Background and purpose: The purpose of the study is to compare the reliability of the Barthel activities of daily living score, which assesses disability, with the Rankin scale, which assesses handicap, and to determine their mutual agreement.
Methods: Fifty patients with stroke of varying severity were identified by a community-based stroke register and interviewed by two of three research nurses on two occasions that were 2-3 weeks apart.
Results: There was no evidence of a systematic difference between the first and second measurements. Repeatability was assessed using a kappa statistic with quadratic disagreement weights (kappa w) to take account of extreme differences. This measure was very good for both Barthel (kappa w = 0.98) and Rankin (kappa w = 0.95) scales. There was also excellent agreement between raters for the Barthel scale (kappa w greater than or equal to 0.88), but some indication of disagreement (kappa w = 0.75) between raters for the Rankin scale. Analysis of variance confirmed these findings. A conversion from the Barthel to the Rankin scale can be derived by assigning the most common Rankin score for the subjects with a given Barthel score, producing a kappa w of 0.91 for agreement.
Conclusions: The Barthel scale is a more reliable and less subjective scale for assessing disability, from which a Rankin handicap score can then be derived to enable those managing stroke patients to assess aspects of handicap as well as disability.