Can anti-smoking television advertising affect smoking behaviour? controlled trial of the Health Education Authority for England's anti-smoking TV campaign

Abstract

Objectives: To evaluate the effectiveness of the Health Education Authority for England's anti-smoking television advertising campaign in motivating smokers to give up and preventing relapse in those who had already given up.

Design: A prospective, controlled trial was conducted in four TV regions in central and northern England. One region received no intervention (controls), two regions received TV anti-smoking advertising (TV media), and one region received TV anti-smoking advertising plus locally organised anti-tobacco campaigning (TV media + LTCN). The TV advertisements were screened in two phases over 18 months; during the first phase the intensity of the advertising was varied between TV regions. 5468 men and women (2997 smokers, 2471 ex-smokers) were selected by two stage random sampling and interviewed before the intervention, of whom 3610 were re-interviewed six months later, after the first phase of the campaign. Only those interviewed at six months were followed to the main end point at 18 months when 2381 subjects were re-interviewed.

Main outcome measures: Self reports of cigarette smoking at the 18 month follow up were compared between the three levels of intervention. Odds ratios for intervention effects were adjusted for pre-intervention predictors of outcome and pooled for smokers and ex-smokers using meta-analytic methods.

Results: After 18 months, 9. 8% of successfully re-interviewed smokers had stopped and 4.3% of ex-smokers had relapsed. The pooled adjusted odds ratio for not smoking in the TV media only condition compared to controls was 1.53 (95% confidence intervals (CI) 1.02 to 2.29, p = 0.04), and for TV media + LTCN versus controls, 1.67 (95% CI 1.0 to 2.8, p = 0.05). There was no evidence of an extra effect of the local tobacco control network when combined with TV media (odds ratio 1.15, 95% CI 0.74 to 1.78, p = 0.55). The was also no evidence of any intervention effects after the first phase of the TV media campaign, including no effect of varying the intensity of the advertising during this initial phase. Applying these results to a typical population where 28% smoke and 28% are ex-smokers, and where there would be an equal number of quitters and relapsers over an 18 month period without the campaign, suggests that the campaign would reduce smoking prevalence by about 1.2%.

Conclusions: The Health Education Authority for England's anti-smoking TV campaign was effective in reducing smoking prevalence through encouraging smokers to stop and helping prevent relapse in those who had already stopped. The lack of an effect after the first phase of the campaign indicates that if advertising at this intensity is to have an impact, a prolonged campaign is necessary. These results support the UK governments' recent decision to fund similar campaigns, and suggests that anti-smoking TV advertising should be undertaken routinely as an essential component of any population smoking reduction strategy. Reducing smoking prevalence would make a substantial contribution to achieving the UK government's target of preventing 300 000 cancer and heart disease deaths over the next 10 years.