THE CLINICAL MEANING OF RANKIN HANDICAP GRADES AFTER STROKE

Background and Purpose The Rankin Scale is a frequently used handicap index in stroke outcome research. However, relatively little is known about its validity. The purpose of this study was to investigate the c linical meaning of Rankin grades by identifying the functional health aspects that contribute to Rankin scores. Methods We studied 438 patie nts 6 months after stroke. Data were collected on the following functi onal health indicators: alertness, communication, independence, disabi lity in activities of daily living, mobility, instrumental disability, social interaction, and recreation. Disability in activities of daily living was assessed with the Barthel Index, whereas the other indicat ors were measured with subscales of the Sickness Impact Profile. The a ssociation between functional health and Rankin Scale was expressed in terms of relative frequencies and Somers' D statistic. Linear regress ion analysis (after ordinal transformation) was used to identify the s ignificant health factors that explain Rankin scores. Results Mobility , disability in daily and instrumental activities, and living arrangem ents showed a stronger association with Rankin scores (Somers' D range , 0.60 to 0.74) than cognitive and social functioning (Somers' D range , 0.34 to 0.47). Disability in activities of daily living turned out t o be the most important explanatory factor of Rankin scores (R(2)=67%) . Conclusions The Rankin Scale is not a pure handicap measure but shou ld be viewed as a global functional health index with a strong accent on physical disability. The index is useful as a simple and time-effic ient outcome measure in large-scale multicenter trials. It is argued t hat at present there is no clear need to assess handicap as the primar y outcome in medically oriented stroke intervention studies.