Table 1.
Results of random allocation of voucher or not on response rate
| Voucher | No voucher | |
| Questionnaire returned | 156 (42.3%) | 108 (30.6%) |
| Questionnaire not returned | 213 | 245 |
| Total | 369 | 353 |
Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.