Recruiting former melanoma patients via hospitals in comparison to office-based dermatologists in a register-based cohort study that required indirect contact

Table 4 Missing values in study questionnaire (Model 3)

Effect	OR	95% Confidence Limits		p-value
Physician characteristics
Location of hospital/practice (urban versus rural)	1.37	0.85	2.20	0.20
Median age of patients^a assigned to institution	0.99	0.97	1.02	0.72
Size of catchment area^a	1.01	0.10	1.02	0.10
Median tumor stage of all patients assigned to the physician	0.97	0.56	1.67	0.91
Number of contacts before participation	1.14	0.89	1.46	0.29
Recruitment proportion	0.67	0.15	2.91	0.59
Patient characteristics
Age of participant (years)	1.02	1.01	1.04	0.001
Sex (female versus male)	1.37	1.01	1.86	0.04
Participation after 2 contacts^b	1.25	0.90	1.73	0.19
Participation after ≥ 3 contacts^b	2.55	1.45	4.51	0.001
Time since diagnosis (years)	0.98	0.88	1.08	0.64
Place of residence (urban versus rural)	0.93	0.67	1.27	0.64
Social stratum (middle versus low)	0.66	0.48	0.91	0.01
Social stratum (high versus low)	0.69	0.46	1.03	0.07
Recruited by hospital versus office-based physician	0.50	0.20	1.26	0.14

^anumber of community codes the responding patients of each physician belong to
^bReference: Early responders (Participation after the first mail-out of study documents))

ISSN: 1471-2288