The percentage of patients undergoing treatment of incompetent lower extremity perforator veins with surgical or ablation treatment (radiofrequency, laser, mechanochemical, chemical, or embolic adhesive) who have CEAP clinical severity of disease C5 or C6 (venous ulcer or history of ulcer), and not less severe C1-4 disease. Rationale: Perforator vein treatment has only been shown to benefit patients with venous ulcers or a history of ulcers, but is often applied to patients with less severe disease unnecessarily. This measures documents appropriate patient selection and effective cost reduction.