Outcome after stroke attributable to baseline factors—The PROSpective Cohort with Incident Stroke (PROSCIS)

Abstract

BackgroundThe impact of risk factors on poor outcome after ischemic stroke is well known, but estimating the amount of poor outcome attributable to single factors is challenging in presence of multimorbidity. We aim to compare population attributable risk estimates obtained from different statistical approaches regarding their consistency. We use a real-life data set from the PROSCIS study to identify predictors for mortality and functional impairment one year after first-ever ischemic stroke and quantify their contribution to poor outcome using population attributable risks.MethodsThe PROSpective Cohort with Incident Stroke (PROSCIS) is a prospective observational hospital-based cohort study of patients after first-ever stroke conducted independently in Berlin (PROSCIS-B) and Munich (PROSCIS-M). The association of baseline factors with poor outcome one year after stroke in PROSCIS-B was analysed using multiple logistic regression analysis and population attributable risks were calculated, which were estimated using sequential population attributable risk based on a multiple generalized additive regression model, doubly robust estimation, as well as using average sequential population attributable risk. Findings were reproduced in an independent validation sample from PROSCIS-M.ResultsOut of 507 patients with available outcome information after 12 months in PROSCIS-B, 20.5% suffered from poor outcome. Factors associated with poor outcome were age, pre-stroke physical disability, stroke severity (NIHSS), education, and diabetes mellitus. The order of risk factors ranked by magnitudes of population attributable risk was almost similar for all methods, but population attributable risk estimates varied markedly between the methods. In PROSCIS-M, incidence of poor outcome and distribution of baseline parameters were comparable. The multiple logistic regression model could be reproduced for all predictors, except pre-stroke physical disability. Similar to PROSCIS-B, the order of risk factors ranked by magnitudes of population attributable risk was almost similar for all methods, but magnitudes of population attributable risk differed markedly between the methods.ConclusionsRanking of risk factors by population impact is not affected by the different statistical approaches. Thus, for a rational decision on which risk factor to target in disease interventions, population attributable risk is a supportive tool. However, population attributable risk estimates are difficult to interpret and are not comparable when they origin from studies applying different methodology. The predictors for poor outcome identified in PROSCIS-B have a relevant impact on mortality and functional impairment one year after first-ever ischemic stroke.

Trends in ischemic stroke outcomes in a rural population in the United States

“…Epidemiologic data regarding stroke recurrence among younger patients are limited. In addition, several factors including older age [44], hypertension [45], diabetes [46,47], and current smoking [45] are associated with stroke death. Appelros et al showed that old age, atrial fibrillation, stroke severity, and dementia were predictors of poor outcomes including death within one-year after stroke [48].…”

Predictors of stroke subtype and severity in patients of a tertiary care hospital, Dehradun

“…[ 17 ] Low education is related to poor stroke outcome also. [ 18 ]…”

Cognitive Reserve as an Emerging Concept in Stroke Recovery

“…Dementia occurs in approximately 10% and 34.4% of first-ever mild and severe stroke survivors, respectively, within the first year poststroke, and in around 30% of stroke survivors after recurrent stroke. 39,70,71 In fact, evidence suggests that those with higher cognitive reserve (higher educational attainment) are at a decreased risk of developing dementia following stroke and/or transient ischemic attack (see Mirza et al 71 and Malsch et al 72 ). It should also be mentioned that brain reserve might also be a suitable target for intervention.…”