What does an Epworth Sleepiness Scale (ESS) score of 7 indicate?

Epworth Sleepiness Scale Score of 7: Interpretation and Clinical Significance

An Epworth Sleepiness Scale (ESS) score of 7 indicates normal daytime sleepiness and does not suggest excessive daytime sleepiness or obstructive sleep apnea based on this measure alone.

Score Interpretation

• ESS scores below 11 are considered normal and do not indicate excessive daytime sleepiness 1, 2
• A score of 7 falls well within the normal range, suggesting the patient does not have significant propensity to doze off during typical daily activities 1
• The ESS was originally validated to distinguish normal subjects from patients with sleep disorders, with normal controls averaging significantly lower scores than those with obstructive sleep apnea, narcolepsy, or idiopathic hypersomnia 1

Clinical Context and Limitations

When ESS Alone Is Insufficient

The ESS has important limitations that must be recognized in clinical practice:

• The ESS cannot confirm or exclude sleepiness as a stand-alone diagnostic tool 3
• Sensitivity ranges from only 0.27-0.72 when screening for obstructive sleep apnea (OSA), with specificity of 0.50-0.76, resulting in excessive false negatives 3
• Self-reported sleepiness is subject to interpretation and bias, and the ESS should prompt direct clinical questioning rather than serve as a definitive assessment 3
• Individual ESS scores show considerable test-retest variability, though classification into normal (<11) versus elevated (≥11) categories demonstrates substantial reliability (Cohen's kappa 0.67) 2

When to Pursue Further Evaluation Despite Normal ESS

Direct clinical questioning supersedes ESS scoring in the following scenarios 3:

• Resistant hypertension with snoring, fitful sleep, or breathing pauses during sleep
• Hypertension with spontaneous or diuretic-induced hypokalemia
• Witnessed apneas during sleep
• Loss of normal nocturnal blood pressure fall
• Obesity with Mallampati class III-IV airway

In these clinical contexts, polysomnography remains indicated regardless of ESS score 3. The ACC/AHA guidelines identify OSA as present in 25-50% of patients with resistant hypertension, making clinical indicators more important than screening questionnaires 3.

Practical Application

• Use the ESS as a screening prompt, not a diagnostic endpoint 3
• A normal ESS score (like 7) does not exclude OSA in patients with clinical risk factors such as resistant hypertension, witnessed apneas, or anatomical findings 3
• Consider supplementing with the Berlin Questionnaire or STOP-BANG if OSA is clinically suspected, though these also have limitations with high false-negative rates 3
• For patients with physical or mental disabilities, the standard ESS may have limited applicability and generate excessive missing responses 4

Test-Retest Reliability

• When ESS is administered twice, approximately 80% of patients with initial scores <11 will have repeat scores <11 2
• This categorical reliability (normal vs. elevated) is comparable to polysomnographic determination of the apnea-hypopnea index (Cohen's kappa 0.26-0.69) 2
• Individual score variability can range from -6.7 to +7.5 points on repeat testing, but categorical classification remains more stable 2