What Epworth Sleepiness Scale (ESS) score is significant to refer a patient for further evaluation or treatment?

Epworth Sleepiness Scale Referral Thresholds

An Epworth Sleepiness Scale (ESS) score of 11 or greater is significant enough to warrant referral for further sleep evaluation, especially when accompanied by other clinical symptoms suggestive of a sleep disorder. 1, 2

Understanding the ESS Score Interpretation

The ESS is a validated tool for assessing daytime sleepiness, but its interpretation should be considered within the clinical context:

• ESS Score < 11: Generally considered normal or mild sleepiness
• ESS Score ≥ 11: Indicates excessive daytime sleepiness requiring further evaluation 3, 4

Clinical Decision Algorithm for Referral

Primary Criteria for Referral:

1. ESS Score ≥ 11 with any of the following:

   • Snoring, witnessed apneas, or fitful sleep
   • Morning headaches or dry mouth upon awakening
   • Obesity or increased neck circumference
   • Hypertension or cardiovascular disease

2. ESS Score ≥ 9 with any of the following:

   • History of motor vehicle crashes or near-misses attributed to sleepiness
   • Moderate to severe daytime sleepiness (falling asleep unintentionally during daily activities)
   • Occupational safety concerns (e.g., commercial drivers, machinery operators)

Secondary Considerations:

• ESS Score < 11 but with significant clinical symptoms may still warrant referral
• ESS Score ≥ 17 indicates severe sleepiness requiring urgent evaluation 1

Important Clinical Pearls

Strengths and Limitations of the ESS:

• Test-Retest Reliability: When classified as either normal (<11) or sleepy (≥11), the ESS has substantial reliability (Cohen's kappa = 0.67) 3
• Administration Method: Physician-administered ESS may be more accurate than self-administered ESS (higher completion rates and better correlation with objective measures) 5
• Correlation with MSLT: ESS scores correlate negatively with Multiple Sleep Latency Test results, though the correlation is modest (rho = -0.37) 4

Common Pitfalls to Avoid:

1. Relying solely on ESS: The ESS alone is insufficient to identify high-risk drivers or diagnose specific sleep disorders 1
2. Ignoring clinical context: ESS scores should be interpreted alongside clinical history and examination
3. Missing comorbid conditions: Conditions like obesity hypoventilation syndrome may present with elevated ESS scores 1
4. Failing to consider medication effects: Many medications can affect sleep and daytime alertness 2

Specific Sleep Disorders and ESS Thresholds

Obstructive Sleep Apnea (OSA):

• ESS ≥ 10 was used as inclusion criteria for clinical trials of modafinil in OSA 6
• ESS ≥ 11 has good sensitivity for detecting clinically significant OSA 7

Narcolepsy:

• Typically presents with ESS scores >10, often with additional symptoms like cataplexy, sleep paralysis, or hypnagogic hallucinations 6

Shift Work Disorder:

• ESS may not accurately reflect sleepiness in shift workers due to circadian misalignment 2
• Additional assessment tools may be needed

Follow-up Recommendations

• Patients with ESS ≥ 11 should be referred for sleep specialist evaluation and possible polysomnography
• Patients with ESS 9-10 should be evaluated for other clinical indicators of sleep disorders
• For patients with elevated ESS scores, consider screening for common comorbidities (hypertension, diabetes, depression)

Remember that while the ESS is a useful screening tool, clinical judgment remains essential in determining the need for referral and further evaluation of sleep disorders.