The Functional Dexterity Test: test-retest reliability analysis and up-to date reference norms.

STUDY DESIGN: Clinical measurement. INTRODUCTION: Among the available tests for fine finger dexterity, the Functional Dexterity Test (FDT) has been indicated as a valid instrument to measure outcome in different conditions. PURPOSE OF THE STUDY: To analyze test-retest reliability, to study the influence of gender, age and hand dominance on the FDT score, and to collect reference norms for adult and elderly age-groups. METHODS: Test-retest reliability was calculated with the Intraclass Correlation Coefficient (ICC) and Standard Error of Measurement (SEM) in a subgroup of 324 healthy volunteers. An enlarged sample of 698 subjects, tested at least once, was used to present stratified data for age group, sex, and hand dominance, and ANOVA was used to investigate statistically significant differences between groups. RESULTS: The FDT showed excellent reliability (ICC > 0.90; SEM: <2 s for net times; <3 s for total scores). Age, gender and hand dominance significantly influenced FDT scores (p < 0.05), but no interaction between variables was found. CONCLUSIONS: FDT is confirmed as reliable, and up-to-date reference norms over a broad range of ages of the Italian adult population have been provided. LEVEL OF EVIDENCE: NA.