Development of the Variable Dexterity Test: construction, reliability and validity

Background/Aims: This article introduces a dexterity test designed to assess individual types of dexterity used to carry out activities of daily living (ADL). The Variable Dexterity Test (VDT) was developed as part of a wider study, the broader aim being to fully understand dexterity and its effect on human-product interaction during ADL. This was done with a view to improve occupational therapy methods when assessing dexterity and general hand function.

Methods: The control group consisted of 24 healthy participants. Estimates of reliability and validity were evaluated in this pilot study. Inter-rater and test-retest reliability were assessed using a one-way ANOVA. The validity of the test was estimated by correlating participants’ VDT scores with their proficiency to complete four ADL task actions and a standardised dexterity test (Purdue Pegboard Test).

Results: The test produced consistent results among the control group with both a single assessor (test‑retest reliability) and multiple assessors (inter‑rater reliability). High correlations between participants’ VDT scores and proficiency to perform ADL were found for most of the subtests. There was also a high correlation between participants’ scores from the Purdue Pegboard Test and the VDT.

Conclusions: The VDT proved to be a flexible, reliable and valid tool that assesses dexterity based on ability to carry out ADL. Validity and reliability estimates show encouraging values, which recognises that the VDT can be used as an accurate method to assess more than one type of dexterity.