Performance characteristics of obstructive sleep apnea screening instruments in adults with epilepsy.

Rationale

Obstructive Sleep Apnea (OSA) is a highly prevalent, but often overlooked comorbidity in adults with epilepsy (AWE). Screening instruments widely used in general populations include STOP (Snoring, Tiredness, Observed apneas, high blood Pressure) and STOP-BANG (+BMI, Age, Neck circumference (NC), and Gender). Novel screens such as STOP-BAG2 may improve OSA risk stratification, but validity and performance characteristics of OSA instruments have not been studied in large AWE populations.

Methods

We analyzed 724 AWE with STOP-BANG data available within 1 year of polysomnography (PSG). The primary outcome was apnea-hypopnea index (AHI) ≥ 5. We compared STOP, STOP-BANG, STOP-BAG, STOP-BAG2, and reweighted STOP-BANG2. Sensitivity, specificity, positive predictive value, negative predictive value, and area under the curve (AUC) were estimated. Instrument performance was compared by differences in AUC, with optimal cutoffs identified by the Youden index and internally validated using 1,000 bootstrap resamples. Seizure severity and frequency were assessed with the Liverpool Seizure Severity Scale.

Results

Higher STOP, STOP-BANG, STOP-BAG, and STOP-BAG2 scores were associated with AHI ≥ 5. STOP-BANG, STOP-BAG, STOP-BAG2, and STOP-BANG2 were superior to STOP. STOP-BAG2 and STOP-BANG2 showed the strongest predictive power, each with an AUC of 0.70. At the Youden cutoff, STOP-BAG2 yielded 67 % sensitivity and 65 % specificity, while STOP-BANG2 yielded 72 % sensitivity and 60 % specificity. STOP-BAG2 was superior to STOP-BANG and STOP-BAG (p = 0.003 and p = 0.001, respectively) and did not differ from STOP-BANG2 (p = 0.84).

Conclusions

STOP-derived instruments showed limited-to-moderate discrimination for PSG-defined OSA. The continuous weighted models had the highest AUCs, but the gain over categorical scores was modest, and their selected cutoffs would miss a clinically relevant portion of OSA cases.