Table 1. Characteristics of the Participants.

	Britain			Japan			Finland
	Men (n=5122) %	Women (n=2218) %	P value	Men (n=1638) %	Women (n=659) %	P value	Men (n=1649) %	Women (n=6515) %	P value
Mean age	48.6(5.57)	49.7(5.78)	<0.001	50.4(5.49)	49.9(5.59)	0.022	50.0(6.61)	49.1(6.59)	<0.001
Age groups
40-49	59.9	50.8		45.5	51.3		38.3	43.2
50-60	40.1	49.2	<0.001	54.5	48.7	0.013	61.7	56.8	<0.001
Grades
Grade 1	48.3	16.5		24.2	3.2		43.6	27.6
Grade 2	45.1	45.0		31.2	24.4		19.4	19.1
Grade 3	6.6	38.5	<0.001	44.5	72.4	<0.001	10.1	42.1
Grade 4	–	–		–	–		26.9	11.2	<0.001
Control
Low	25.7	49.4		30.8	39.5		28.3	27.5
Intermediate	31.9	27.8		34.6	37.0		31.5	33.0
High	42.5	22.8	<0.001	34.6	23.5	<0.001	40.2	39.5	<0.497
Demand
Low	31.2	42.8		37.8	24.6		38.0	31.1
Intermediate	33.8	30.5		40.6	39.8		25.8	25.6
High	35.1	26.7	<0.001	21.6	35.7	<0.001	36.3	43.3	<0.001
Work hours*
<7 hours /day	2.1	5.8		10.0	5.2		7.3	10.5
7-9 hours /day	69.7	78.7		67.6	60.7		71.3	76.3
9-11 hours / day	22.3	13.3		16.2	26.4		17.8	11.6
11 <hours /day	5.9	2.2	<0.001	6.1	7.7	<0.001	3.6	1.6	<0.001
Mean PCS	53.2(5.91)	50.6(8.05)	<0.001	49.5(6.20)	47.3(7.05)	<0.001	50.5(7.47)	48.9(8.56)	<0.001
Mean MCS	51.2(8.31)	50.1(9.18)	<0.001	47.4(9.80)	44.1(10.9)	<0.001	51.5(10.0)	51.6(9.81)	0.792

Abbreviations: In the British population, Grade 1: unified grade 1-6; Grade 2: unified grade 7 and executive officers; Grade 3: clerical officers. In the Japanese population, Grade 1: senior administrative officers; Grade 2: administrative officers; Grade 3: civil servants with no administrative title. In the Finnish population, Grade 1: managers; Grade 2: professionals; Grade 3: clerical officers; Grade 4: manual workers. PCS: physical component summary scale; MCS: mental component summary scale. Data on age, PCS and MCS are expressed as mean (standard deviation).

^*In the Finnish population, work hours was categorised as less than 30 hours /week, 30-40 hours /week, 41-50 hours /week, and more than 50 hours / week.