Table 1.
Demographics of respondents and nonrespondents. IQR: interquartile range.
| Characteristic | Responders (n=7434) | Nonresponders (n=370,191) | P valuea | |
| Age (years), n | 7419 | 321,886 | <.001b | |
|
|
Mean (SD) | 54 (12) | 48 (14) |
|
|
|
Median (IQR) | 54 (46-62) | 48 (38-58) |
|
| Sex, n (%) |
|
|
.61 | |
|
|
Female | 5290 (71.16) | 232,260 (71.60) |
|
|
|
Male | 2059 (27.70) | 92,111 (28.39) |
|
|
|
Prefer to skip | 0 | 21 (<0.01) |
|
| Race, n (%) |
|
|
<.001 | |
|
|
White | 6106 (86.59) | 163,857 (80.65) |
|
|
|
Black | 302 (4.28) | 9996 (4.92) |
|
|
|
Mixed race | 291 (4.13) | 7591 (3.74) |
|
|
|
Asian | 99 (1.40) | 8653 (4.26) |
|
|
|
Native American | 90 (1.28) | 2175 (1.07) |
|
|
|
Hawaiian | 6 (<0.01) | 514 (0.25) |
|
|
|
Prefer to skip | 158 (2.24) | 10,397 (5.12) |
|
| Education, n (%) |
|
|
<.001 | |
|
|
High school grad or less | 898 (14.90) | 18,784 (19.51) |
|
|
|
Some college | 2365 (39.25) | 36,172 (37.58) |
|
|
|
College graduate | 1565 (25.97) | 22,881 (23.77) |
|
|
|
Post graduate | 1132 (18.79) | 15,344 (15.94) |
|
|
|
Prefer to skip | 66 (1.10) | 3080 (3.20) |
|
| Insurance, n (%) |
|
|
<.001 | |
|
|
Medicare | 1696 (28.03) | 15,518 (16.27) |
|
|
|
Employer | 1802 (29.78) | 31,994 (33.54) |
|
|
|
Medicaid | 589 (9.73) | 8412 (8.82) |
|
|
|
National | 574 (9.49) | 10,691 (11.21) |
|
|
|
Direct | 514 (8.49) | 8066 (8.46) |
|
|
|
Veterans Affairs | 153 (2.53) | 1890 (1.98) |
|
|
|
Military | 115 (1.90) | 1729 (1.81) |
|
|
|
Indian Health Service | 2 (<0.01) | 108 (0.11) |
|
|
|
Other | 97 (1.60) | 1949 (2.04) |
|
|
|
None | 351 (5.80) | 8580 (8.99) |
|
|
|
Prefer to skip | 158 (2.61) | 6451 (6.76) |
|
aP values from t test for age and chi-square test for categorical variables.
bSatterthwaite method reported due to unequal variances.