The use of the changing criterion design in achieving controlled smoking in a heavy smoker: a controlled case study.

This study describes the use of the changing criterion design for decreasing smoking rate. Evidence is provided which demonstrates that boundaries exist within which a well-established, high frequency baseline smoking rate (82 cigarettes per day) can be successfully modified and maintained at the rate of 5 cigarettes per day over a 20-month follow-up period. It is concluded that controlled smoking can be a viable alternative for individuals unable or unwilling to quit; further, this goal can be achieved through the changing criterion design, which allows for the demonstration of experimental control in a situation requiring minimal therapist contact.