Evidence of real-world effectiveness of a telephone quitline for smokers.

Background: Telephone services that offer smoking-cessation counseling (quitlines) have proliferated in recent years, encouraged by positive results of clinical trials. The question remains, however, whether those results can be translated into real-world effectiveness.

Methods: We embedded a randomized, controlled trial into the ongoing service of the California Smokers' Helpline. Callers were randomly assigned to a treatment group (1973 callers) or a control group (1309 callers). All participants received self-help materials. Those in the treatment group were assigned to receive up to seven counseling sessions; those in the control group could also receive counseling if they called back for it after randomization.

Results: Counseling was provided to 72.1 percent of those in the treatment group and 31.6 percent of those in the control group (mean, 3.0 sessions). The rates of abstinence for 1, 3, 6, and 12 months, according to an intention-to-treat analysis, were 23.7 percent, 17.9 percent, 12.8 percent, and 9.1 percent, respectively, for those in the treatment group and 16.5 percent, 12.1 percent, 8.6 percent, and 6.9 percent, respectively, for those in the control group (P<0.001). Analyses factoring out both the subgroup of control subjects who received counseling and the corresponding treatment subgroup indicate that counseling approximately doubled abstinence rates: rates of abstinence for 1, 3, 6, and 12 months were 20.7 percent, 15.9 percent, 11.7 percent, and 7.5 percent, respectively, in the remaining subjects in the treatment group and 9.6 percent, 6.7 percent, 5.2 percent, and 4.1 percent, respectively, in the remaining subjects in the control group (P<0.001). Therefore, the absolute difference in the rate of abstinence for 12 months between the remaining subjects in the treatment and control groups was 3.4 percent. The 12-month abstinence rates for those who made at least one attempt to quit were 23.3 percent in the treatment group and 18.4 percent in the control group (P<0.001).

Conclusions: A telephone counseling protocol for smoking cessation, previously proven efficacious, was effective when translated to a real-world setting. Its success supports Public Health Service guidelines calling for greater availability of quitlines.