Female smokers beyond the perimenopausal period are at increased risk of chronic obstructive pulmonary disease: a systematic review and meta-analysis

Table 1 Characteristics of studies included in meta-analyses*

Source	Project name	Sample size	Women (%)	Average age at baseline (year)	Duration of follow up (year)
Viegi et al,²² 2001	Po River Delta Epidemiologic Study, North Italy	1774	51	32	8
Chinn et al,¹² 2005	European Community Respiratory Health Survey II, 27 centers, 26 were in western Europe and one was in the USA	6654	51	34	9
Rijcken et al,¹³ 1995	Vlagtwedde-Vlaardingen study in the Netherlands	1619	43	39	25
Jedrychowski et al,¹⁴ 1986	Cracow Study in Cracow, Poland	1364	64	40	13
James et al,¹⁵ 2005	Busselton Health Study in Busselton, Western Australia	9317	51	42	29
Tashkin et al,¹⁶ 1984	UCLA Population Studies in Los Angeles County, USA	2401	54	46	5
Sherrill et al,¹⁷ 1996	Tucson Epidemiology Study of Obstructive Lung Disease in Tucson, Arizona, USA	477	41	48	8
Connett et al,²³ 2003^†	Lung Health Study, 10 centres, nine in the USA, one in Canada	5346	37	48	5
Xu et al,¹⁸ 1992	Six Cities Study in the USA	12 080	55	49	6
Vestbo et al,¹⁹ 1996	Copenhagen City Heart Study, Denmark	9435	57	53	5
Griffith et al,²⁰ 2001	Cardiovascular Health Study in the USA	5242	57	73	7

Symbols: *: Order in table: average age at baseline; †: The participants were smokers with mild-to-moderate COPD.