Table 5.

Explanatory variables for the variation in use of Index

	Univariate linear regression			Multiple linear regression
	Estimate	(95% CI)	P-value	Estimate	(95% CI)	P-value
Working experience	-0.011	(-0.018, -0.003)	0.004	-0.012	(-0.019, -0.004)	0.002
Rotation
With ground ambulance	-0.218	(-0.360, -0.076)	0.003	-0.213	(-0.348, -0.078)	0.002
With emergency room	0.054	(-0.057, 0.165)	0.337	0.033	(-0.074, 0.139)	0.545
With others	-0.093	(-0.283, 0.098)	0.339	-0.046	(-0.229, 0.137)	0.621
Repetition of use of Index
Regularly	0.214	(0.074, 0.354)	0.003	0.062	(-0.080, 0.205)	0.390
Irregularly	0.090	(-0.023, 0.203)	0.118	-0.002	(-0.116, 0.111)	0.969
Focus on use of Index
Clear focus	0.522	(0.312, 0.732)	<0.001	0.459	(0.240, 0.679)	<0.001
Some focus	0.293	(0.073, 0.512)	0.009	0.207	(-0.013, 0.426)	0.065

Exploration of possible explanations for the variation in use of Index, by univariate and multiple linear regression models.

Working experience = effect per year. P-value < 0.05 was regarded as statistically significant. Explained variation, R² = 0.234 for the multiple linear regression model.