Table 1.

Comparison of Loop Gain Values Obtained by Home Sleep Test and Polysomnogram

	Correlation Coefficient	HST LG1	Comparator LG1	Mean Difference (HST − Comparator)	Limits of Agreement of LG1 (95% CI for HST − Comparator)
Standard PSG	0.470*	0.59 ± 0.04	0.66 ± 0.04	−0.08 ± 0.04*	−0.43 to 0.28
Stripped-back PSG
Without arousals	0.637†	0.59 ± 0.04	0.74 ± 0.04	−0.16 ± 0.03†	−0.47 to 0.16
Without sleep state	0.491*	0.59 ± 0.04	0.57 ± 0.03	0.01 ± 0.03	−0.31 to 0.34
Without arousals or sleep state	0.659†	0.59 ± 0.04	0.65 ± 0.03	−0.06 ± 0.03*	−0.34 to 0.22

Definition of abbreviations: CI = confidence interval; HST = home sleep test; LG1 = loop gain at frequency 1/min; PSG = polysomnogram.

Measurements were obtained under standard conditions (incorporating arousals and only non-REM sleep) and stripped back of various EEG-derived measures that are not available in HST. Paired differences are shown as mean ± SEM.

^*P < 0.05.

^†P < 0.001.