Comparison of response rates and cost-effectiveness for a community-based survey: postal, internet and telephone modes with generic or personalised recruitment approaches

Table 1 Response rates for the greywater use survey

Type of approach	Number of approaches	Number of responses	Crude response rate (%)	Adjusted number of approaches	Adjusted number of responses	Adjusted response rate (%) and (95% CI)
Postal survey personalised	5,500	511	9.3	5,500	575^*	10.5 (9.7-11.3)
Postal survey generic	4,000	266	6.7	4,000	299^*	7.5 (6.7-8.3)
Internet survey personalised	10,000	289	2.9	6,210^**	289	4.7 (4.2-5.2)
Internet survey generic	7,000	101	1.4	4,515^***	101	2.2 (1.8-2.6)
Telephone survey personalised	1,000	273	27.3	903^****	273	30.2 (27.2-33.2)
Total	34,500	1621	4.7	25,384	1,621	6.4 (6.1-6.7)

^* Adjusted by distribution of 97 postal surveys with unknown postcode to personalised (n = 64) or generic modes (n = 33) as per survey response rates for known postcodes.
^** 62.1% of households in the personalised internet survey area had internet access.
^*** 64.5% of households in the generic internet survey area had internet access.
^**** Crude response rate calculated for 1,000 telephone numbers (minimum quantity for data file purchase), adjusted rate is for 903 telephone numbers with at least one contact attempt made. Of 866 households contacted, 352 refused, 148 were missed call backs, 93 had language difficulties. There were 37 numbers with technical difficulties.

ISSN: 1471-2288