Table 6.

Comparison of adjusted Cox proportional hazards models for primary outcome using cluster membership versus OSA severity as measured by AHI (n=1036^*, see legend for analyses by none vs mild, moderate and severe groups)

Variables	Cluster membership, CPAP use and Framingham risk score			AHI severity, CPAP use and Framingham risk score
Cluster label	HR	95% CI	p Value	HR	95% CI	p Value
Mild	Ref	–	0.0265	–	–
PLMS	2.02	1.32 to 3.08		–	–
NREM and poor sleep	1.28	0.85 to 1.94		–	–
REM and hypoxia	1.37	0.89 to 2.11		–	–
Hypopnoea and hypoxia	1.74	1.02 to 2.99		–	–
Arousal and poor sleep	1.79	0.97 to 3.29		–	–
Combined severe	1.69	1.09 to 2.62		–	–
AHI severity						0.5403
Mild/none (AHI <15)	–	–		Ref	–
Moderate (15≤AHI<30)	–	–		1.21	0.85 to 1.73
Severe (AHI ≥30)	–	–		1.11	0.82 to 1.50
CPAP use			0.0021			0.0068
Not regular	Ref	–		Ref	–
Regular	0.62	0.46 to 0.84		0.66	0.49 to 0.89
Framingham risk score (change per 10 points)	1.28	1.19 to 1.37	<0.0001	1.30	1.22 to 1.39	<0.0001

Addition of ethnicity and alcohol use did not meaningfully change the cluster model results (data not shown). Significant associations with primary outcome were also not found when continuous AHI (p>value 0.2276) or three severity categories (none (AHI<5, reference) versus mild (5≤AHI<15,p value of 0.4192), moderate (15≤AHI<30, p value of 0.1775) or severe (AHI≥30, p value of 0.2218)) were evaluated (data not shown).

^*Subjects without any component of the Framingham risk score excluded.

AHI, apnoea–hypopnoea index (events/hour of total sleep time); CPAP, continuous positive airway pressure; NREM, non-rapid eye movement; OSA, obstructive sleep apnoea; PLMS, periodic limb movements of sleep; REM, rapid eye movement.