TABLE 1.

The McGill Oximetry Scoring System Devised in Phase 1 and Validated in Phases 2 and 3

Oximetry ScoreCommentCriteriaRecommendation
No. of Drops in SaO2 <90%No. of Drops in SaO2 <85%No. of Drops in SaO2 <80%Other
1Normal study/inconclusive for OSA<300Baseline: stable (<3 clusters of desaturation) and >95%Additional evaluation of breathing during sleep required to rule out OSA
2OSA, mild≥3≤30Three or more clusters of desaturation events14Recommend T&A on the waiting list
3OSA, moderate≥3>3≤3Three or more clusters of desaturation events14Recommend surgery within 2 wk
4OSA, severe≥3>3>3Three or more clusters of desaturation events14Recommend urgent surgery (within days)