International health policy survey in 11 countries: assessment of non-response bias in the Norwegian sample

Table 1 Logistic regression model: association between background variables and response

Variable	Odds ratio (OR)	OR 95% confidence interval	p
Male (vs. female)	1.02	0.78-1.33	0.90
Mean age	0.99	0.97-1.01	0.33
Mean years as GP	0.98	0.96-1.00	0.07
Group practice (vs solo practice)	1.62	1.12-2.33	0.01*
Specialist (vs not specialist)	2.04	1.51-2.76	<0.001***
Available positions on GP list (vs not available)	0.78	0.60-1.02	0.07
Health region
West (vs South/East)	0.78	0.56-1.10	0.15
Middle (vs South/East)	1.14	0.77-1.70	0.51
North (vs South/East)	0.69	0.44-1.10	0.09
Municipality centrality
Least central (vs most central)	1.61	1.10-2.44	0.03*
Little central (vs most central)	1.31	0.80-2.14	0.29
Quite central (vs most central)	1.02	0.75-1.40	0.91