Sleep Apnea Clinical Score (SACS, Flemons)
Sleep Apnea Clinical Score (Flemons 1994): adjusted neck circumference = measured neck (cm) + 4 (hypertension) + 3 (habitual snoring) + 3 (nocturnal gasping/choking).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Measured neck circumference
- 42 cm
- Hypertension
- Yes
- Habitual snoring
- Yes
Result: Adjusted neck circumference 49 cm — high pretest probability of OSA (> 48) — consider expedited polysomnography.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Bands
- ≤ 43 low, 43–48 intermediate, > 48 high pretest probability of obstructive sleep apnea. An anthropometry-driven triage rule; decision support, not a polysomnography order.
What you enter
- Measured neck circumference
- Hypertension (+4)
- Habitual snoring (+3)
- Nocturnal gasping / choking (+3)
How this is calculated
- Formula
- Adjusted neck circumference = measured neck (cm) + 4 (hypertension) + 3 (habitual snoring) + 3 (nocturnal gasping/choking).
Flemons WW, Whitelaw WA, Brant R, Remmers JE. Likelihood ratios for a sleep apnea clinical prediction rule. Am J Respir Crit Care Med. 1994;150(5 Pt 1):1279-1285. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.