"Unequivocally abnormal" vs "usual" signs and symptoms for proficient diagnosis of diabetic polyneuropathy: Cl vs N Phys trial

Objective: To repeat the Clinical vs Neurophysiology (Cl vs N Phys) trial using "unequivocally abnormal" signs and symptoms (Trial 2) compared with the earlier trial (Trial 1), which used "usual" signs and symptoms. Design: Standard and referenced nerve conduction abnormalities were used in both Trials 1 and 2 as the standard criterion indicative of diabetic sensorimotor polyneuropathy. Physician proficiency (accuracy among evaluators) was compared between Trials 1 and 2. Setting: Academic medical centers in Canada, Denmark, England, and the United States. Participants: Thirteen expert neuromuscular physicians. One expert was replaced in Trial 2. Results: The marked overreporting, especially of signs, in Trial 1 was avoided in Trial 2. Reproducibility of diagnosis between days 1 and 2 was significantly (P = .005) better in Trial 2. The correlation of the following clinical scores with composite nerve conduction measures spanning the range of normality and abnormality was improved in Trial 2: pinprick sensation ( P = .03), decreased reflexes ( P = .06), touch-pressure sensation (P = .06), and the sum of symptoms (P = .06). Conclusions: The simple pretrial decision to use unequivocally abnormal signs and symptoms - taking age, sex, and physical variables into account - in making clinical judgments for the diagnosis of diabetic sensorimotor polyneuropathy (Trial 2) improves physician proficiency compared with use of usual elicitation of signs and symptoms (Trial 1); both compare to confirmed nerve conduction abnormality.