ABA Sleep Medicine common mistakes
ABA Sleep Medicine · Understand the traps and how to avoid them.
Assigning an AHI-based severity label from a home sleep apnea test when the study was negative or inadequate, instead of recognizing that a negative/inconclusive HSAT in a patient with high pretest probability requires in-lab polysomnography.
Candidates treat HSAT as interchangeable with PSG and apply the same AHI cutoffs, forgetting HSAT underestimates events because total sleep time is estimated rather than measured.
What to do instead
Before assigning severity, confirm the denominator: on HSAT use recording time and note the underestimation bias; state explicitly that a negative HSAT in a high-pretest-probability patient does not exclude OSA and refer for PSG.
Scoring hypopneas using the 4%-desaturation rule in one part of a study and the 3%-plus-arousal rule in another, producing an internally inconsistent AHI.
Candidates memorize both definitions but forget that the AASM allows either rule, not a mix, and that the chosen rule must be applied consistently and stated in the report.
What to do instead
Pick one hypopnea rule per study (typically 3%-or-arousal for clinical scoring), apply it to every event, and document the rule used so the AHI is reproducible.
Diagnosing narcolepsy type 1 on the basis of an abnormal MSLT alone without confirming the preceding PSG showed adequate sleep and without checking for REM-suppressing medications or insufficient sleep.
Candidates anchor on mean sleep latency and sleep-onset REM periods and skip the mandatory confounders (drug washout, sleep deprivation, circadian phase, prior-night PSG criteria).
What to do instead
Walk a checklist before interpreting the MSLT: prior PSG total sleep time adequate, no REM-suppressing drugs for the required washout, no shift work, and then apply the MSLT criteria plus CSF hypocretin or cataplexy for type 1.
Misclassifying NREM parasomnias as REM sleep behavior disorder because the event occurred at night with movement, without checking the sleep stage on the epoch and the timing relative to sleep onset.
Candidates rely on the clinical vignette (acting out, thrashing) and ignore that disorders of arousal arise from slow-wave sleep early in the night, whereas RBD arises from REM with atonia loss later in the night.
What to do instead
For any nocturnal event, first identify the stage and time of night on the PSG: N3-early-night events favor disorders of arousal; REM-late-night events with preserved tone favor RBD; confirm with EMG atonia criteria.
Treating a low AHI as excluding clinically significant sleep-disordered breathing in a patient with obesity hypoventilation or COPD, instead of evaluating awake and sleep gas exchange.
Candidates equate OSA severity with AHI and forget that hypoventilation and nocturnal hypoxemia can occur with a modest AHI and require PaCO2/bicarbonate and oximetry or capnography.
What to do instead
For patients with obesity, neuromuscular disease, or COPD, add awake ABG/bicarbonate and sleep CO2 monitoring; diagnose hypoventilation by the PaCO2 criteria independent of AHI.
Clearing a patient for surgery based on a STOP-BANG score alone, or ordering a sleep study that will not return before the operating date, rather than applying a perioperative risk pathway.
Candidates treat screening tools as diagnostic and forget that the perioperative question is risk mitigation (postoperative monitoring, opioid-sparing, CPAP continuation), not a new OSA diagnosis.
What to do instead
Use the screen to stratify, then act: continue CPAP perioperatively, plan postoperative monitoring and opioid-sparing analgesia for high-risk patients, and defer elective surgery only when the pathway requires it.
Applying adult diagnostic thresholds and adult MSLT norms to a child or adolescent with suspected narcolepsy or sleep apnea.
Candidates memorize adult AHI and MSLT cutoffs and do not adjust for pediatric scoring rules, shorter MSLT norms, or the higher prevalence of insufficient sleep and delayed sleep phase in adolescents.
What to do instead
Use pediatric-specific AHI and MSLT interpretive thresholds, require pubertal staging context, and exclude chronic sleep restriction and delayed sleep phase before labeling hypersomnolence.
Diagnosing insomnia disorder from a single night's poor sleep or from sleep-diary data alone without confirming the chronicity, frequency, and daytime-impairment criteria and excluding another sleep disorder.
Candidates focus on the complaint and skip the DSM/ICSD duration (≥3 months, ≥3 nights/week) and impairment requirements, and they miss comorbid OSA or circadian misalignment driving the complaint.
What to do instead
Document duration, frequency, and daytime impairment explicitly, obtain a 1–2 week sleep diary plus actigraphy when circadian phase is in question, and screen for OSA/RLS before finalizing insomnia disorder.
Interpreting periodic limb movements on PSG as the cause of a patient's insomnia or daytime sleepiness without checking the arousal index and the alternative diagnoses.
Candidates see a PLM index above threshold and stop there, forgetting that PLMS are common and often incidental and that RLS is a clinical diagnosis, not a PSG diagnosis.
What to do instead
Report the PLM index with the associated arousal index, treat only when movements are symptomatic or arousals are frequent, and diagnose RLS clinically from the urge-to-move criteria.
Reading a multiple sleep latency test or maintenance of wakefulness test as a pass/fail number without accounting for the test's purpose and the patient's sleep-wake history in the preceding weeks.
Candidates conflate the MSLT (measures sleepiness, used for narcolepsy/idiopathic hypersomnia) with the MWT (measures wakefulness, used for treatment response), and they overlook that recent sleep debt shifts both.
What to do instead
State which test answers which question, verify adequate sleep and drug washout beforehand, and interpret results alongside the clinical history rather than as an isolated cutoff.