The development and validation of the Norfolk QOL-DN, a new measure of patients' perception of the effects of diabetes and diabetic neuropathy.

Background: This study was designed to develop and validate a patient-reported outcomes measure, sensitive to the different features of diabetic neuropathy (DN)—small fiber, large fiber, and autonomic nerve function. Methods: The review of 1,000 structured patient interviews guided the development of 28 items pertaining specifically to the symptoms and impact of large fiber, small fiber, and autonomic nerve function. These items, in addition to 14 generic health status items and five general information items formed the 47-item Norfolk Quality of Life Questionnaire–Diabetic Neuropathy (QOL-DN). Items were grouped according to small fiber, large fiber, and autonomic nerve function, symptoms, and activities of daily living (ADL). Scores in individual domains were aggregated to provide a total score. Item groupings were tested for their ability to distinguish between the effects of specific nerve fiber deficits in 262 subjects—81 healthy controls (C), 86 controls with diabetes (DC), and 95 patients with DN—u...