Validation of self-administered questionnaire for study of peripheral neuropathy

An eight-item, self-administered questionnaire for the ascertainment of peripheral neuropathies was validated with 19 persons who had neuropathy confirmed by neurologists' examinations and electrodiagnostic studies, and with 37 persons without known neuropathy. The results from cases and neurology clinic controls suggested a two-stage screening definition for cases of peripheral neuropathy: the classification as cases of all persons who required help getting out of a chair one or more days/week and, among those not requiring help, who had a symptom score of zero or more based on the formula Si = -2.6 + 0.8 (frequency of cramps in arms or legs) + 0.5 (frequency of paresthesias in arms, hands, legs, or feet). This case definition resulted in a sensitivity of 76.5% and a specificity of 93.3% when applied to the original data from which it was developed. The statistical technique of cross-validation suggested an upward bias in these estimates of sensitivity and specificity of 12% and 20%, respectively. The model had a specificity of 100% when tested independently with medical office controls. The authors discuss the use of the questionnaire in cross-sectional epidemiologic studies.