Table 1. Description of the study population (n = 548).

		N	%
Gender	Female	250	45.6
	Male	294	53.6	Female (n = 250)		Male (n = 294)
	Missing data	4	0.7	N	%	N	%
Age group	20 to 29 years	1	0.2	0	0	1	0.3
	30 to 39 years	32	5.8	25	10.0	7	2.4
	40 to 49 years	110	20.1	61	24.4	49	16.7
	50 to 59 years	250	45.6	122	48.8	128	43.5
	60 to 69 years	127	23.2	41	16.4	86	29.3
	70 to 79 years	22	4	1	0.4	21	7.1
	Older than 80 years	2	0.4	0	0.0	2	0.7
	Missing data	4	0.7	0	0.0	0	0.0
Type of practice	Single practice	274	50	120	48.0	154	52.4
	Group practice	245	44.7	114	45.6	128	43.5
	Medical centre	24	4.4	13	5.2	11	3.7
	Missing data	5	0.9	3	1.2	1	0.3
Place of practice	Rural municipality	194	35.4	80	32.0	113	38.4
	Small town	176	32.1	76	30.4	99	33.7
	Medium-sized town	74	13.5	38	15.2	35	11.9
	Metropolis	97	17.7	52	20.8	45	15.3
	Missing data	7	1.3	4	1.6	2	0.7
Employment status	Self-employed	472	86.1	193	77.2	279	94.9
	Employed	70	12.8	52	20.8	15	5.1
	Missing data	6	1.1	5	2.0	0	0.0
Volume of work	Full time	461	84.1	182	72.8	278	94.6
	Part time	80	14.6	66	26.4	12	4.1
	Missing data	7	1.3	2	0.8	4	1.4
Time in outpatient practice	Less than 10 years	114	20.8	74	29.6	39	13.3
	10 to 20 years	184	33.6	84	33.6	99	33.7
	20 to 30 years	156	28.5	74	29.6	81	27.6
	More than 30 years	90	16.4	15	6.0	75	25.5
	Missing data	4	0.7	3	1.2	0	0.0