Table 6

Effect of respondent characteristics and initial bids on time-tradeoff amounts

Variable
Type of variable
Impact on TTO
95 % CI
P value

Independent variables:




     TTO amounts1




Dependent variables:




Baseline2
Constant
0.5545
(0.2402, 1.2798)
0.1617
Age3




     18–34
Binary
1.0385
(0.4904, 2.1994)
0.9200
     35–49
Binary
1.1698
(0.6299, 2.1723)
0.6137
     50–64
Binary
1.5448
(0.7921, 3.0129)
0.1959
Female
Binary
0.8629
(0.5926, 1.2565)
0.4342
Education: Some college or less
Binary
1.1579
(0.7537, 1.7789)
0.4966
Not married
Binary
0.9204
(0.5815, 1.4569)
0.7188
Health (Worse than average)
Binary
1.1043
(0.7343, 1.6606)
0.6279
No children under 18 in household
Binary
0.7663
(0.4541, 1.2930)
0.3114
Version (initial bid)4




     1 (1 week)
4 binary variables, one for each initial bid
2.8454
(1.7138, 4.7242)
<0.0001
     2 (1 month)

1.3331
(0.7943, 2.2374)
0.2694
     3 (2 weeks)

1.4705
(0.8741, 2.4739)
0.1415





Income (less than 3X poverty level)
Binary
1.0092
(0.5398, 1.8870)
0.9766
Number of disease experienced: None
Binary (0 v. 1 or more)
1.2406
(0.7396, 1.9394)
0.3370

1 Independent variables included for each respondent were uncomplicated influenza in a 1-year-old, uncomplicated influenza in a 14 year-old, and anaphylaxis or Guillain-Barré syndrome. R-squared = 0.2194.

2 Baseline refers to a person over 65 years of age, male, college graduate, married, good health, with income three times or greater than poverty level, children under 18 living in the household, familiar with at least one of the conditions in the survey, and responding to survey version 4 (initial bid of 6 months).

3 Compared to 65 and over.

4 Compared to version 4 (initial bid of 6 months).

Prosser et al. Health and Quality of Life Outcomes 2005 3:18   doi:10.1186/1477-7525-3-18