Table 3 Baseline characteristics and sickness absence in the intervention and control (usual care) groups in RCT 1 (occupational health intervention for the high risk group) and RCT 2 (telephone advice for the intermediate risk group)

	Group allocation
	Intermediate risk (IR)		High risk (HR)
	Control (IR-CG)	Intervention (IR-IG)	Control (HR-CG)	Intervention (HR-IG)
Baseline
n	269	268	209	209
Mean age (years)	42.9	42.8	46.8	46.7
Sex (female; %)	12	13	6	6
Blue-collar (%)	57	58	80	77
Sickness absence
None (% within group)	60	55	43	34
Mean (days)	4.6	5.9	17.9	19.7
Standard deviation	9.5	11.5	36.3	37.0
Median (days)	0	1	4	6
Upper quartile (days)	5	6	18	20
Maximum (days)	72	70	229	221
Sum (days)	1246	1581	3736	4115
Employment terminated during follow-up (%)	5.6	6.3	8.1	8.1
1 year follow-up
n	254	251	192	192
Sickness absence
None (% within group)	46	45	23	31
Mean (days)	6.9	7.0	29.9	19.3
Standard deviation	14.3	12.4	53.3	44.0
Median (days)	1	2	9	5
Upper quartile (days)	7	7	32	15
Maximum (days)	115	73	286	365
Sum (days)	1755	1751	5744	3702