How much change in the stroke impact scale-16 is important to people who have experienced a stroke?
BACKGROUND
The Stroke Impact Scale-16 (SIS-16) is used clinically and in research to measure quality of life after stroke. There are no studies that have estimated how much change on the SIS-16 is an important amount of change. The aim of this study was to estimate the minimal clinically important difference (MCID) of the SIS-16.


METHODS
SIS-16 scores of participants receiving services at 2 outpatient physical therapy clinics who met inclusion and exclusion criteria (n = 36) were taken at baseline and discharge. At discharge, participants and their physical therapists rated their perceived amount of recovery on a Global Rating of Change (GROC) scale. Estimated MCID values were calculated for the SIS-16 using receiver operating characteristics curves with the GROC as anchors.


RESULTS
There was no difference in baseline characteristics between participants who reported important improvement and those who did not. There was a fair relationship between change in SIS-16 scores and participants' (0.41) and physical therapists' (0.38) GROC scores. Change in SIS-16 scores was significantly greater in participants who reported an important amount of change on the GROC scale and those who did not. Estimated MCID of the SIS-16 ranged from 9.4 to 14.1 depending on the anchor.


CONCLUSIONS
The estimated MCID values presented in this study provide a way for clinicians to evaluate meaningful change in individual patients and for researchers to evaluate meaningful change between groups.
Physical Therapy Department, Clarkson University, Potsdam, NY, USA.
George D
GD
Fulk
Miriam
M
Ludwig
Kari
K
Dunning
Sue
S
Golden
Pierce
P
Boyne
Trent
T
West
D000203:Activities of Daily Living; D019540:Area Under Curve; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D026741:Physical Therapy Modalities; D011788:Quality of Life; D012372:ROC Curve; D020127:Recovery of Function / Q000502:physiology*; D012720:Severity of Illness Index; D020521:Stroke / Q000503:physiopathology* / Q000523:psychology*; D000071939:Stroke Rehabilitation; D013997:Time Factors; D016896:Treatment Outcome