TABLE 4

Results from Cox regression models^# analysing time to first exacerbation for subgroups of participants

	Time to first exacerbation for participants where treatment was guided by F_ENO compared to standard care		Interaction p-value
	HR (95% CI)	p-value
LTRA treatment
Yes	0.76 (0.57–0.99)	0.048	0.049
No	1.26 (0.82–1.90)	0.292	0.049
ICS dose
≤400 μg BUD	0.76 (0.52–1.12)	0.166	0.393
>400 μg BUD	0.94 (0.71–1.25)	0.667	0.393
Obese
Yes	0.96 (0.74–1.25)	0.787	0.456
No	0.78 (0.48–1.27)	0.321	0.456
Atopic
Yes	0.61 (0.29–1.31)	0.207	0.347
No	0.90 (0.70–1.16)	0.412	0.347
Ethnic group
White	1.24 (0.76–2.02)	0.391	0.268
Non-white	0.90 (0.67–1.20)	0.469	0.268

F_ENO: exhaled nitric oxide fraction; HR: hazard ratio; LTRA: leukotriene receptor antagonist; ICS: inhaled corticosteroids; BUD: budesonide equivalent. ^#: these models are fitted as time = subgroup + treatment group + subgroup * treatment + age + study ID + baseline ICS. Baseline ICS was not included in the model where outcomes between ICS subgroups were analysed.