Table 4– The risk of exacerbations, hospital admissions and death among participants with chronic obstructive pulmonary disease according to night-time dyspnoea, derived from a Cox regression model with age as the underlying time scale

	Univariate model adjusted for age and sex	Multivariate model adjusted for age, sex and GOLD 1–4^#	Multivariate model adjusted for age, sex and GOLD A–D^¶
Exacerbations⁺
No night-time dyspnoea	1 (ref.)	1 (ref.)	1 (ref.)
Night-time dyspnoea	2.28 (1.74–3.00)	1.79 (1.36–2.36)	1.39 (1.05–1.84)
Admissions^§
No night-time dyspnoea	1 (ref.)	1 (ref.)	1 (ref.)
Night-time dyspnoea	3.18 (2.30–4.39)	2.07 (1.49–2.87)	1.30 (0.93–1.81)
All-cause mortality^ƒ
No night-time dyspnoea	1 (ref.)	1 (ref.)	1 (ref.)
Night-time dyspnoea	1.65 (1.19–2.27)	1.37 (0.99–1.89)	1.03 (0.74–1.44)

Data are presented as hazard ratio (95% confidence interval). The hazard ratio is considered statistically significant if the confidence interval does not include 1 (bold). GOLD: Global Initiative for Chronic Obstructive Lung Disease. ^#: spirometry-based classification of COPD based on forced expiratory volume in 1 s (FEV₁) as a percentage of the predicted value; ^¶: clinical classification according to FEV₁ % pred, symptom burden and frequency of exacerbations; ⁺: n=687; ^§: n=359; ^ƒ: n=591.