Determining cut-off points in functional assessment scales in stroke

BACKGROUND: A wide variety of well-validated assessment scales of functioning and disability have been developed for stroke population. However, these instruments have limitations in their interpretation. Therefore, determining cut-off points for their categorization becomes necessary. OBJECTIVES: To determine cut-off points for the BI, FIM and FAM scales to differentiate clinical disability categories and to establish the relationship between mRS and DOS scales. METHODS: One hundred and six adults with ischemic or haemorrhagic stroke were mainly recruited from a rehabilitation facility (Hospitales Nisa, Valencia, Spain). RESULTS: A high correlation was observed between the DOS and mRS scales (Kendall's tau-b = 0.475; p = 0.000) although a certain amount of disagreement between the two scales was detected. The cut-off points were 62.90 (95% CI, 57.26-69.29) and 21.30 (95% CI, 16.34-26.03) for the BI; 70.62 (95% CI, 66.65-75.22) and 38.29 (95% CI, 34.07-42.25) for the FIM; and 116.07 (95% CI, 110.30-122.68) and 66.02 (95% CI, 59.20-72.35) for the FAM. CONCLUSION(S): DOS was observed to be more demanding than the mRS, in terms of patient independence. Additionally, the lower cut-off points separating the levels of severe and moderate disability in the BI, FIM and FAM were determined. These findings would facilitate practitioners clinical interpretation of disability levels in post-stroke patients.