Medical technology assessment of polysomnography, type 2: full PSG at home – night to night variability in Apnea Hypopnea Index (AHI) and Periodic Limb Movement Index (PLMI)

Abstract

Polysomnography (PSG) in a clinical setting (CPSG, type 1) is time consuming and expensive. Type 2, i.e. full PSG at home, is thought to be a good alternative, but has never been evaluated in terms of regular Medical Technology Assessment (MTA). In some countries this lack of MTA precludes reimbursement for PSG type 2. This communication is part of a series of posters which add up to MTA of PSG, type 2, and deals with night to night sleep variability. This study is designed to investigate the differences between the first and the second night, during two full PSG’s type 2, on AHI and PLMI. Retrospective case control study of 325 patients (49,1% male, mean age = 45.0, SD = 16.7) who underwent full PSG type 2 for two consecutive days. The number of patients who were diagnosed with Sleep Related Breathing Disorder (SRBD) ( n = 54), and those who were diagnosed with Sleep Related Movement Disorder (SRMD) ( n = 47), were compared with the total group of patients on the parameters AHI and PLMI. Looking at the two nights and a mean AHI less than 10 per hour, which implies no or a mild Obstructive Sleep Apnea Syndrome (OSAS), we found no internight variability. Looking at the two nights and a mean AHI greater than 15 per hour, which implies moderate or severe OSAS, we found high internight variability. The results referring to the group of patients who are diagnosed for SRMD (with a PLMI cut-off point of 8–10 per hour) are similar. On the basis of this study, it can be concluded that one measurement would be valid in cases of no or mild disturbances in either Breathing Disorder or Movement Disorder. In order to determine the severity of OSAS or PLMD of clinical importance, a two-night PSG, type 2, is mandatory to give a valid diagnosis.