Disability status at 1 month is a reliable proxy for final ischemic stroke outcome

Area of Science:

• Neurology
• Clinical Trials
• Health Services Research

Background:

• The standard 3-month assessment for functional status after acute ischemic stroke is lengthy.
• Earlier outcome assessment is needed for stroke quality improvement and clinical trials to reduce patient dropout.

Purpose of the Study:

• To determine if day 30 global disability status reliably predicts final 3-month disability outcomes in acute stroke patients.
• To evaluate the utility of early outcome measures in stroke research and care.

Main Methods:

• Analysis of 5,997 acute stroke patients from the Virtual International Stroke Trials Archive dataset.
• Partitioning data into derivation (n=4,051) and validation (n=1,946) cohorts.
• Assessing global disability using the modified Rankin Scale (mRS) at day 30 and day 90, with statistical analysis including weighted kappa and multivariable logistic modeling.

Main Results:

• A strong correlation (r=0.87, p<0.001) and high agreement (weighted kappa=0.86) were found between day 30 and day 90 mRS scores.
• Day 30 mRS was the dominant predictor of day 90 mRS, explaining 65.6% of the variance.
• Other baseline variables collectively explained only a minor additional 1.8% of the outcome variance.

Conclusions:

• Global disability status at 1 month post-ischemic stroke is a reliable predictor of 3-month outcomes.
• One-month disability assessment can be a dependable and efficient outcome measure for stroke quality improvement initiatives and specific clinical trials.