What is "success" following surgery for obstructive sleep apnea? the effect of different polysomnographic scoring systems

Objectives/Hypothesis: To illustrate that the diagnosis of obstructive sleep apnea (OSA) is dependent on the polysomnographic scoring criteria used, and the success rates of treatments for OSA are dependent on the defined outcome measures. Study Design: Retrospective case series with prospective reanalysis of polysomnographic data. Methods: Consecutively treated adult patients (N = 40) with moderate to severe OSA having multilevel pharyngeal surgery in 2007 were studied. All patients underwent submucosal lingualplasty and concurrent or previous uvulopalatopharyngoplasty ± palatal advancement. Full polysomnography (PSG) was performed preoperatively and at a mean of 145 days postoperatively. Pre- and postoperative PSG data were analyzed by two different but widely used scoring systems for the apnea-hypopnea index (AHI): The American Academy of Sleep Medicine (AASM) 1999 Chicago criteria and the AASM 2007 recommended criteria. Results: Follow-up PSG data were available in 31 of 40 patients. Successful surgery was defined as a reduction in AHI _Rec <20 with a 50% reduction from the patient's baseline, and in this group the surgical intervention was associated with a 72.2% success rate. If, however, differing AHI metrics are used or the absolute or percent reduction used to define a successful outcome is changed, then the rate of surgical success is shown to range from 39% to 92%. Conclusions: Different criteria for measuring AHI and defining success following OSA surgery can produce widely conflicting outcome data. Reported results following OSA surgery should be interpreted with this in mind. Using acceptable criteria, multilevel sleep surgery can be demonstrated to be of benefit to the majority of carefully selected patients. Laryngoscope, 2012