PSQ Score Threshold for Sleep Study Referral
A Pediatric Sleep Questionnaire (PSQ) score ≥0.33 should trigger referral for polysomnography in children with suspected obstructive sleep apnea. This threshold represents the validated cutoff that balances sensitivity and specificity for identifying sleep-disordered breathing requiring objective assessment 1, 2.
Evidence-Based Threshold
The PSQ score of 0.33 is the established diagnostic cutoff derived from validation studies showing 85% sensitivity and 87% specificity for identifying polysomnographically-confirmed sleep-related breathing disorders in children aged 2-18 years 2.
The American Thoracic Society references this 0.33 threshold as the definition of OSA in clinical research, with one study defining OSA remission after bariatric surgery as improvement in PSQ scores below this cutoff 1.
This threshold was validated against polysomnography showing strong association with SRBD diagnosis (P<0.0001) in logistic regression models accounting for age and gender 2.
Clinical Application Algorithm
When to refer for polysomnography:
Any child with PSQ ≥0.33 warrants sleep study referral, particularly when considering adenotonsillectomy or other interventions 1, 2.
Children with PSQ <0.33 but concerning clinical features (tonsillar hypertrophy, witnessed apneas, growth failure, behavioral problems, enuresis) should still be considered for polysomnography, as the PSQ may miss cases 1, 2.
Baseline PSQ scores predict treatment response: Lower PSQ and snoring subscale scores independently predict spontaneous resolution, potentially identifying children who may benefit from watchful waiting rather than immediate intervention 3.
Important Caveats and Limitations
Population-specific performance varies significantly:
The PSQ performs poorly in children with craniofacial anomalies, showing only 70% sensitivity and 40% specificity for detecting AHI ≥5, with even worse performance (65% sensitivity, 31% specificity) in syndromic children 4.
In children already referred for polysomnography due to sleep concerns, the snoring subscale outperforms the full SRBD scale for predicting OSA severity, though neither reliably predicts severe OSA (AHI >25) 5.
The PSQ was not designed to predict OSA severity in children already referred for sleep studies—it functions best as a screening tool in general pediatric populations 5.
Critical clinical context:
Polysomnography remains essential for surgical decision-making: The American Academy of Otolaryngology-Head and Neck Surgery recommends counseling caregivers about tonsillectomy based on abnormal polysomnography findings (typically AHI >1, with AHI >5 warranting intervention in most cases) rather than questionnaire scores alone 1.
Symptomatic resolution lags behind polysomnographic improvement: Only 15% of children with baseline PSQ ≥0.33 achieved symptomatic resolution (PSQ <0.33 with ≥25% improvement) after 7 months of watchful waiting, despite 42% achieving polysomnographic resolution 3.
Practical Implementation
Use the PSQ as a screening gateway:
Screen all children with snoring, behavioral problems, or suspected sleep-disordered breathing using the PSQ 2.
Refer for polysomnography if PSQ ≥0.33 or if clinical suspicion remains high despite lower scores 1, 2.
Consider the snoring subscale specifically when assessing children already being evaluated for sleep disorders, as it shows better predictive value than the full SRBD scale in this context 5.
Do not rely on PSQ alone in craniofacial populations—maintain a lower threshold for polysomnography referral given the high OSA prevalence (40% in one study) and poor screening test performance 4.