Variability in leg compression provided by gradient commercial stockings.

ABSTRACT

BACKGROUND: Compression stockings are commonly prescribed by physicians for lower extremity edema and venous insufficiency. However, no data are available for clinicians to assess the relative quality of various brands, particularly low-cost generics now available directly to consumers through the Internet. We examined the actual compression provided by gradient stockings from multiple manufacturers. METHODS: A total of 36 class 2 (20-30 mm Hg) men's medium-sized below-knee compression stockings from six different manufacturers (n = 6 of each brand) with approximately the same quality and materials were chosen to be studied. Identifying brand names were removed, and they were randomly and blindly tested by a technician in accordance with accepted industry standards. A calibrated constant rate of extension tensile instrument (Zwick Z010; Zwick Roell, Ulm, Germany) was used, and the tension generated by the stockings at the ankle and calf was measured using minimum, average, and maximum circumference sizes. All measurements were performed in duplicate. RESULTS: The compression pressures generated by the stockings were almost all within the stated range of 20 to 30 mm Hg at the ankle, but all except one were below 20 mm Hg at the calf. There were also significant differences between manufacturers at both the ankle and the calf (P < .0001). The expected pressure reduction between the two locations varied, but one stocking had only a minimal 2 mm Hg (8%) gradient, which was significantly less than all of the other tested brands and below the recommended 20% to 50% reduction. Cost analysis demonstrated that the discount brands were significantly lower in price but provided absolute compression and pressure gradients similar to those of the more expensive brands. CONCLUSIONS: There is significant variability among stockings, both in the absolute pressures and in the pressure gradients generated from the ankle to the calf, thought to be functionally important for venous flow. The cheaper stockings offered the same degree of compression and pressure gradient as the more expensive brands. These results suggest the need for manufacturing standards in the United States and a revision in labeling requirements to mandate more accurate and complete pressure disclosures.