Abstracts

Rationale: Despite a verified biomarker for diagnosis (video EEG), as well as guidelines for diagnosis from the International League Against Epilepsy (ILAE), validity still varies in ICD-10 coding for PNES. We performed a diagnostic accuracy study of the 10th International Classification of Diseases (ICD10) code to determine the sensitivity and specificity of F44.5 for psychogenic non-epileptic seizures (PNES). Methods: The study population consisted of 876 Veterans, obtained from an ongoing study in the Veterans Administration of post 9/11 Veterans with PNES. The positive predictive value (PPV) was calculated for ICD-10 Code F44.5 using video EEG diagnosed PNES as the true positive group. Preliminary data is presented on 100 Veterans randomly selected from this cohort. Results: Among 100 patients coded for ICD 10 F44.5, adjudication identified 55 veterans with PNES: 11 (11%) definite, 16 (16%) probable, and 28 (28%) possible, 3 (3%) with epilepsy, and 42 (42%) without PNES or epilepsy. The PPV of ICD-10 code F44.5 was 61% when coded for by any provider and increased to 73% when coded by a neurologist. Conclusions: Proper coding for PNES has immediate and long-term implications in patient care, including: communication amongst a multidisciplinary team, access to care and initiation of proper treatment, as well as future research studies. These preliminary results indicate discrepancy in coding for conversion disorders with convulsions. The PPV seems to depend on the level of department specialization. Further studies are warranted to confirm or refute these findings. Funding: Department of Defense office of Congressionally Directed medical Research Programs Epilepsy Research Program EP160049