Half of OSAS patients suffer from positional OSAS
Scientific research has shown that many OSAS patients experience increased airway obstruction during sleep when lying on their backs than when lying on their sides4. When an individual experiences an increased level of airway obstruction when lying on their back as compared to any other position, it is known as Positional OSAS (POSAS). POSAS is defined as OSAS whose Apnea Hypopnea Index (AHI) level is at least twice as high when lying on their back (supine) than in any other position (AHI supine > 2 x AHI other positions).
A study of over 600 patients conducted in The Netherlands and Israel has shown that roughly half (56%) of the light and moderate OSAS patients indeed have POSAS5,6. On top of this, 30% of patients have a higher AHI when supine than in any other position, only not twice as high5,6. The incidence of POSAS is much higher among light and medium OSAS (5 ≤ AHI < 30) than by severe OSAS (AHI > 30)7.