Validation of the Simplified Modified Rankin Scale Questionnaire

INTRODUCTION The modified Rankin scale (mRS) is the most common assessment tool for measuring overall functional outcome in stroke studies. The traditional way of using mRS face-to-face is time- and cost-consuming. The aim of this study was to test the validity of the Swedish translation of the simplified modified Rankin scale questionnaire (smRSq) as compared with the mRS assessed face-to-face 6 months after a stroke. METHODS Within the ongoing EFFECTS trial, smRSq was sent out to 108 consecutive stroke patients 6 months after a stroke. The majority, 90% (97/108), of the patients answered the questionnaire; for the remaining 10%, it was answered by the next of kin. The patients were assessed by face-to-face mRS by 7 certified healthcare professionals at 4 Swedish stroke centres. The primary outcome was assessed by Cohen's kappa and weighted kappa. RESULTS There was good agreement between postal smRSq, answered by the patients, and the mRS face-to-face; Cohen's kappa was 0.43 (CI 95% 0.31-0.55), weighted kappa was 0.64 (CI 95% 0.55-0.73), and Spearman rank correlation was 0.82 (p < 0.0001). In 55% (59/108), there was full agreement, and of the 49 patients not showing exact agreement, 44 patients differed by 1 grade and 5 patients had a difference of 2 grades. DISCUSSION/CONCLUSION Our results show good validity of the postal smRSq, answered by the patients, compared with the mRS carried out face-to-face at 6 months after a stroke. This result could help trialists in the future simplify study design and make multicentre trials and quality registers with a large number of patients more feasible and time-saving.