Distal symmetric polyneuropathy: A definition for clinical research

Figure. The diagnostic accuracy levels of symptoms, signs, or combinations of symptoms or signs (predictors) for the presence of distal symmetric polyneuropathy are indicated in graphic format. Predictors are plotted according to their sensitivity and specificity. Points plotted near the top of the graph correspond to predictors with high sensitivity for distal symmetric polyneuropathy. Points plotted near the left side of the graph correspond to predictors with high specificity. Thus, points nearest the upper left hand corner correspond to predictors with the highest diagnostic accuracy (both high sensitivity and specificity) for distal symmetric polyneuropathy. Points falling near the diagonal line correspond to predictors with low diagnostic accuracy. Vertical diamonds represent the diagnostic accuracy of symptoms, triangles signs, shaded + or x quantitative sensory tests. Points describing the diagnostic accuracy of a single symptom (e.g., numbness) or a single examination finding (e.g., absent ankle reflexes) are enclosed by dashed circles and ovals. Points describing the diagnostic accuracy of more than one symptom (e.g., numbness or pain) or more than one sign (e.g., absent ankle reflexes or decreased distal sensation) are not enclosed in dashed circles and ovals. The number just to the upper right of a plotted point references the study from which the sensitivity and specificity of that predictor was obtained.