| |
2 × 2 Factorial Design
|
|---|
| |
Overall
|
Pages
|
Notification
|
|---|
| | |
2
|
4
|
Letter
|
Postcard
|
|---|
|
Overall
|
363 (46.5)
|
169 (44.6)
|
194 (48.4)
|
179 (46.3)
|
184 (46.8)
|
|
Gender
| | | | | |
|
Female
|
212 (54.1)
|
105 (54.4)
|
107 (53.8)
|
108 (54.8)
|
104 (53.3)
|
|
Male
|
151 (38.9)
|
64 (34.4)
|
87 (43.1)
|
71 (37.4)
|
80 (40.4)
|
|
P value†
|
< 0.0001
|
0.007
|
0.03
|
0.0006
|
0.01
|
|
Race
| | | | | |
|
White
|
306 (52.6)
|
147 (50.5)
|
159 (54.6)
|
151 (52.6)
|
155 (52.5)
|
|
Non-white *
|
14 (24.14)
|
6 (22.2)
|
8 (25.8)
|
5 (15.6)
|
9 (34.6)
|
|
Unknown/Other
|
43 (30.7)
|
16 (26.2)
|
27 (34.2)
|
23 (33.8)
|
20 (27.8)
|
|
P value†
|
< 0.0001
|
< 0.0001
|
0.0002
|
< 0.0001
|
0.0003
|
|
Age
| | | | | |
|
25 - 29
|
35 (30.7)
|
12 (21.8)
|
23 (39.0)
|
12 (25.0)
|
23 (34.8)
|
|
30 - 39
|
81 (40.7)
|
32 (32.3)
|
49 (49.0)
|
42 (41.2)
|
39 (40.2)
|
|
40 - 49
|
107 (50.7)
|
51 (52.0)
|
56 (49.6)
|
57 (51.8)
|
50 (49.5)
|
|
50 - 59
|
103 (55.1)
|
56 (59.0)
|
47 (51.1)
|
50 (54.4)
|
53 (55.8)
|
|
60 - 65
|
37 (53.6)
|
18 (56.2)
|
19 (51.4)
|
18 (51.4)
|
19 (55.9)
|
|
P value†
|
0.0002
|
< 0.0001
|
0.63
|
0.008
|
0.04
|
- †P-values comparing response rates within condition from chi-square test or Fisher's exact test where appropriate.
- Note: In the factorial design, response rates did not differ significantly by survey length (p = 0.29) or by notification type (p = 0.87). Combining pages and notification into 4 separate groups, the p-value for the difference in response rate was 0.56 (results not shown).
- * "Non-white" includes: American Indian/Alaskan Native, Black or African American, Native Hawaiian/Pacific Islander, and Asian.
