Table 3

Factors associated with increased odds of non-response

	Univariable analysis		Individual-level factors and RE of unit model*		Models adjusted for the individual-level effects and RE of unit†
	OR (95% CI)	p Value	aOR (95% CI)	p Value	aOR (95% CI)	p Value
Individual-level effects	Non-responders (n=3541)		Responders (n=20 939)
Gender
Female	Ref	<0.001	Ref	<0.001	–
Male	1.8 (1.7 to 2)		1.9 (1.8 to 2.1)
Age
≥45	Ref	<0.001	Ref	<0.001	–
<45	1.6 (1.5 to 1.7)		1.5 (1.4 to 1.6)
Place of residence
<500 000	Ref	<0.001	Ref	<0.001	–
≥500 000	4.1 (3.7 to 4.6)		1.6 (1.4 to 1.8)
PHCU-level effects	PHCUs (n=44)
Unit size
<2500	Ref	<0.001	–		Ref	<0.001
2500–9999	4.3 (3.6 to 5.1)				3.6 (2.8 to 4.4)
≥10 000	2.3 (1.9 to 2.8)				2.3 (1.8 to 2.9)
Unit ownership
Public	Ref	<0.001	–		Ref	0.009
Private	1.6 (1.5 to 1.8)				1.2 (1 to 1.3)
Experience in running public health programmes in the past
No	Ref	0.101	–		Ref	0.005
Yes	0.9 (0.8 to 1)		–		0.8 (0.7 to 0.9)
Local promotion programme
No	Ref	0.001			Ref	<0.001
Yes	1.2 (1.1 to 1.2)		–		1.4 (1.3 to 1.6)
Mode of invitation
Passive-active	Ref	<0.001	–		Ref	<0.001
Active-very active	0.5 (0.5 to 0.5)				0.6 (0.5 to 0.6)
Number of personnel involved in the project
1–5	Ref	0.751	–		Ref	<0.001
>5	1 (0.9 to 1.1)				1.4 (1.2 to 1.6)
Working hours devoted to the project (hours/week)
<10	Ref	<0.001	–		Ref	<0.001
≥10	0.7 (0.7 to 0.8)				0.7 (0.7 to 0.8)
Working hours per patient (hour)
<0.5	Ref	<0.001			Ref	0.0921
0.5–<1	0.9 (0.8 to 0.97)				0.7 (0.2 to 2.8)
≥1	0.6 (0.5 to 0.7)				0.1 (0.02 to 0.8)

*This model included effects of gender, age, place of residence and the random effect for the unit.
†Each of the aOR for a unit-level covariate corresponds to a separate model with effects of gender, age, place of residence, the random effect of the unit and a fixed effect of this unit-level covariate.
aOR, adjusted OR; PHCU, primary healthcare unit; RE, random effect.