Methods
We searched 35 electronic databases from inception to
July 2002 and the internet using several search
engines. The bibliographies of retrieved references
were scanned for further relevant publications. The
authors of abstracts in conference proceedings were
contacted for further information.
Eligible for inclusion were randomised controlled
trials evaluating the effectiveness of stage based
interventions in influencing smoking behaviour—such
as actual behaviour change or movement through different
stages. No restrictions were applied to participants
other than they had to be smokers, and there
were no restrictions on language or publication date.
Two reviewers independently assessed the titles and
abstracts and then assessed relevant papers against the
predetermined selection criteria. Data were extracted
by one reviewer into structured summary tables and
checked by a second reviewer. Extracted data included
smoking behaviour, movement through stages, adverse
effects, and cost effectiveness.
Each included trial was assessed for methodological
quality and the quality of the implementation of the