Table 2

Distribution of measured lung function values by characteristics assessed at the first examination

	FEV₁						FVC
	First examination (1999–2003) (mL)		Second examination (2010–2014) (mL)		Difference between examinations* (mL/year)		First examination (1999–2003) (mL)		Second examination (2010–2014) (mL)		Differences between examinations* (mL/year)
	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD	Mean	SD
Whole population	3510	797	3028	756	−43.0	26.4	4377	984	3992	953	−34.3	34.1
Sex
Male	4047	694	3519	679	−47.5	29.9	5088	804	4660	807	−38.9	38.2
Female	3000	496	2566	486	−38.8	21.9	3703	582	3366	583	−30.1	29.2
Smoking status
Never	3513	814	3058	772	−40.4	25.5	4347	1011	3984	980	−32.3	33.5
Ex-smoker	3533	803	3047	753	−43.6	26.4	4432	980	4035	956	−36.3	34.7
Current smoker	3480	772	2951	724	−46.9	27.9	4364	952	3954	900	−36.8	35.6
Diseases
None	3612	781	3148	748	−41.5	24.7	4435	978	4089	955	−30.7	33.4
Asthma	3207	799	2761	772	−39.0	28.9	4189	1000	3803	976	−34.4	35.9
COPD†	2853	768	2478	784	−33.4	33.5	4371	1093	3883	1098	−42.9	43.2
Comorbidity‡	3315	783	2824	754	−43.1	26.3	4170	951	3750	947	−38.0	32.9

*Lung function at the second examination (2010–2014) minus that at the first examination (1999–2003), divided by time between the examinations. The means of the lung function parameters were significantly different across the two examinations for all lung function parameters (Student’s t-test for paired data, all P values <0.001).
†Defined as FEV₁/FVC less than the lower limit of normal predicted using the Global Lung Initiative equations.29
‡Report of either arthritis, hypertension, heart disease, diabetes, cancer and stroke. Only available for 19 out of 25 participating centres.