Seasonal variation in deep vein thrombosis

Abstract

All files coded as “suspected” deep vein thrombosis (n=7303, mean (SD) age 63 (19), 58% women, 85% medical patients) or “confirmed” deep vein thrombosis (n=1905, age 65 (20), 54% women, 83% medical patients) were selected from the database of our vascular laboratory over the period 1989-94. Diagnosis was made by a combination of continuous wave Doppler and venous occlusion plethysmography or, from 1992, by B mode venous compression ultrasonography. Inconsistency of the extracted data was found in only seven out of 300 cases (2.3%) by comparison with randomly selected original charts.