Does Multiple Neuroimaging Studies Affect Outcome in Acute Ischemic Stroke?

Clinical Question

See title above.

Bottom Line

  1. Multiple CT or MRI scans does not affect who goes home, goes to a skilled nursing facility, or dies after acute ischemic stroke.

See comments below

The Evidence

Outcome One Study Two or more studies p-value
Went home 70.1% 73.3% > 0.1
Went to SNF or required daily home care 24.0% 24.4% > 0.1
Died 5.9% 2.2% >0.1
  1. Patients who had one study were compared to patients who had more than one study retrospectively, and important determinants of stroke were compared. No statistically significant differences were found between the two groups, and each group did not differ significantly from the total number of patient characteristics.
  2. Two or more imaging studies resulted in a reclassification of stroke type in 20% (According to TOAST criteria, described elsewhere). Multiple imaging studies increased the certainty factor in 1/3 of the patients classified with stroke. No patients were reclassified as no stroke after multiple studies.
  3. Duration of hospital stay was not statistically significant in the two groups.

Comments

  1. This was a well-intended study. However, there are several flaws present which impact on its conclusions and applicability.
  2. This was a retrospective case-series, and no analyses were done to adjust for other important determinants of OUTCOME, which were not addressed in this paper.
  3. No analysis was done to measure accuracy and reproducibilty of prognostic factors, which was not part of the study methods.


This study was a fair attempt to show that multiple neuroimaging studies did not significantly affect hospital length of stay, whether patients went home or went to a SNF, or died. However, there is insufficient statistical power to show that other potential important prognostic factors were or were not responsible for the observed outcomes.

APPRAISED BY: Patrick Sousa, MD

DATE: April 16, 1996

Salerno SN, et al. The Effect of Multiple Neuroimaging Studies on Classification, Treatment, and Outcome of Acute Ischemic Stroke. Ann Intern ed 1996;124:21-26.