Does specificity of electrodiagnostic test referrals predict for test outcome in children?

Introduction/Aims Electrodiagnostic testing (EDX) is important in evaluation of pediatric neuromuscular disease. Non-specific referrals have emerged as a leading reason for EDX in recent years. We examine whether referral-specificity is predictive of test outcomes in children. Methods EDX referrals and outcomes were audited over a 7-year period from 2013 to 2020 at CHI-Crumlin. Pre-test details were coded and compared to EDX outcomes using multinomial logistic regression. Results EDX studies were performed in 702 children (median age 10.2 years). In 36% of patients, EDX-referrals did not specify any pre-test diagnosis. Mononeuropathy (24%) and polyneuropathy (15%) were the leading pre-specified diagnoses as well as the most common test outcomes. Neurology and orthopedics/plastic surgery contributed the majority of referrals. Metabolic medicine and hematology/oncology were most likely to pre-specify a working diagnosis and were the specialties with both the highest proportion of abnormal outcomes and referral accuracy. EDX abnormality was present in 42% of patients and was predicted by specificity of referral and the absence of pain as a leading symptom. The accuracy of specified pre-test diagnoses was highest for suspected anterior horn cell disorders (67%). Accuracy of referrals, as well as abnormal test outcomes, were negatively predicted by the presence of pain as a leading symptom. Discussion EDX is informative in children but the likelihood of abnormal test-outcomes is diminished when a pre-specified working diagnosis is lacking or when the primary reason for referral is pain.

Automated summary

This study examined the predictability of test outcomes based on the specificity of referrals for pediatric electrodiagnostic testing (EDX). The results showed that the specificity of referrals was related to referral accuracy and abnormal test outcomes. Lack of specified pre-test diagnosis or the primary symptom being pain decreased the likelihood of abnormal test outcomes.