"Unequivocally Abnormal" vs "Usual" Signs and Symptoms for Proficient Diagnosis of Diabetic Polyneuropathy: Cl vs N Phys Trial.

Abstract

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.