Test-retest reliability of the ABILHAND questionnaire in persons with chronic stroke.

BACKGROUND Reliable and valid outcome measures are needed to be able to evaluate recovery, effects of rehabilitation interventions, and changes over time. The ABILHAND Questionnaire is a measure of a patient's self-reported ability to perform complex daily activities involving use of the hand. This instrument is commonly used in stroke rehabilitation settings, but data about the measurement variability are missing. OBJECTIVE To assess the test-retest reliability of the ABILHAND Questionnaire in persons with chronic stroke and to define limits for the smallest change that indicates a real change, both for a group of individuals and for a single individual. DESIGN A test-retest reliability study. SETTINGS University hospital. PARTICIPANTS A convenience sample of 43 persons (11 women and 32 men; mean age 64 years) with mild to moderate impairments of hand function 6-48 months after sustaining a stroke. INTERVENTION Not applicable. MAIN OUTCOME MEASUREMENTS The ABILHAND Questionnaire is Rasch analyzed, enabling ordinal data to be converted into an interval scale (logits) and the use of parametric statistical analyses. The participants responded to 23 items in the ABILHAND Questionnaire on 2 occasions, 2 weeks apart. Reliability was assessed with the intraclass correlation coefficient (ICC22.1), the mean difference between the test sessions (đ) together with the 95% confidence intervals for đ, the standard error of measurement (SEM and SEM%), the smallest real difference (SRD and SRD%), and a Bland and Altman graph. RESULTS Four outliers with high mean logit scores (>4.0) were identified in the sample. The results therefore are presented both for the entire sample (n = 43) and without the 4 outliers (n = 39). The test-retest agreement was high: ICC2,1 = 0.85 (n = 43) and 0.91 (n = 39). The SEM%, which represents the smallest change that indicates a real improvement for a group of individuals, was 21% (n = 43) and 15% (n = 39). The SRD%, which represents the smallest change that indicates a real clinical improvement for a single individual, was 59% (n = 43) and 42% (n = 39), respectively. CONCLUSION The ABILHAND Questionnaire is reliable in persons with chronic stroke and can be recommended to evaluate recovery, rehabilitation interventions, and changes over time in a group of individuals but is less suitable for a single individual.