Table 3.

The adjusted time to event Cox Proportional Hazards Models for total RRDI predicting the incidence of CVD event

	CVD events	HR (95% CI) p value
	n (%)	Unadjusted model (1)	Adjusted model (2)	Adjusted model (3)	Adjusted model (4)
Continuous RRDI (10-unit increment)	24/569 (4)	1.24 (1.10 to 1.39) 0.0003	1.22 (1.08 to 1.38) 0.0018	1.23 (1.11 to 1.38) 0.0007	1.22 (1.08 to 1.37) 0.0012
RRDI Category
Tertile 1 (<15.1)	3/187 (2)	REF	REF	REF	REF
Tertile 2 (15.1–<28.4)	7/194 (4)	2.66 (0.68 to 10.34) 0.1586	2.72 (0.70 to 10.59) 0.1481	3.16 (0.81 to 12.40) 0.099	3.22 (0.80 to 12.93) 0.10
Tertile 3 (≥28.4)	14/188 (7)	6.11 (1.72 to 21.72) 0.0052	5.87 (1.60 to 21.46) 0.0075	7.40 (1.97 to 27.73) 0.003	8.99 (2.35 to 34.40) 0.001
P-trend		0.0024	0.0045	0.0017	0.0006

Model (1) is unadjusted. Model (2) is adjusted for age, sex and body mass index. Model (3) is additionally adjusted for age, sex, body mass index and AHI (4% criteria). Model (4) is additionally adjusted for diabetes, HTN, stroke and smoking, average HR and %TST<90%.

AHI 4%, apnoea–hypopnoea index with hypopnoea scored if associated with at least 4% desaturation (events/hour); CVD, cardiovascular disease; HTN, hypertension; RRDI, R-R interval dips index (dips/hour); %TST<90, total sleep time spent less than 90% on oxygen saturation signal (%).