Table 1.

Descriptive characteristics of the study participants at baseline and follow-up

Variable	Categories	Baseline (2015)		Follow-up (2021)
		N	%	N	%
Age group (years)	18–31	476	9.5	217	5.3
	32–44	872	17.4	670	16.3
	45–57	1603	32.0	1271	30.9
	58–70	2066	41.2	1953	47.5
Body mass index (kg/m2)	BMI < 20	190	3.9	183	3.8
	20 ≤ BMI < 25	2063	41.8	1885	38.7
	25 ≤ BMI < 30	1909	38.7	1933	39.7
	BMI > 30	769	15.6	864	17.8
Tobacco habits	Daily smoking	289	5.8	190	3.8
	Daily snuff use	665	13.4	686	13.8
Work status	Not workinga	1064	21.7	1907	38.3
	Working	3843	78.3	3078	61.7
Occupational cold exposure	None (NRS 1)	2857	59.2	2190	51.0
	Any (NRS > 1)b	1969	40.8	2105	49.0
Leisure-time cold exposure	Low (NRS ≤ 5)	2442	49.5	1660	33.5
	High (NRS > 5)b	2487	50.5	3295	66.5
Airway symptomsc	Wheeze	936	18.7	837	16.7
	Long-standing cough	1086	21.7	772	15.4
	Productive cough	1000	19.9	942	18.8

BMI body mass index, NRS numerical rating scale

^aPensioners, students, unemployed, and those on sick or parental leave

^bDichotomized based the 50th percentile

^cAffected by item non-response and presented as absolute percentages