmetric/asymmetric or proximal/digital nature may explain, even though to a lesser extent, the variations of item difficulty hierarchy between disorders. Activities inducing high mechanical constraints on the upper limb joints (eg, 'screwing on a nut') presented the highest challenge for RA patients owing to wrist and metacarpophalangeal joint involvement.…”

“…Patients with the following disorders were evaluated: 103 CS adults, 6 113 CP children, 7 112 RA adults, 8 156 SSc adults, 9 124 NMD children (NMDc) and 124 NMD adults (NMDa). 10 Table 1 provides patient characteristics.…”

“…ABILHAND scales are self-administered questionnaires that measure 'manual ability', which is defined as, 'the capacity to manage daily activities requiring the use of the upper limbs, whatever the strategies involved'. 6 Disease-specific manual ability 'rulers' were previously developed for the following patient groups: chronic stroke (CS), 6 cerebral palsy (CP), 7 rheumatoid arthritis (RA), 8 systemic sclerosis (SSc) 9 and neuromuscular disorders (NMD). 10 Each ABILHAND scale has its own Rasch-derived item difficulty calibration, which defines a disease-specific manual ability measurement continuum.…”

Validation of the ABILHAND questionnaire to measure manual ability in children and adults with neuromuscular disorders

“…Manual ability, defined as the capacity to use the hands and upper limbs to perform manual daily activities regardless of the strategies involved,8 can be assessed with the ABILHAND questionnaire. This questionnaire was previously validated in patients with chronic stroke,9 children with cerebral palsy,10 patients with rheumatoid arthritis11 and patients with systemic sclerosis 12. ABILHAND is a self-reported, widely applicable questionnaire.…”