Ascribing leg symptoms to chronic venous disorders: The construction of a diagnostic score

Objectives The goal was to create a simple diagnostic scoring system able to differentiate leg symptoms related to chronic venous disorders (CVD) from those produced by other causes. Methods A prospective observational study was done of ambulatory or hospitalized patients from 13 private and five institutional vascular centers. Two groups of patients with leg symptoms were investigated. The CVD-positive (CVD+) patients had clinically documented CVD and significant venous reflux at duplex ultrasound examination, but no arterial, rheumatologic, or neurologic disorders. The CVD-negative (CVD−) patients had disorders of an arterial, rheumatic, or neurologic origin but no clinical or duplex ultrasound signs of CVD. Patients completed a 54-item questionnaire characterizing their symptoms. Items of the diagnostic score were selected as those associated with the highest likelihood ratio (LR) for CVD in a first series of patients. They were combined into a few criteria, the number of which, when validated in a patient, would produce the value of the score for this patient. Selection of the most relevant score was performed through the comparison of the surface area under receiver operating characteristic curves. The construct validity of this score was evaluated through a factor analysis. The diagnostic performance of the scoring system was evaluated in a second series of patients similar to the first series. Results In the construction phase, 123 CVD+ patients and 94 CVD− patients were enrolled. The validation series consisted of 92 patients (67 venous and 25 nonvenous). The most efficient scoring system was composed of four combined criteria: sensation of heavy or swollen legs (sensitivity, 0.82; specificity, 0.55; LR, 1.84); associated with itching, impatient legs, or phlebalgia (sensitivity, 0.55; specificity, 0.92; LR, 6.41); worsened by a hot environment or improved by a cold environment (sensitivity, 0.78; specificity, 0.71; LR, 2.72); not worsened by walking (sensitivity, 0.89; specificity, 0.62; LR, 2.33). The score was calculated as the number (0 to 4) of the above criteria validated by the patient, with a threshold level of >3, it was shown to have a high specificity (0.95) and a fair sensitivity (0.75) for CVD. Factor analysis showed the construct validity of the score, and consistent results were found in the validation series. Conclusion The clinical relevance of this scoring system remains to be evaluated prospectively in standard clinical conditions