Abstract TP175: Influence of Social Role Differences Between Age Groups and Between the Sexes Upon Modified Rankin Scale Global Disability Scores

Background: The modified Rankin Scale (mRS) aligns with the World Health Organization’s disability definition by having scores determined by: 1) impairments (neurologic deficits), 2) functional limitations (difficulties in performing activities), and 3) social role restrictions (reduced work, family/relationship, recreational/leisure responsibilities). Social role restrictions are particularly important in assigning patients between mRS 1 (“able to perform all work, family, and social roles”) vs mRS 2 (“unable to perform all work, family, and social roles, but able to live independently”). Since social role disparities exist in modern societies, mRS scores could vary between age groups and between sexes for cultural rather than clinical reasons. Methods: We studied patients with a final diagnosis of acute ischemic or hemorrhagic stroke in the NIH FAST-MAG phase 3 trial, a multicenter, placebo-controlled, randomized trial of prehospital- initiated magnesium sulfate in stroke patients within 2h of onset. Patients were stratified by sex and 4 age groups to distinguish working- and retirement-age populations: 1) <60y; 2) <65y; 3) ≥65y; and 4) >70y. We calculated the 3m mRS 1 vs 2 distributions for each age group and for men and women. Results: Among 1622 final diagnosis stroke patients, 57.8% were men, 42.2% women. At 3 months, 615 (31.8%) of patients had an mRS score of 1 or 2. Age was strongly associated with greater likelihood of an mRS 2 than mRS 1 score. Among patients <65 years, the rate of mRS 2 outcomes among all patients with an mRS 2 or mRS 1 score was 65.8%; among patients age ≥65, the rate of mRS 2 outcomes among all patients with mRS 2 or mRS 1 was 33.3%. A sex-age interaction was also noted (Figures 1, 2). Below age 60, men were more likely than women to receive an mRS score of 2 rather than 1. But as age increased, women were increasingly more likely than men to receive an mRS score of 2 rather than 1. Conclusions: Global disability scores on the modified Rankin Scale exhibit age-based and sex-based disparities. Individuals of retirement age are more likely to be scored as nondisabled compared with working age persons. Further, in the retirement age group but not earlier, men are more likely to be scored as nondisabled compared with women. This influence of culturally determined life roles upon scale scores should be incorporated into interpretation of clinical trial mRS outcome distributions.