Difficulty Falling Asleep is Associated with Poorer Therapeutic Outcomes in Unilateral Hypoglossal Nerve Stimulation

Figures & data

Table 1 ISI Score in the Preoperative, Short-Term Follow-Up and Long-Term Follow-Up

	ISI Score M (SD)	ISI 1 M (SD)	ISI 2 M (SD)	ISI 3 M (SD)	ISI 4 M (SD)	ISI 5 M (SD)	ISI 6 M (SD)	ISI 7 M (SD)	Cronbach‘s Alpha for Items 1–7
Preoperative	18.67 ± 5.32	1.93 ± 1.34	2.80 ± 1.00	1.97 ± 1.27	3.50 ± 0.73	2.33 ± 1.21	3.20 ± 1.03	2.97 ± 1.13	0.80
Short-term	12.70 ± 6.62	1.47 ± 1.22	1.97 ± 1.30	1.37 ± 1.03	2.13 ± 1.17	1.73 ± 1.23	1.93 ± 1.46	2.17 ± 1.23	0.88
Long-term	10.08 ± 7.13	1.17 ± 1.19	1.75 ± 0.97	1.42 ± 1.31	1.67 ± 1.23	1.25 ± 1.06	1.00 ± 1.04	1.50 ± 1.38	0.91

Notes: Preoperative, short-term and long-term ISI score and score for each item of the ISI; Cronbach’s alpha for items 1–7; preoperative (α=0.80), short-term (α=0.88) and long-term (α=0.91).

Table 2 Patients and PSG Parameters

	Preoperative Parameter M (SD)	∆ Short-term Follow-up M (SD)	∆ Long-term Follow-up M (SD)
Age (years)	55.40 ± 8.83
BMI (kg/m^2)	29.69 ± 4.32
AHI (n/h)	40.61 ± 12.02	15.01 ± 12.15	10.47 ± 15.38
Cumulative time under apnea and hypopnea (min)	86.30 ± 40.20	34.40 ± 36.31	25.78 ± 34.23
ODI (n/h)	38.72 ± 14.28	9.18 ± 13.21	8.17 ± 15.67
Snoring index (n/h)	244.26 ± 181.14	98.68 ± 115.43	65.81 ± 158.75
t90 (%)	8.85 ± 10.35	2.49 ± 11.47	3.94 ± 10.44
Arousal index (n/h)	23.68 ± 15.59	8.38 ± 16.51	1.23 ± 14.32

Notes: Clinical parameters: age, BMI; PSG-related parameters: AHI, ODI, complete time of apnoea and hypopnea (min), snoring index (n/h) (SI), oxygen desaturation index (n/h) (ODI), percentage of oxygen desaturation lower than 90% (t90) and total number of arousal events per hour (arousal index (n/h)).

Table 3 Correlation Between ISI Score and Each ISI Item and ∆ PSG Parameter (Short-Term)

∆ PSG Parameter	ISI Preoperative	ISI 1	ISI 2	ISI 3	ISI 4	ISI 5	ISI 6	ISI 7
∆ AHI	r	−0.293	−0.013	0.155	−0.311	−0.053	−0.220	−0.152
	p	0.116	0.947	0.413	0.095	0.782	0.243	0.423
∆ Snoring index	r	−0.062	0.199	−0.081	0.152	0.254	0.088	0.224
	p	0.745	0.291	0.671	0.423	0.175	0.644	0.234
∆ Cumulative apnea hypopnea time	r	−0.212	−0.032	−0.107	−0.245	0.124	−0.100	−0.045
	p	0.260	0.866	0.574	0.191	0.513	0.598	0.815
∆ ODI	r	−0.341	0.009	0.158	−0.338	−0.086	−0.177	−0.093
	p	0.065	0.963	0.405	0.068	0.653	0.349	0.626
∆ t90	r	0.077	0.070	−0.041	−0.174	−0.060	−0.179	−0.138
	p	0.686	0.715	0.831	0.359	0.754	0.343	0.467
∆ Arousal index	r	−0.267	−0.212	−0.135	−0.226	−0.280	−0.181	−0.139
	p	0.154	0.261	0.476	0.230	0.134	0.339	0.463

Notes: Correlation between ∆ PSG parameters such as ∆ AHI, ∆ snoring index, ∆ cumulative apnea hypopnea time, ∆ ODI, ∆ t90, ∆ arousal index and each item of the ISI questionnaire in the short-term follow-up.

Table 4 Correlation Between ISI Score and Each ISI Item and ∆ PSG Parameter (Long-Term)

∆ PSG Parameter	ISI Preoperative	ISI 1	ISI 2	ISI 3	ISI 4	ISI 5	ISI 6	ISI 7
∆ AHI	r	−0.647*	−0.217	−0.038	−0.279	0.132	−0.178	−0.186
	p	0.004	0.386	0.880	0.262	0.602	0.479	0.460
∆ ODI	r	−0.693*	−0.106	0.024	−0.238	0.142	−0.124	−0.234
	p	0.001	0.677	0.925	0.341	0.574	0.624	0.350
∆ Snoring index	r	−0.141	0.032	−0.216	0.104	0.404	−0.042	−0.104
	p	0.578	0.898	0.388	0.682	0.096	0.868	0.682
∆ Cumulative apnea hypopnea time	r	−0.411	−0.094	−0.180	−0.278	0.230	−0.026	−0.165
	p	0.090	0.710	0.474	0.264	0.359	0.917	0.512
∆ t90	r	−0.511	−0.143	−0.035	−0.315	0.092	−0.226	−0.184
	p	0.030	0.572	0.890	0.203	0.716	0.366	0.465
∆ Arousal index	r	−0.644*	−0.519	−0.425	−0.084	−0.102	−0.107	−0.076
	p	0.004	0.027	0.078	0.741	0.686	0.671	0.763

Notes: Correlation between ∆ PSG parameters such as ∆ AHI, ∆ snoring index, ∆ cumulative apnea hypopnea time, ∆ ODI, ∆ t90, ∆ arousal index and each separate item of the ISI questionnaire in the long-term follow-up. *Bonferroni corrected significant correlations.

Figure 1 Scatterplot ∆ AHI (n/h) in the long-term follow-up and preoperative ISI item 1.

Figure 2 Scatterplot ∆ ODI (n/h) in the long-term follow-up and preoperative ISI item 1.

Data Sharing Statement

The data underlying this article cannot be shared publicly for the privacy of individuals that participated in the study. The data will be shared on reasonable request to the corresponding authors.