Abstracts

Rationale:
Recent epilepsy quality measures recommend screening for depression and anxiety at every epilepsy visit and specifically endorse the Patient Health Questionnaire-2 (PHQ-2) and Generalized Anxiety Disorder-2 (GAD-2) ultra-brief screeners.  Thus, it is important to assess how symptom detection may be affected by use of these and other ultra-brief screeners, compared to slightly longer, well-validated instruments: Neurological Disorders Depression Inventory-Epilepsy (NDDI-E) and Generalized Anxiety Disorder-7 (GAD-7). The primary objective was to compare symptom detection by brief versus ultra-brief depression and anxiety screeners administered in a large real-world epilepsy clinic sample.
Method:
This was a prospective, cross-sectional assessment of consecutive patients of 3 adult epileptologists in a tertiary epilepsy practice who completed the GAD-7 and NDDI-E with embedded ultra-brief scales (GAD-2; GAD-Single Item: GAD-SI; NDDI-E 2 item: NDDIE-2) on a tablet, and who also had ultra-brief PHQ-2 (yes/no version) documented in the medical record by clinic nursing staff. Demographics, epilepsy diagnosis and seizure freedom were collected. Prevalence of anxiety and depression were calculated for each instrument (based on original validation literature cut-points) and by epilepsy/6-month seizure free status. Receiver operating curves (ROC) were calculated using the longer instruments as “gold standard,” and concordance correlation coefficients were calculated comparing the ultra-brief to brief anxiety and depression instruments, respectively.
Results:
Among N=422 individuals (19.2% non-Caucasian or Hispanic, 54% women, mean age 45 years, 62.6% focal epilepsy), the prevalence of anxiety by GAD-7 was 24% (95% CI 0.21-0.29) and depression by NDDI-E was 20% (CI 0.16-0.24). Seizure freedom was associated with lower anxiety and depression prevalence than continued seizures (Table). Demographic variables were not associated with anxiety or depression symptom prevalence. The ROC curves for the NDDIE-2, GAD-2 and GAD-SI had acceptable areas under the curve (0.96, 0.98, 0.89 respectively, Figure). The yes/no PHQ-2 instrument had only 1 positive screen among 422 participants, in a patient who was not one of the 86 individuals with a positive NDDI-E screen. Other than poor concordance between the PHQ-2 and NDDI-E, the other screener pairs had acceptable concordance coefficients (GAD-7 & GAD-2 0.92 [CI 0.91-0.94], GAD-7 & GAD-SI 0.81 [CI 0.78-0.84], NDDI-E & NDDIE-2 0.79 [CI 0.76-0.82]).
Conclusion:
In this sample, interview-administered yes/no PHQ-2 instrument had exceedingly low sensitivity compared to the NDDI-E.  Further investigation is warranted to assess if poor detection is due to characteristics of the yes/no PHQ-2 in epilepsy samples, or method of nursing interview administration in this clinic. The other ultra-brief anxiety and depression instruments demonstrated good concordance with the longer, well-validated instruments and may be beneficial to use in clinical practice.
Funding:
:NIH TR001420, NS107197, 2KL2TR001421-05