Polysomnography and sleep position, a Heisenberg phenomenon?: A large-scale series

Background The severity of position-dependent obstructive sleep apnea (POSA) depends on the nonsupine and supine apnea–hypopnea index (AHI) as well as the time spent in supine position. The latter in particular is susceptible to variation. Several small-scale studies suggest that wearing polysomnography (PSG) apparatus leads to an increase in supine sleeping position.