Table 2 Odds ratios (95% CIs) for participating in the follow-up and β–coefficients (95% CIs) for time to response (in days) as estimated from regression models adjusted for duration between baseline examination and follow-up invitation in years and day of the week the invitation were sent

 No-flyer

–

–

 Flyer

0.94

(0.80, 1.11)

1.71

(−1.01, 4.44)

 Male

–

–

 Female

1.49

(1.26, 1.75)

−0.80

(−3.59, 1.99)

 20–29

1.05

(0.76, 1.41)

3.85

(−1.77, 9.47)

 30–39

1.08

(0.79, 1.34)

1.62

(−3.16, 6.39)

 40–49

–

–

 50–59

1.39

(0.95, 1.55)

0.67

(−3.66, 5.00)

  ≥ 60

2.31

(1.50, 2.53)

−3.72

(−7.95, 0.52)

 German

–

–

 Other

0.33

(0.25, 0.44)

6.66

(0.36, 12.96)

 Level 1

–

–

 Level 2

1.15

(0.93, 1.42)

0.38

(−3.01, 3.78)

 0

–

–

 1

0.68

(0.55, 0.84)

7.80

(4.44, 11.16)

 2

0.59

(0.45, 0.77)

5.94

(1.27, 10.61)

  ≥ 3

0.39

(0.29, 0.53)

18.52

(12.47, 24.58)

 1

–

–

 2

0.84

(0.68, 1.03)

−0.51

(−4.02, 2.99)

  ≥ 3

0.67

(0.49, 0.92)

1.94

(−3.67, 7.56)

 No phone

–

–

 Phone

0.73

(0.57, 0.93)

5.21

(1.39, 9.03)

N