Enhancing the impact of groups: an evaluation of two group formats for smokers.

The effects of two different group formats constituting part of an otherwise identical smoking cessation programme were evaluated. Each group format was in use for one full calendar year. One hundred and thirty-two smokers were treated in 14 'therapist-oriented' (T-O) groups run in traditional didactic style and 138 in 14 'group-oriented' (G-O) groups, where the primary emphasis was on group resources (group support, group pressure and spontaneous modelling of coping responses). G-O groups were significantly more successful. The two types of groups did not differ in the number of clients who succeeded in stopping smoking just after the first meeting, i.e. before the difference in group formats could have any impact; but in the G-O groups more of those who failed initially persisted in trying and succeeded later in the course. Independently of the format, larger groups were more successful and in addition there was significant variation between single groups regardless of both format and size. Group processes seem to play an important role in smoking cessation and the way in which a group is structured can affect outcome.