Video recordings have low specificity
A prospective cohort study of home sleep video recordings included 58 consecutive children who were 2 to 6 years of age with snoring or labored breathing during sleep. Parents filmed 30 minutes of sleep during “worst breathing” episodes. An expert investigator evaluated the recordings using both a standardized scoring system and subjective impression, and compared these with overnight polysomnography results, finding 94% sensitivity and 68% specificity.9
Two prospective trials compared standardized scoring of home sleep audio recordings with overnight polysomnography testing. The best study, an investigator-blinded RCT, scored 20-minute recordings of “worst breathing” in 59 consecutive children referred for snoring or nocturnal breathing problems, 47% of whom had sleep apnea. Results: PPV=62%, NPV=83%, sensitivity=88%, specificity=52%.7
Abnormal pulse ox is highly predictive
A retrospective, cross-sectional study of 349 children between the ages of 6 months and 18 years determined that abnormal home pulse oximetry studies were highly predictive of obstructive sleep apnea on polysomnography (positive likelihood ratio [LR+]=19.4; CIs not given; posttest probability=97%), but that inconclusive or normal pulse oximetry studies were not predictive of negative polysomnographies (LR+=0.58; CIs not given; posttest probability 47%). Children had been referred for suspected obstructive sleep apnea, and the pretest probability was 60%. Oximetry records were evaluated by a sleep laboratory physician blinded to clinical and polysomnography data.10
Tonsillar-pharyngeal ratio misses mild cases
A prospective cohort study of 35 children compared the tonsillar-pharyngeal ratio measured from lateral neck x-rays to overnight polysomnography. X-ray measurements predicted moderate or severe obstructive sleep apnea on polysomnography (sensitivity=96%, specificity=82%, PPV=92%, NPV=90%), but did not accurately differentiate normal children from those with mild obstructive sleep apnea.11
Recommendations from others
The American Academy of Pediatrics recommends that children be screened during well child visits for regular snoring or apnea episodes during sleep. Children with positive screens should have an overnight polysomnography. Children with confirmed obstructive sleep apnea should be referred to a sleep medicine specialist to consider continuous positive airway pressure therapy during sleep, or to an otolaryngologist for possible surgery (tonsillectomy or adenoidectomy).2