Mixing modes in a population-based interview survey: comparison of a sequential and a concurrent mixed-mode design for public health research

Table 6 Costs for the concurrent and the sequential mixed-mode designs in GEDA 2.0^a

	Concurrent mixed-mode design					Sequential mixed-mode design
	Number of mailings	Cost factors				Number of mailings	Cost factors
	Number of mailings	Small letter	Large letter	Printed questionnaire	Data entry	Number of mailings	Small letter	Large letter	Printed questionnaire	Data entry
1st contact	3360		3360	3360		3360	3360
2nd contact	2786	2786				2991		2991	2991
3rd contact	2487	2487				2677	2677
Total letters	8633	5273	3360	3360		9028	6037	2991	2991
Valid questionnaires SAQ-Paper	482				482	264				264
Valid questionnaires SAQ-Web	124					290
Valid questionnaires (without CATI)	606					554
Cost analysis
Costs per unit		0.70 €	2.20 €	3.00 €	9 min		0.70 €	2.20 €	3.00 €	9 min
Postage and printing costs in €		3691.10	7392.00	10 080.00			4225.90	6580.20	8973.00
Postage for received question. in €			1060.40					580.80
Total postage and printing costs in €				22 223.50				20 359.90
Total costs in working minutes					4338					2376
Total postage and printing costs per valid questionnaire in €				36.67					36.75
Total working time needed per valid questionnaire (in min)					7.2					4.3

^aExcluding overhead costs and working time for supervision, data cleaning, and homogenization. CATI computer-assisted telephone interviewing

ISSN: 2049-3258