Background:
The Swedish National Tobacco Quitline (SNTQ), which has both a proactive and a reactive service, has successfully provided tobacco cessation support since 1998. As there is a demand for an increase in national cessation support, and because the quitline works under funding constraints, it is crucial to identify the most clinically effective and cost-effective service. A randomized controlled trial was performed to compare the effectiveness of the high-intensity proactive service with the low-intensity reactive service at the SNTQ.

Methods:
Those who called the SNTQ for smoking or tobacco cessation from February 2009 to September 2010 were randomized to proactive service (even dates) and reactive service (odd dates). Data were collected through postal questionnaires at baseline and after 12 months. Those who replied to the baseline questionnaire constituted the study base. Outcome measures were self-reported point prevalence and 6-month continuous abstinence at the 12-month follow-up. Intention-to-treat (ITT) and responder-only analyses were performed.

Results:
The study base consisted of 586 persons, and 59% completed the 12-month follow-up. Neither ITT- nor responder-only analyses showed any differences in outcome between proactive and reactive service. Point prevalence was 27% and continuous abstinence was 21% in analyses treating non-responders as smokers, and 47% and 35%, respectively, in responder-only analyses.

Conclusions:
Reactive service may be used as the standard procedure to optimize resource utilization at the SNTQ. However, further research is needed to assess effectiveness in different subgroups of clients.

Trial registration:
ClinicalTrials.gov: NCT02085616