Comparison of telephone and face-to-face assessment of the modified Rankin Scale.
BACKGROUND
A structured interview improves the reliability of the modified Rankin Scale (mRS), a commonly used functional outcome scale in stroke trials. Telephone interview is a fast and convenient way to assess the mRS grade, but its validity is unknown. We assessed the validity of a telephone interview in patients who had had an aneurysmal subarachnoid haemorrhage (SAH) by comparing it with a face-to-face assessment.


METHODS
Eighty-three SAH patients were interviewed twice, once face-to-face and once by telephone, by 2 of 5 observers who used a structured interview to assess the mRS grade. Intermodality agreement was measured using weighted kappa statistics. To check for systematic differences between face-to-face and telephone assessment the Wilcoxon test for matched pairs was used.


RESULTS
Agreement between telephone and face-to-face assessment was perfect in 47 (57%) patients. A difference of 1 level occurred in 31 (37%) patients and this was almost equally distributed over the grades of the mRS. Weighted kappa was 0.71 (95% CI 0.59-0.82). Telephone assessment did not result in a consistently more or less favourable grade than face-to-face assessment (Wilcoxon test for matched pairs, p = 0.33).


CONCLUSIONS
Telephone assessment of the mRS with a structured interview has a good agreement with face-to-face assessment and can thus be used reliably in the setting of a clinical trial.
Janssen
Paula M
PM
Department of Neurology, University Medical Centre Utrecht, Utrecht, The Netherlands.
Visser
Nora A
NA
Dorhout Mees
Sanne M
SM
Klijn
Catharina J M
CJ
Algra
Ale
A
Rinkel
Gabriel J E
GJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D020127:Recovery of Function; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013345:Subarachnoid Hemorrhage / Q000175:diagnosis* / Q000503:physiopathology / Q000628:therapy*; D013689:Telephone; D016896:Treatment Outcome