https://immattersacp.org/weekly/archives/2011/02/08/7.htm

Prognostic scores don't reliably predict early recurrence after minor stroke

Leading prognostic scores don't reliably predict risk for early recurrence after a minor stroke, a new study has indicated.


Leading prognostic scores don't reliably predict risk for early recurrence after a minor stroke, a new study has indicated.

Researchers used data from the Oxford Vascular Study, a prospective, population-based study of all incident and recurrent stroke in Oxfordshire, United Kingdom, to examine the prognostic value of three stroke scores for early recurrence after minor stroke: the ABCD2 score, the Essen Stroke Risk Score and the Stroke Prognosis Instrument II. Strokes were considered minor if they scored 5 or lower on the National Institutes of Health Stroke Scale. The study was published online Jan. 27 by Stroke.

A total of 1,247 first events occurred from April 1, 2002 to March 31, 2007. Of these, 488 were transient ischemic attacks, 520 were minor strokes and 239 were major strokes. Patients were a mean age of 73 years (range, 24 to 98 years) when the first event occurred. One hundred forty-two recurrent strokes occurred within 90 days of the first event, 81 within 7 days and 111 within 30 days. Only the ABCD2 score was predictive of recurrence 7 and 90 days after minor stroke, and its predictive value was modest (area under the receiver operator curve, 0.64, 95% CI, 0.53 to 0.74, P=0.03 and 0.62, 95% CI, 0.54 to 0.70, P=0.004, respectively). The Essen Stroke Risk Score and the Stroke Prognosis Instrument II did not predict 7-day or 90-day risk. The authors examined the risk factors included in the ABCD2 score and found that only two, blood pressure above 140/90 mm Hg at first evaluation and large artery disease, predicted 90-day recurrence risk (hazard ratio, 2.75, 95% CI, 1.18 to 6.38, P=0.02 and 2.21, 95% CI, 1.00 to 4.88, P=0.05, respectively).

The authors noted that their estimates of stroke risk may have been imprecise because some patients with minor stroke don't seek medical care, and that relatively few outcomes were used to validate the scores for recurrence. However, they concluded that these three existing scores do not adequately predict early risk for recurrence after minor stroke. “More reliable early risk prediction after minor stroke is required,” they wrote.