The allocation of intervention conditions to regions was not by random assignment, but on the basis of practical and ethical considera- tions. Although the evaluation phases were designed primarily as a rigorous assessment of the eVectiveness of the interventions, the fact could not be ignored that the interventions might have a substantial positive eVect on smoking behaviour in the regions chosen. We therefore felt that, given the considerable health budget involved, there was an imperative that the study media intervention should take place in regions of England with the highest smoking prevalence, where there was the greatest need to reduce smoking. Hence, Granada, Tyne Tees and Yorkshire were allocated to media intervention. Central was chosen as the control region since it was geographically and also demographically close to the preselected media intervention regions. Of all the areas available within the media intervention regions for a local tobacco control network, West Yorkshire was chosen because their pre-existing anti-smoking activities seemed to have the greatest potential to develop a vigorous local activity network in a relatively short space of time. The lack of ran- domisation of regions to interventions was not considered to be a significant handicap for the study, since: (1) the number of regions was small and randomisation could not possibly equalise diVerences between regions; and (2) we planned to adjust the comparisons of outcome between the interventions for any potentially confounding background charac- teristics (see below).