TABLE 2

Rotated component matrix of the principal components analysis of obstructive sleep apnoea severity metrics

Component
“Oxygen desaturation”“Sleep disturbance”
Apnoea–hypopnoea index0.7740.489
Oxygen desaturation index0.8560.311
%TST saturation oxygen <90%0.8420.154
Lowest oxygen saturation (inverted)0.855−0.115
Sleep efficiency (inverted)0.0010.768
Awakening index events·h−10.1150.780
Arousal index events·h−10.4540.734
Variance explained %42.830.1

Extraction method: principal component analysis; rotation method: varimax with Kaiser normalisation. Variables with a loading >0.5 on each component are presented in bold. %TST: percentage of total sleep time.