Table 4.

Operator characteristics

		N	%
Sex	Female	178	65
	Male	85	32
	Missing	9	3
		272	100
Education	Ambulance worker	50	18
	Registered nurse	230	85
	Ambulance worker and nurse	16	69
	Other	11	4
	Further education	86	32
Work rotation	None	73	27
	With emergency room	116	43
	With ambulance	44	16
	Other	19	7
	Missing	20	7
		272	100
Work experience	≤ 1 year	27	10
	>1 ≤ 5 years	95	35
	>5 ≤ 10 years	60	22
	> 10 years	78	29
	Missing	12	4
		272	100
Training in use of Index	Formal training from the start	234	86
	Formal training eventually	16	6
	Taught by colleagues	8	3
	None	2	1
	Missing	12	4
		272	100
Repetition of use of Index	Regularly	51	19
	Irregularly	129	47
	None	71	26
	Missing	21	8
		272	100

Background information on the operators’ (N = 272) educational and work experience, together with experienced initial training in use of Index and later repetitions.