Table 1.

Characteristics of the study population in Tromsø 6 (baseline)

	Working in a cold environment ≥ 25% of the time
	No, n = 2089		Yes, n = 258		t/χ2
	n	%	n	%	p
Agea	47.1	6.9	46.7	6.9	0.396
Sex
Female	1041	50	52	20
Male	1048	50	206	80	< 0.001
Number of moderate musculoskeletal complaints
0	1260	60.3	123	47.7
1	483	23.1	66	25.6
2	346	16.6	69	26.7	< 0.001
Education
Primary/secondary	154	7.4	61	23.6
Technical school	370	17.7	107	41.5
High school	196	9.4	37	14.3
College/university less than 4 years	559	26.7	41	15.9
College/university 4 years or more	810	38.8	12	4.7	< 0.001
Physical activity at work
Mostly sedentary work	1387	66.4	33	12.8
Work that requires a lot of walking	474	22.7	71	27.5
Work that requires a lot of walking and lifting	223	10.7	125	48.5
Heavy manual labour	5	0.2	29	11.2	< 0.001
Smoking status
Current	303	14.5	57	22.1
Former	745	35.7	101	39.1
Never	1041	49.8	100	38.8	0.001
Body mass index
Under and normal weight (< 25 kg/m2)	892	42.7	85	32.9
Overweight (≥ 25 and < 30 kg/m2)	886	42.4	131	50.8
Obese (≥ 30 kg/m2)	311	17.9	42	16.3	0.01
Self-reported health
Bad/very bad/neither good nor bad	231	11.1	40	15.5
Good	1193	57.1	171	66.3
Excellent	665	31.8	47	18.2	< 0.001

^aNumbers are mean and standard deviation for age