Abstracts

Rationale: Vitamin D deficiency and osteopenia are well described in the literature for patients on enzyme-inducing antiepileptic drugs (EIAD). More recent studies found that vitamin D deficiency is common among all persons with epilepsy. No guidelines exist for when to order tests or supplementation for patients on EIAD or NEIAD. The purpose of this study is to understand current patterns of diagnosing and preventing or treating vitamin D deficiency and osteopenia to inform future guidelines. The main hypotheses to be tested are whether neurologists were more likely to order vitamin D levels, DEXA scans and supplementation for patients on EIAED. Methods: Electronic medical records of patients at a large center with the following criteria were obtained: diagnosis of epilepsy or seizures, on antiepileptic medications and with the most recent neurology visit between 2009-2015. At least 15 neurologists within the center saw those patients. A randomized subset of 190 charts was reviewed to identify those in which the neurologist had ordered vitamin D levels, DEXA scans, or supplementation, or whether the above were already ordered by a non-neurologist physician. Age, gender, BMI, epilepsy type and Vitamin D levels were recorded and univariate, multivariate and non-parametric analyses were performed on SPSS. Results: Sample size was 190, 102 patients on EIAD and 88 on NEID; 54% women and 46% men, with no difference in gender seen with EIAD and NEIAD. Mean age was greater for EIAD than NEIAD (55 vs. 49 years, p=0.015). Median BMI was higher among EIAD than NEIAD patients (29 vs. 25.5, p=0.006). Generalized epilepsy was more commonly treated with EIAD vs NEIAD (62% vs. 46%, p=0.02). Neurologists ordered Vitamin D levels in 22% of patients; another 12% were already ordered by another physician. Neurologists were more likely to order vitamin D levels for patients on EIAD than NEIAD (32% vs 10.4%, p= < 0.001), and vitamin D levels were more likely to be ordered by either neurologists or other physicians in patients on EIAD than NEIAD (41% vs 26%, p=0.02). Neurologists ordered DEXA scans on 22% of patients, and more likely for EIAD than NEIAD (33% vs 10.4%, p= < 0.001). DEXA scans were more likely to be ordered by either neurologists or other physicians in patients on EIAD than NEIAD (35.3% vs 18.2%, p=0.006). Supplementation was ordered in 23% of patients and was more likely to be ordered by neurologists for patients on EIAD than NEIAD (36% vs 8%, p < 0.001). Neurologists were more likely to order vitamin D levels (odds ratio 2.177, p=0.036), DEXA scans (odds ratio 2.309, p=0.024), and supplements (odds ratio 1.866, p=0.092) on EIAD men than women. Generalized epilepsy did not significantly account for increases in ordering vitamin D for EIADs. Age and BMI were not different among patients for whom neurologists ordered Vitamin D levels, DEXA scans or supplementation. Median total Vitamin D levels were lower in EIAD than NEIAD patients (29 vs 18, p=0.03). Conclusions: Vitamin D level, DEXA scan and supplementation were ordered in moderately low ratios overall and this rate should be higher given the high prevalence of vitamin D insufficiency in all patients with epilepsy. Neurologists and other providers ordered Vitamin D levels and DEXA scans more commonly when patients were on EIAD, which is consistent with prior knowledge about vitamin D deficiency. Low vitamin D levels amongst EIAD compared to NEIAD patients were confirmed in this analysis. Age and BMI did not affect rates of ordering tests or supplementation, but these should be taken into account when evaluating both EIAD and NEIAD patients since they are risk factors for osteopenia. Interestingly, neurologists ordered vitamin D levels, DEXA scans and supplementation more commonly for men than women. Funding: none