Improving the assessment of outcomes in stroke: use of a structured interview to assign grades on the modified Rankin Scale.
OBJECTIVE
The modified Rankin Scale is widely used to assess changes in activity and lifestyle after stroke, but it has been criticized for its subjectivity. The purpose of the present study was to compare conventional assessment on the modified Rankin Scale with assessment through a structured interview.


METHODS
Sixty-three patients with stroke 6 to 24 months previously were interviewed and graded independently on the modified Rankin Scale by 2 observers. These observers then underwent training in use of a structured interview for the scale that covered 5 areas of everyday function. Eight weeks after the first assessment, the same observers reassessed 58 of these patients using the structured interview.


RESULTS
Interrater reliability was measured with the kappa statistic (weighted with quadratic weights). For the scale applied conventionally, overall agreement between the 2 raters was 57% (kappa(w)=0.78); 1 rater assigned significantly lower grades than the other (P=0.048). On the structured interview, the overall agreement between raters was 78% (kappa(w)=0.93), and there was no overall difference between raters in grades assigned (P=0.17). Rankin grades from the conventional assessment and the structured interview were highly correlated, but there was significantly less disagreement between raters when the structured interview was used (P=0.004).


CONCLUSIONS
Variability and bias between raters in assigning patients to Rankin grades may be reduced by use of a structured interview. Use of a structured interview for the scale could potentially improve the quality of results from clinical studies in stroke.
Wilson
J T Lindsay
JT
Department of Psychology, University of Stirling, Stirling, UK. J.T.L.Wilson@stir.ac.uk
Hareendran
Asha
A
Grant
Marie
M
Baird
Tracey
T
Schulz
Ursula G R
UG
Muir
Keith W
KW
Bone
Ian
I
D000203:Activities of Daily Living / Q000145:classification*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007407:Interviews as Topic / Q000379:methods*; D008019:Life Style; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D017063:Outcome Assessment, Health Care / Q000379:methods*; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D020521:Stroke / Q000175:diagnosis; D000071939:Stroke Rehabilitation