The most frequently employed interventions for improving adherence reviewed were NRT, antidepressant therapy, pharmacist intervention, psychosocial/behavioural support and counselling, and diet counselling (low-calorie diet) (see also Table 9). Adjunctive psychosocial treatment or behavioural advice has been successfully used to support smoking cessation programmes (25).

Although Alterman et al. showed that patients receiving more intense adjunctive psychosocial or medical treatment were more adherent to treatment with patches (25), overall, the data reviewed suggested that minimal behavioural support also results in similar or higher adherence rates, at least for some types of smoker. Minimal behavioural support might offer a cost-effective way to implement first-line smoking cessation programmes at a population level. More controlled studies including cost-effectiveness analysis are needed to clarify this issue.

The monitoring of therapeutic drug levels, NRT and/or antidepressant may also be useful. This feedback might be used to identify poorly adherent patients for whom more intensive adherence-enhancing interventions would be helpful (46).

Intensive anti-smoking campaigns, such as the "Truth Denormalization Ads" might be extremely useful, especially among teenagers, as they change the social attitude towards tobacco smoking.

Table 9 Factors affecting adherence to smoking cessation therapy and interventions for improving it, listed by the five dimensions and the interventions used to improve adherence

CO, Carbon monoxide; NRT, nicotine replacement therapy; (+) factors having a positive effect on adherence; (-) factors having a negative effect on adherence.