Table 1

Baseline sociodemographic and psychosocial characteristics in the study population of persons with occasional neck, shoulder and/or arm pain at baseline (n=6979)

	Low strain (n=5358)		Active jobs (n=1003)		Passive jobs (n=518)		High strain (n=100)
	N	%	N	%	n	%	n	%
Age (years)
18–44	2981	56	613	61	348	67	64	64
45–61	2377	44	390	39	170	33	36	36
Sex
Men	2145	40	384	38	158	30	32	32
Women	3213	60	619	62	360	70	68	68
Country of birth
Sweden	4600	86	899	90	404	78	83	83
Elsewhere	758	14	104	10	114	22	17	17
Socioeconomic class*
Unskilled and semiskilled workers	656	13	64	7	162	34	33	35
Skilled workers	611	12	62	6	76	16	11	11
Assistant non-manual employees	778	15	107	11	108	23	12	12
Intermediate non-manual employees	1358	26	321	33	90	19	24	24
Employed/self-employed professionals, civil servants and executives	1265	24	331	34	29	6	10	10
Self-employed (other than professionals)	492	10	84	9	8	2	4	4
Sleep disturbances
None	3861	72	601	60	326	63	54	54
Mild/severe	1497	28	402	40	192	37	46	46
Workload
Sedentary	2207	41	464	46	192	37	36	36
Light	1572	29	272	27	119	23	18	18
Moderately heavy	1156	22	192	19	149	29	18	18
Heavy	409	8	74	7	56	11	27	27
Low support at work from superiors (yes)	458	18	321	32	183	35	69	69
Low support at work from colleagues (yes)	622	9	150	15	71	14	20	20
Economic stress (yes)†	367	7	77	8	73	14	16	16
Household work
>5 h/week	2135	40	456	45	183	36	39	39
Comorbidity LBP
Yes, 2 days or more often during previous 6 months	3318	62	648	65	345	67	67	67
Smoking habits (daily)	702	13	121	12	79	15	13	13
Alcohol (yes, sometime during the past 12 months)	4945	93	949	95	458	89	87	87
Leisure physical activity level
Sedentary <2 h/week	477	9	102	10	83	16	18	18
Active ≥2 h/week	4877	91	895	89	432	84	81	81

*Socioeconomic class: based on occupation and education.
†Economic stress (“Did it happen that during the past 12 months you ran out of salary/money and had to borrow from relatives and friends in order to pay for food or rent?”). LBP, low back pain.