Our 38-year follow-up of educational differences in smoking revealed that daily smoking decreased over time but was more common among men and the less educated during the whole study period. However, from the late 1970s, both absolute and relative differences in smoking between educational groups widened suggesting increasing inequalities in health in the future.
Trends for daily smoking seemed to be associated with the price of cigarettes, especially in the 2000s. A recent study including European countries proposed that lower socio-economic groups are more price sensitive (Hu et al. 2017). Our findings support this notion. Age-stratified examination showed that daily smoking declined over time as a general rule. Still, among the 45–64-year-old less educated women, smoking increased during the study period, possibly indicating a cohort effect (Helakorpi et al. 2008).
As Finland aims to be tobacco and nicotine free by 2030 (Finlex 2016), our results implicate that more attention should be especially taken concerning those in a lower socio-economic position. The support for smoking cessation should be enhanced, which along with large-scale campaigning, has been one of the weakest points of the Finnish tobacco control (Joossens and Raw 2017). As socio-economic differences in smoking cessation are observable in Finland (Bosdriesz et al. 2015), stop smoking services should be better targeted at lower socio-economic groups to reduce inequalities in health (Brown et al. 2014). Untargeted cessation services may reduce smoking altogether while still increasing inequalities in smoking (Brown et al. 2014).
The results support the general view that price is a strong instrument of tobacco control policy. The method of small gradual price increases has been used in Finland since 2009. The government has decided on a series of smaller consecutive tax increases which would gradually increase the average price of cigarettes altogether by 30% in 2016–2019. It has been estimated that long-term annual 10% increases in price would reduce socio-economic inequality in lung cancer mortality in England and in Wales (Soerjomataram et al. 2011). Price increases have also been considered to decrease inequalities in all-cause mortality in Finland (Kulik et al. 2013). Thus, further long-term price increases could be recommended together with national anti-tobacco campaigns with an emphasis on stopping smoking and help for quitting. This could lead to public discussion on tobacco by the media and could then also reach the less educated who are not easily reached by conventional methods. There is positive evidence from the past about a combined ‘shock effect’ of tobacco control measures (Pekurinen and Valtonen 1987), but it is important to be aware that sudden large tax increase may also backfire in terms of the illegal sales, for example.
Finland is at the final stage of the tobacco epidemic model, where the proportion of smokers and tobacco-related mortality is declining (Thun et al. 2012). However, the age-stratified examination revealed that there still are population groups with increasing smoking rates. We might see an increase in tobacco-related mortality among older less educated women in the future. This can be seen as part of the proposed fifth stage of the tobacco epidemic, where smoking among the lower socio-economic groups does not decrease (Dixon and Banwell 2009).
The role of tobacco control legislation in socio-economic differences in smoking has been studied, but its effect is inconclusive. Smoke-free workplace legislation in Finland has had a relatively largest effect on the decrease in smoking among industrial workers with less education (Heloma et al. 2001). Another study found the impact of the TCA less pronounced among male lower socio-economic groups in the early 2000s (Helakorpi et al. 2008). Educational differences in smoking have persisted or increased in Germany in the 2000s after implementing several tobacco control measures, such as smoke-free laws (Hoebel et al. 2018). In Switzerland, the implementation of a public smoking ban coincided with a widening of inequalities between socio-economic groups in 1995–2014 in terms of the smoking prevalence and quit ratio (Sandoval et al. 2018).
Point-of-sale ban decreased the smoking more among the less educated than among the highly educated in England (Kuipers et al. 2017). Pictorial warnings affect educational groups similarly (Brewer et al. 2016), but no studies on the impact of plain packaging have been published. One study suggests that pictorial health warning labels on plain packaging may affect smokers with higher socio-economic position more than smokers with lower socio-economic position (Swayampakala et al. 2017). Tobacco endgame could be seen as a strong measure to decrease and to eradicate inequalities in health (McDaniel et al. 2016). To our knowledge, no studies have examined the effects of the tobacco endgame as the target of the policy on socio-economic differences in smoking. The impact of the endgame and other novel tobacco control policy actions on inequalities in health should be monitored in the future.
Our results, in accordance with earlier studies (Hoebel et al. 2018; Lahelma et al. 2016; Hu et al. 2017), warrant further actions on reducing health inequalities. Even if smoking has declined among educational groups in Finland, socio-economic differences between these groups have widened. If the present trend with widening or relatively unchanged differences between educational groups continues and no new measures to change the trend are developed and implemented, it will predominantly be the less educated who are still smoking at the goal of the endgame in 2030.
Strengths and limitations
Certain limitations need to be taken into account when interpreting our results. The declining response rate over time is a limitation. Earlier studies have shown that younger men, smokers, and the less educated are less likely to respond to surveys, and underreporting of smoking likely occurs (Reinikainen et al. 2018; Kopra et al. 2015). Observed differences in smoking between educational groups could have been even more pronounced had the less educated responded more actively. The number of observations in 2016 was lower compared with other study years, which may have influenced the power of statistical tests. Our results, especially from the last survey years, need to be interpreted with caution. The stratification of education according to tertiles could not always be determined exactly at 33% of the distribution.
This study has several strengths. The follow-up time is exceptionally long. Similar measures of education and smoking were used over the study period. The data were randomly sampled, and we used post-stratification weights in order to match the data distribution to the age–sex distribution of the general Finnish adult population. We were able to control the impact of the changes in the real price index on smoking.
Since the late 1970s, smoking has decreased but differences between socio-economic groups have widened. More instruments for eradicating inequalities in health are needed, especially focusing on lower socio-economic groups. In addition to better support for smoking cessation and larger tax increases, other tobacco control policy actions should be considered. With even further actions, the objective of a tobacco and nicotine free Finland by 2030 may be attainable.