. 2021 Aug 6;23(8):1016. doi: 10.3390/e23081016

Table 3.

Results of the partial correlation study in the test set between features selected for each subset and the polysomnographic indices considered.

BISP_Classic Features
PSG Index	VLF_f2m		*LF_BE₂*		*HF_PE*
PSG Index	*ρ_S*	p-Value	*ρ_S*	p-Value	*ρ_S*	p-Value
AHI	0.274	<<0.01	−0.185	<<0.01	−0.112	0.002 *
OAHI	0.261	<<0.01	−0.149	<<0.01	−0.097	0.008
OAI	0.167	<<0.01	−0.105	0.004 *	−0.064	0.079
ODI	0.215	<<0.01	−0.123	0.001 *	−0.054	0.138
#Awakenings	−0.075	0.039	−0.027	0.461	−0.020	0.586
WASO	−0.003	0.929	0.065	0.076	−0.022	0.538
%N1	0.089	0.014	−0.071	0.052	−0.030	0.404
%N2	−0.034	0.357	0.099	0.007 *	0.013	0.715
%N3	0.034	0.355	−0.025	0.497	−0.044	0.23
%REM	−0.125	0.001	−0.052	0.154	0.059	0.108
TAI	0.213	<<0.01	−0.158	<<0.01	−0.115	0.002 *
BISP_Specific Features
PSG Index	*BW2_RP_Diag*		*BW2_BE₁*		*BWRes_B_min*		*BWRes_BE₃*
PSG Index	*ρ_S*	p-Value	*ρ_S*	p-Value	*ρ_S*	p-Value	*ρ_S*	p-Value
AHI	0.308	<<0.01	−0.180	<<0.01	0.054	0.136	0.045	0.214
OAHI	0.261	<<0.01	−0.180	<<0.01	0.098	0.007 *	0.028	0.435
OAI	0.177	<<0.01	−0.173	<<0.01	0.071	0.051	0.058	0.112
ODI	0.247	<<0.01	−0.139	0.001	0.019	0.61	0.072	0.047
#Awakenings	−0.033	0.372	−0.001	0.994	−0.006	0.876	0.035	0.331
WASO	0.071	0.05	0.078	0.031	−0.018	0.622	0.056	0.126
%N1	0.107	0.003 *	−0.061	0.093	0.023	0.527	0.028	0.441
%N2	−0.061	0.091	0.008	0.837	0.048	0.184	0.059	0.104
%N3	0.053	0.147	0.008	0.817	−0.075	0.04	−0.092	0.011
%REM	−0.139	0.001	0.048	0.192	−0.007	0.855	0.013	0.722
TAI	0.225	<<0.01	−0.144	<<0.01	0.068	0.062	0.068	0.06

PSG: polysomnographic; AHI: Apnea–Hypopnea Index; OAHI: Obstructive AHI; OAI: obstructive apnea index; ODI: oxygen desaturation index; #Awakenings: number of awakenings during total sleep time; WASO: wake after sleep onset; %N1: percentage of sleep spent in N1; %N2: percentage of sleep spent in N2; %N3: percentage of sleep spent in N3; %REM: percentage of sleep spent in REM; TAI: total arousal index. Those p-values below 10⁻⁴ appear as << 0.01. * Non-significant after Bonferroni correction. Statistically significant correlations (p-value < 0.01 after Bonferroni correction) appear in bold.