TABLE 3.

SUMMARY OF CROSS-SECTIONAL STUDIES THAT COMPARED CLINICAL CHARACTERISTICS IN SUBJECTS WITH CHRONIC OBSTRUCTIVE PULMONARY DISEASE WITH AND WITHOUT CHRONIC COUGH AND SPUTUM PRODUCTION

				Current Smokers		Exacerbations/Patient/yr		Dyspnea MMRC Scale		HRQoL
Study	Population	n	Chronic Cough and/or Sputum	Cough + Sputum	No Cough + Sputum	Cough + Sputum	No Cough + Sputum	Cough + Sputum	No Cough + Sputum	Cough + Sputum	No Cough + Sputum
Agusti et al. (20)	Clinic based (multinational)	2,161	34.6	GOLD 2: 52*GOLD 3: 46*GOLD 4: 37*	GOLD 2: 3†GOLD 3: 3GOLD 4: 21	GOLD 2: 0.6 ± 1.1GOLD 3: 1.0 ± 1.2GOLD 4: 1.2 ± 1.6	GOLD 2: 0.7 ± 1.0GOLD 3: 1.0 ± 1.4GOLD 4: 1.2 ± 1.3	GOLD 2: 1.5 ± 1.0*GOLD 3: 1.8 ± 1.0GOLD 4: 2.4 ± 1.0	GOLD 2: 1.3 ± 1.0GOLD 3: 1.8 ± 1.1GOLD 4: 2.3 ± 1.0	SGRQ-CGOLD 2: 50.3 ± 18.8*GOLD 3: 58.8 ± 17.6*GOLD 4: 65.0 ± 16.5*	SGRQ-CGOLD 2: 38.9 ± 20.5GOLD 3: 51.2 ± 18.2GOLD 4: 59.4 ± 15.2
Burgel et al. (4)	Clinic based (France)	433	74.1	28*	18	2.2 ± 2.2*	1.0 ± 1.2	N/A	N/A	N/A	N/A
Kim et al. (6)	Clinic based (USA)	1,061	27.3	48*	27	1.2 ± 1.6*	0.6 ± 1.1	2 (2–4)*	2 (1–3)	SGRQ: 62.5 ± 19.0*	SGRQ 38.0 ± 22.4
de Oca et al. (21)	Population based (Latin America)	759	14.4†	47*	32	5.42	2.66	Present: 76*	Present: 47	SF-12 physical score44.6 ± 1.0*	SF-12 physical score49.5 ± 0.4
Lu et al. (25)	Population based (China)	1,668	30.0	48*	37	N/A	N/A	MMRC > 2: 64*	MMRC > 2: 29	N/A	N/A

Definition of abbreviations: GOLD = Global Initiative for Chronic Obstructive Lung Disease; HRQoL = health-related quality of life; MMRC = Modified Medical Research Council; N/A: not applicable; SF-12: Short Form-12 questionnaire; SGRQ = St. George’s Respiratory Questionnaire; SGRQ-C = COPD version of the SGRQ.

Data presented as %, mean ± SD, or median (interquartile range), unless otherwise specified. Reproduced by permission from Reference 122.

^*P < 0.05.

^†Phlegm most days, at least 3 mo/yr for ≥2 yr.