TABLE 6

Approximated overall incident cases of airflow limitation/chronic obstructive pulmonary disease per 1000 person-years from previous studies on general populations using current Global Initiative for Chronic Obstructive Lung Disease (GOLD) and lower limit of normal (LLN) diagnostic criteria

First author [ref.]	At-risk subjects	Country	Mean age years	Current smokers %	Male/ female %/%	Incidence rate
						GOLD	LLN
Johannessen [6]	869	Norway	41	27	53/47	5.1	^#
Kojima [4]	17106	Japan	48	30	65/35	6.3	^#
Omori [9]	913	Japan	48	71	100/0	8.3	9.8
Lindberg [3]	963	Sweden	^¶	25	49/51	15.7	^#
Vestbo [8]	12 309	Denmark	52	61	^#	19.8⁺	^#
de Marco [10]	4425	Multinational	^§	^#	^#	2.88	1.85/2.41
Present study
LLN	892	Sweden	71	14	46/54		11.7
Fixed ratio	795	Sweden	70	13	45/55	28.2

Data are presented as n, unless otherwise stated. ^#: data not available; ^¶: data not available, age at study entry 46–77 years; ⁺: calculated from 5-year follow-up; ^§: data not available, age at study entry 20–44 years.