Clinical outcomes of electrodiagnostic testing conducted in primary care

Focal and generalized neuropathies, such as carpal tunnel syndrome and diabetic peripheral neuropathy, have high prevalence among the US population. Primary care physicians are increasingly using computerized electrodiagnostic (EDX) testing to evaluate these patients. The impact of this diagnostic modality on physician diagnostic reasoning and patient management has not been directly studied.

Consecutive computerized EDX tests conducted in a primary care clinic were prospectively evaluated using a diagnostic before-and-after study design. The pretest diagnosis and patient management plan were noted before EDX testing. Five clinical outcomes were assessed after the test: (1) test abnormality, (2) confirmation of pretest diagnosis, (3) change in pretest diagnosis, (4) expansion of pretest diagnosis, and (5) change to patient management plan.

One hundred computerized EDX tests were performed among 85 patients. A total of 88 tests were abnormal. The pretest diagnosis was confirmed in 59 tests. The pretest diagnosis was changed by 14 tests and it was expanded by 18 tests. The computerized EDX tests triggered a change in clinical management in 30 cases, with referral to orthopedic surgery and metabolic workup for polyneuropathy as the most common changes.

Computerized EDX testing was clinically valuable in patients with moderate to high pretest probability of common neuropathies such as carpal tunnel syndrome and diabetic polyneuropathy. In approximately one third of cases, the test led to a change in clinical management.