A comparison between auto-scored apnea-hypopnea index and oxygen desaturation index in the characterization of positional obstructive sleep apnea

Figures & data

Table 1 Descriptive data for the 184 patient records analyzed for the AHI vs ODI comparisons and the 132 records used for the POSA analysis

Demographic and anthropomorphic	AHI vs ODI comparisons	POSA analysis
Sample size	184	132
Female, % (n)	52 (95)	48 (64)
Age (years), mean ± SD	46±13.7	48±13.0
BMI (kg/m^2), mean ± SD	31±7.1	32±7.0
Neck size (cm), mean ± SD	40±4.7	40±4.3
Comorbidities	% (n)	% (n)
Hypertension	27 (47)	33 (41)
Depression	36 (64)	34 (43)
Restless legs syndrome	18 (31)	19 (24)
Insomnia	14 (24)	14 (18)
Heart disease	6 (11)	8 (10)
Diabetes	6 (11)	8 (10)

Abbreviations: ODI, oxygen desaturation indices; AHI, apnea-hypopnea indices; POSA, positional obstructive sleep apnea.

Table 2 Distributions of sleep-disordered breathing measures across the 184 patient records (mean ± SD)

Measure	AHI	ODI	p
Overall	17.4±18.6	19.2±19.7	0.34
Supine	26.4±24.0	27.4±24.1	0.69
Non-supine	11.9±16.4	14.1±17.5	0.20

Figure 1 Bland Altman plots comparing the AHI vs ODI for (A) overall, (B) supine and (C) non-supine positions (n=184).

Figure 2 Percentage of 184 records with absolute differences between the overall AHI and ODI were ≥5 and ≥10 events/h or absolute difference >50% of the AHI, further stratified by those with mild (n=65), moderate (n=45), or severe OSA (n=31).

Table 3 Agreement between auto-scored AHI vs ODI stratified by sleep position and clinical cut-off (n=184)

Overall
	AHI ≥5	95% CI range		AHI ≥10	95% CI range		AHI ≥15	95% CI range
Positive % agreement	0.99	0.94	1.00	0.96	0.90	0.99	0.96	0.89	0.99
Negative % agreement	0.78	0.63	0.89	0.89	0.80	0.94	0.89	0.82	0.94
Cohen’s ƙ	0.81	0.71	0.91	0.85	0.77	0.92	0.83	0.75	0.91
Supine
	AHI ≥5	95% CI range		AHI ≥10	95% CI range		AHI ≥15	95% CI range
Positive % agreement	0.99	0.96	1.00	0.93	0.87	0.97	0.96	0.90	0.99
Negative % agreement	0.91	0.75	0.98	0.81	0.69	0.90	0.88	0.79	0.94
Cohen’s ƙ	0.92	0.85	1.00	0.76	0.65	0.86	0.85	0.77	0.92
Non-supine
	AHI ≥5	95% CI range		AHI ≥10	95% CI range		AHI ≥15	95% CI range
Positive % agreement	0.98	0.93	1.00	0.95	0.87	0.99	1.00	0.91	1.00
Negative % agreement	0.68	0.57	0.78	0.89	0.82	0.94	0.88	0.82	0.93
Cohen’s ƙ	0.68	0.57	0.78	0.80	0.71	0.89	0.77	0.66	0.87

Abbreviations: AHI, apnea-hypopnea index based on automated analysis and recording time; CI, confidence interval.

Figure 3 Distributions of POSA frequency (n=132) based on AHI vs ODI across all records (overall) and with records stratified by OSA severity based using the ratio of the overall/non-supine (O/NS)≥1.4 and the supine/non-supine (S/NS) ≥2.0.