Prediction of Functional Outcome After Stroke

Comparison of the Orpington Prognostic Scale and the NIH Stroke Scale

Lai, Sue-Min PhD, MS, MBA
Duncan, Pamela W. PhD, PT
Keighley, John MS

Received April 2, 1998; final revision received May 29, 1998; accepted June 10, 1998.
From the Department of Preventive Medicine (S.-M.L., J.K.), and the Center on Aging (P.W.D.), University of Kansas Medical Center, Kansas City; the Department of Veteran Affairs Medical Center (P.W.D.), Kansas City, Mo; and the Department of Health Services Research, University of Kansas, Lawrence.
Correspondence to Sue-Min Lai, PhD, MS, MBA, Department of Preventive Medicine, University of Kansas Medical Center, 3901 Rainbow Blvd, Kansas City, KS 66160-7313. E-mail [email protected].

Stroke 29(9):p 1838-1842, September 1998.

Background and Purpose

This study compared the ability of 2 stroke impairment scales, Orpington Prognostic Scale and National Institutes of Health (NIH) Stroke Scale, to predict disability as measured by the Barthel activities of daily living (ADL) Index and higher level of self-reported physical functioning as measured by the SF-36 physical functioning index (PFI) at 1, 3, and 6 months after stroke.

Methods

The participants in this ongoing study are 184 individuals who sustained an eligible stroke and were recruited for the Kansas City Stroke Study. All patients were prospectively evaluated using standardized assessments at enrollment (within 14 days of stroke onset) and followed at 1, 3, and 6 months after stroke. Coefficient of determination (R²) was used to assess the ability of the 2 stroke scales to prognosticate outcomes.

Results

Means and SDs of the Orpington Prognostic Scale and NIH Stroke Scale measured at baseline were 3.6 +/- 1.31 and 5.5 +/- 4.58, respectively. The Spearman's rank correlation between the 2 baseline measures was 0.83 (P=0.0001). The Orpington Prognostic Scale and the NIH Stroke Scale explained well the variance in Barthel ADL Index (P<0.001). However, the Orpington Prognostic Scale explained more variance than did the NIH Stroke Scale. Similarly, the Orpington Prognostic Score explained more variance in higher level of physical function than did the NIH Stroke Scale. The amount of variance in Barthel ADL Index and SF-36 PFI, which were explained by both stroke severity measures, decreased over time.

Conclusions

Our results demonstrate that in a sample of mostly mild and moderate strokes, the Orpington Prognostic Scale compared with the NIH Stroke Scale is simpler to use and is a slightly better predictor of ADL and higher levels of physical function. (Stroke. 1998;29:1838-1842.)