Fig. 3.
Mean duration of continuous cocaine abstinence over the 24-week duration of treatment and in the first and second halfs. “Voucher” indicates CRA + Voucher condition and “No Voucher” indicates CRA-only condition. (From Higgins et al., 1994)
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.