Sleep studies come in two main types: in-lab polysomnography and home sleep apnea testing. In lab vs home sleep study selection depends on what’s being evaluated. Home tests are convenient and cheaper but have limitations.
In-lab polysomnogram (PSG)
What it measures:
- EEG (brain waves) — sleep stages
- EOG (eye movements)
- EMG (chin, leg movements)
- EKG
- Airflow and breathing effort
- Oxygen saturation
- Body position
- Audio and video monitoring
Comprehensive assessment of all sleep parameters.
Home sleep apnea test (HSAT)
What it measures:
- Airflow and breathing effort
- Oxygen saturation
- Heart rate
- Body position
- Sometimes additional channels
No EEG — can’t measure sleep stages or determine actual sleep time vs time in bed.
When in-lab is appropriate
- Suspected non-OSA sleep disorders (parasomnias, narcolepsy, RLS)
- Significant medical comorbidities
- Suspected central sleep apnea
- CPAP titration
- Negative HSAT with high suspicion
- Children
When HSAT is appropriate
- High pre-test probability of OSA
- No major comorbidities
- Ability to perform self-test
- Cost considerations
- Patient preference for home environment
Cost comparison
- In-lab: $1000-3000 typically
- HSAT: $300-800 typically
- Insurance coverage varies; HSAT increasingly required first
Limitations of HSAT
- Can underestimate AHI (no actual sleep time measurement)
- Can’t diagnose non-OSA sleep disorders
- Less reliable in patients with comorbidities
- Negative HSAT doesn’t rule out OSA in high-suspicion patients
Frequently Asked Questions
Which test should I get?
Depends on clinical situation. Sleep specialist recommends.
Is HSAT as accurate as in-lab?
Adequate for diagnosing significant OSA in appropriate patients. Less comprehensive overall.
Does insurance prefer one?
Increasingly requiring HSAT first for cost reasons. In-lab when HSAT inadequate.
Can HSAT miss sleep apnea?
Yes, can underestimate severity. Negative HSAT in high-suspicion patient warrants in-lab.
What’s a split-night study?
Combined diagnostic and CPAP titration in one in-lab night.
The bottom line on sleep studies
Both have roles. HSAT for straightforward OSA evaluation; in-lab for complex cases. Sleep specialist guides selection.