Diagnostic discordance between referral impressions, clinical assessment, and final electrodiagnostic findings

This study evaluated concordance between referral impressions, structured pre-test assessment, and electrodiagnostic findings (EDX), compared the concordance of an electrodiagnostic consultant's (EC) pre-test assessment and the referring clinician's impression with the final EDX diagnosis.

A single-center, prospective observational study enrolled 104 participants over 9 months; 101 completed testing. The EC recorded a diagnostic impression before nerve conduction studies and needle electromyography (EMG). Final diagnoses were categorized using an ICD-10 root-based schema. Referral, pre-test, and final diagnoses were compared using exact agreement between the first-listed primary ICD-10 diagnosis codes.

Among 101 patients (mean age 59 years; 59.4% female), referral-final concordance was 34.7% (35/101), compared with 71.3% (72/101) for EC pre-test-final concordance (matched OR, 6.29; 95% CI, 2.81-16.54; p < 0.001). EDX produced a clinically meaningful diagnostic change in 67 patients (66.3%) and modified management in 53 (52.5%); subsequent implementation was not assessed. The EC pre-test diagnosis differed from the final EDX diagnosis in 29 cases (28.7%).

EDX frequently identified diagnoses that differed from referral impressions and sometimes differed from the consultant's pre-test assessment. The higher pre-test-final concordance reflects within-clinician agreement after a focused history and examination; it does not establish that the electrodiagnostic consultant is more diagnostically accurate than referring clinicians.

This single-center exploratory study supports the clinical value of a focused pre-test assessment and of EDX as a diagnostic consultation. Larger, multicenter studies using independent assessment are needed.