The Modified Rankin Scale Can Accurately Be Derived From the Electronic Medical Record

Abstract

INTRODUCTION: The modified Rankin Scale (mRS) is used to assess functional outcomes after a stroke and is the primary outcome in many stroke trials. For retrospective stroke research or stroke research in which patients are lost to study follow up, review of the electronic medical record (EMR) may be the sole way to estimate a patient’s functional outcome. The purpose of this study is to determine if a mRS can be accurately derived from the electronic medical record EMR. METHODS: This study used data from completed stroke studies in which in-person 90-day mRS were collected as part of the study protocol. These scores served as the reference standard. The EMR was searched to find a clinician note from the corresponding time as the 90-day post stroke assessment. These notes were given to three reviewers (an undergraduate research assistant, a medical student, and a neurology resident) to determine a mRS. Their scores were then compared to the inperson assessment and a kappa statistic was calculated. RESULTS: 98 records were reviewed of which 60 met inclusion criteria. Comparing against the in-person mRS: the resident had a weighted kappa (kw) of 0.72, the medical student 0.71, and the research assistant 0.43. Aggregating the mRS into good outcome (mRS 0-2) vs poor outcome (mRS 3-5): the resident had a kw of 0.71, the medical student 0.78, and the research assistant 0.48. DISCUSSION: This study demonstrates that both an absolute mRS and dichotomized mRS can be extracted from the EMR with good agreement by a medical student and neurology resident, but not by a research coordinator (with no formal medical education). Retrospective determination of a dichotomized mRS may be slightly more accurate than an absolute mRS. Researchers may use the EMR to estimate functional outcomes after stroke when in person assessment is not available