The impact of TV mass media campaigns on calls to a national quitline and the use of prescribed nicotine replacement therapy: a Structural vector autoregression analysis

Aims: To estimate 1) the immediate impact; 2) the cumulative impact; and 3) the duration of impact of Scottish tobacco control TV mass media campaigns (MMCs) on smoking cessation activity, as measured by calls to Smokeline and the volume of prescribed nicotine replacement therapy (NRT).Design: Multivariate time series analysis using secondary data on population level measures of exposure to TV MMCs broadcast and smoking cessation activity between 2003 and 2012.Setting and participants: Population of Scotland.Measurements: Adult television viewer ratings (TVRs) as a measure of exposure to Scottish mass media campaigns in the adult population; monthly calls to NHS Smokeline; and the monthly volume of prescribed NRT as measured by gross ingredient costs (GIC).Findings: Tobacco control TVRs were associated with an increase in calls to Smokeline but not an increase in the volume of prescribed NRT. A one standard deviation increase of 194 tobacco control TVRs led to an immediate and significant increase of 385.9 (95% CI: 171.0, 600.7) calls to Smokeline (unadjusted model) within one month. When adjusted for seasonality the impact was reduced but the increase in calls remained significant (226.3 calls, 95% CI: 37.3, 415.3). The cumulative impact on Smokeline calls remained significant for 6 months after broadcast in the unadjusted model and 18 months in the adjusted model. However, an increase in tobacco control TVRs of 194 failed to have a significant impact on the GIC of prescribed NRT in either the unadjusted (£1361.4, 95% CI: - £9138.0, £11860.9) or adjusted (£6297.1, 95% CI: -£2587.8, £15182.1) models.Conclusions: Tobacco control television mass media campaigns broadcast in Scotland between 2003 and 2012 were effective in triggering calls to Smokeline but did not significantly increase the use of prescribed nicotine replacement therapy by adult smokers. The impact on calls to Smokeline occurred immediately within one month of broadcast and was sustained for at least 6 months