The effectiveness of a monetary incentive offer on survey response rates and response completeness in a longitudinal study

Table 2 Incentive and likelihood of returning a survey for study sample

	Returned survey				Likelihood of returning
	No (N, %)		Yes (N, %)		AOR^a	95% CI^b
	28,602	80.7	6819	19.3
Incentive group
Yes	26,787	80.6	6460	19.4	1.3	(1.1, 1.4)
No	1815	83.5	359	16.5	Ref	1
Sex
Female	11,023	80.2	2729	19.8	1.2	(1.1, 1.2)
Male	17,579	81.1	4090	18.9	Ref	1
Age at 9/11
< 18	596	86.1	96	13.9	1.4	(1.1, 1.9)
18–24	2500	85.6	421	14.4	0.9	(0.8, 0.9)
25–44	17,396	81.4	3968	18.6	Ref	1
45–64	7527	77.2	2223	22.9	1.2	(1.1, 1.3)
65+	518	82.9	107	17.1	0.8	(0.6, 1.0)
Race
Non-Hispanic white	16,756	78.2	4660	21.8	Ref	1
Non-Hispanic black	4671	85.1	816	14.9	0.8	(0.7, 0.9)
Hispanic	4019	83.6	786	16.4	0.9	(0.8, 1.0)
Asian	1713	81.8	331	16.2	0.8	(0.7, 0.9)
Multi-racial	584	83.9	112	16.1	0.8	(0.6, 0.9)
Other	859	88.3	114	11.7	0.7	(0.5, 0.9)
Total household Income in 2002, $
< 25,000	2635	85.6	442	14.4	Ref	1
25,000– < 50,000	6156	83.1	1249	16.9	1.1	(0.9, 1.2)
50,000– < 75,000	5472	79.1	1447	20.9	1.2	(1.1, 1.4)
75,000– < 150,000	8131	78.2	2266	21.8	1.2	(1.0, 1.3)
> =150,000	2636	78.5	723	21.5	1.1	(0.9, 1.3)
Education
High school and below	7186	84.2	1351	15.8	Ref	1
College	7305	80.9	1725	19.1	1.1	(1.1, 1.3)
Post-graduate	13,522	78.6	3683	21.4	1.3	(1.2, 1.4)
Reminder call
Yes	5528	63.0	3247	37.0	1.3	(1.2, 1.4)
No	23,074	86.6	3572	13.4	Ref	1
Door to door outreach
Yes	1995	92.1	171	7.9	0.3	(0.3, 0.4)
No	26,607	80.0	6648	20.0	Ref	1
Number of previous surveys completed
Three	8733	65.0	4702	35.0	7.7	(6.8, 8.6)
Two	9151	85.8	1515	14.2	2.8	(2.5, 3.1)
One	10,718	94.7	602	5.3	Ref	1

^aAOR: adjusted odds ratio and was adjusted for all factors listed in this table
^b95% CI: 95% confidence interval

ISSN: 1471-2288