Department of Family Medicine
Stroke Impact Scale
P.W. Duncan, D. Wallace, S.M. Lai, D. Johnson, S. Embretson, L.J. Laster (1999)
Background and Development:
The SIS was designed to be useful in clinical research as an outcome measure which is easy to administer and has sound psychometric attributes. This 64-item questionnaire is self-administered, with each item scored on a 5-point Likert scale, and assesses 8 domains of stroke (Strength, Hand Function, Activities of Daily Living / Instrumental Activities of Daily Living, Mobility, Communication, Emotion, Memory and Thinking, and Participation).Factor analysis revealed that the first four domains can be combined into a single Overall Physical domain. The other four domains represent distinct dimensions of recovery. The SIS also includes a visual analog scale where the patient estimates his percent recovery from his stroke. The SIS is available in a proxy version for when patients are unable to answer for themselves.
Reliabilities of the eight domains are very good (Cronbach alpha 0.83 to 0.90). Validity was measured by comparison of mean scores to Rankin levels. Six of the eight domains showed significant differences (p<0.05) across the Rankin levels. SIS domain scores show good correlations with a variety of other measures, including the SF-36, NIHSS, and Barthel Index. Three domains (Overall Physical, Emotion, and Participation) were predictors of self-assessed recovery. The SIS is sensitive to change in most domains from 1-3 and 1-6 months for patients with mild to moderate strokes.
More information about the SIS and an updated SIS Version 3.0 with 59 items can be found at the University of Kansas Medical Center, Center on Aging Website: www2.kumc.edu/coa
Validation in Elderly Populations:
Average age of the initial population was 71.
Validation in Minority Populations:
The SIS has not been tested specifically in minority populations, however, the instrument has been translated into 14 other languages and used around the world.
Lai et al. (2002) determined that the SIS can still measure long-term (90-day) effects from stroke even when the Barthel Index has determined that the patients are fully recovered.
Design Strengths and Weaknesses:
The SIS is more discriminative than other indices (such as the Barthel Index) in patients with mild to moderate strokes. There is less of a ceiling effect with fewer patients scoring at or near maximum values. The SIS shows very good reliability and validity in comparison to other measures. It is responsive to changes in patient ability over time making it a good clinical measure.
This SIS questionnaire and scoring algorithm is published as an appendix in Duncan et al. (1999): Hard copy and Access database versions are also available at www2.kumc.edu/coa. The Stroke Impact Scale is a copyrighted instrument. It can be copied and used freely but cannot be changed.
Duncan, P.W., D. Wallace, S.M. Lai, D. Johnson, S. Embretson, L.J. Laster (1999) The Stroke Impact Scale Version 2.0. Evaluation of reliability, validity, and sensitivity to change. Stroke 30, 2131-2140.
Lai, S.M., S. Studenski, P.W. Duncan, and S. Perera (2002) Persisting consequences of stroke measured by the Stroke Impact Scale. Stroke 33(7), 1840-1844.