Abstract T P275: Quantification of Potential Bias in Databases That Require Consent in Acute Stroke
Background: The stroke database at our institution includes patients who gave consent and are followed up at 90 days after acute stroke and a group entered into our registry in whom only limited data is available under a consent waiver. We explore the potential bias that is introduced by the requirement to obtain consent.
Methods: We included patients with an admission diagnosis of acute ischemic stroke. For each of the groups (database versus registry), we analyzed age, sex, race/ethnicity, hypertension, diabetes, history of atrial fibrillation, smoking status, pre-stroke mRS, baseline NIHSS, presence of aphasia, and use of IV rt-PA. We used Wilcoxon Rank-sum test for continuous and Fisher's Exact for categorical variables.
Results: A total of 1800 patients were included (database 849, registry 951). In the database versus registry 84.6% were white versus 79.9% (p=0.006); baseline NIHSS was 8.6±8.1 versus 10.6±9.2; aphasia 38.6% versus 44% (p=0.03); pre-stroke disability (mRS >1) 21.5% versus 30% (p<0.0001) and IV rt-PA use 47.7% versus 26.5% (p<0.0001). There was no difference in age, sex, smoking status, the frequency of diabetes, atrial fibrillation, hypertension and ethnicity (Hispanic) between the groups.
Conclusion: In our comparison between a database requiring consent and a registry utilizing consent waiver, we found that the database included more whites, patients with lower NIHSS, fewer patients with aphasia and pre-stroke disability. Requiring consent in acute stroke may introduce bias against minorities and patients with more severe stroke and/or aphasia. Future projects should take this into consideration and focus on reducing bias.
Author Disclosures: H. Ramani: None. R. Raman: None. K. Ernstrom: None. M.N. Ali: None. D.M. Meyer: Speakers' Bureau; Modest; Chiesi. R. Modir: None. K.S. Rapp: None. B.C. Meyer: Speakers' Bureau; Modest; Genentech. T.M. Hemmen: Consultant/Advisory Board; Modest; Merck.
- © 2015 by American Heart Association, Inc.