Study design

This is a cross-sectional study based on the 2021 ITC EUREST-PLUS Spain Survey, which is a follow-up survey of a nationally representative sample of adults aged ≥18 years who smoked at the time of recruitment in 2016 (Wave 1). Respondents were recontacted in 2018 (Wave 2) and 2021 (Wave 3). This analysis uses cross-sectional data from Wave 3. The original sample was randomly selected using a multistage design within geographical strata. Respondents interviewed in 2018 who agreed to be recontacted in the future were invited to participate in 2021. Respondents lost to follow-up were replaced with new participants selected from newly screened households using the same sampling frame. The final sample consisted of 1006 respondents who smoked or had quit smoking and provided valid information; 56.7% had been interviewed in the previous two waves. Further details of the methods can be found elsewhere⁶. The survey received ethical approval from the Research Ethics Boards of the Bellvitge University Hospital, Spain (PR248/17) and the University of Waterloo, Canada (REB#41105). All participants gave consent for participation.

Measures

We asked participants for their opinions on smoke-free regulations in various indoor/outdoor places, some already regulated and some unregulated, and their support for total outdoor bans, most of which are not regulated by current law (Table 1).

Opinions on smoke-free regulations in indoor/outdoor places

These were assessed by asking: ‘At which of the following places do you think smoking should be allowed?’. Settings assessed were schoolyards of primary and secondary schools, outdoor terraces of of bars/pubs and restaurants, outdoor bus stops and subway/train stations, private cars (with pre-school children, with children aged <16 years, with others who do not smoke), within 5 m of public building entrances, beaches, and open stadiums for events. The response options were ‘yes’ or ‘no’. We describe ‘no’ responses as reflecting a favorable opinion on smoke-free regulation in a specific place. ‘Refused’ and ‘Don't know’ (RDK) responses were excluded (0.0–3.4% of responses) (Supplementary file Table S1).

Support for further total outdoor smoking bans

This was measured by the question: ‘Do you support or oppose a complete smoking ban in outdoor areas of the following places?’. Settings assessed were terraces of restaurants/bars/pubs, public buildings including entrances, markets/shopping centers, and swimming pools. The response options were ‘strongly support’, ‘support’, ‘oppose’, ‘strongly oppose’, recoded as support/oppose. We describe ‘support’ to reflect support for further outdoor smoking bans. RDK responses were excluded (2.0–4.4% of responses) (Supplementary file Table S1).

Sociodemographic characteristics

These were sex (male, female), age (<25, 25–39, 40–54, ≥55 years), education level (low: up to lower secondary education; medium: upper secondary to short-cycle tertiary education; high: completed university education), living with children aged <18 (yes/no), significant others who smoke [assuming that having a partner who smokes is more relevant than having friends who smoke, we categorized this variable as ‘a partner who smokes’ (regardless of having friends who smoke), ‘friends but not a partner who smokes’, and ‘no significant others who smoke’].

Smoking-related characteristics

These were smoking status (current smoking: having smoked ≥100 cigarettes in lifetime and currently smoking cigarettes at least less than monthly; former smoking: having quit since the two previous surveys)⁹; nicotine dependence, assessed with the Heaviness of Smoking Index¹⁰ (categorized as low: 0–2 points, moderate: 3–4 points, high: 5–6 points; for former smoking the score was 0); and having tried to quit in the last 18 months (yes/no).

Belief about the harmfulness of SHS to others

This was assessed with the statement: ‘Cigarette smoke is dangerous to non-smokers’. The response options were ‘strongly agree’, ‘agree’, ‘neither agree nor disagree’, ‘disagree’, ‘strongly disagree’, which were recoded as ‘agree’, ‘neither agree nor disagree’, ‘disagree’. RDK responses were excluded (1.3%) (Supplementary file Table S1).

Analysis

We estimate the prevalence (with 95% confidence interval, CI) of favorable opinions on smoke-free regulations in different places and support for further outdoor smoking bans, stratifying by the independent variables. We used Poisson regression models with robust variance to estimate prevalence ratios (PR) and 95% CI for comparing opinions on smoke-free regulation and support for further outdoor smoking bans by all independent variables, adjusting for age, sex, and education level. All tests were two-tailed and statistical significance was set at p<0.05. All analyses used bootstrap replicate weights derived from the complex sampling design. We used Stata^® v.14 (Texas, USA) for all analyses.

Opinions on smoke-free regulation in indoor/outdoor places

Tables 2 and 3 show the prevalence of favorable opinions on smoke-free regulations in different settings. Among adults who smoke or recently quit, most think that smoking should not be allowed in schoolyards of primary (98.0%; 95% CI: 96.9–99.1) and secondary schools (97.4%; 95% CI: 96.2–98.6) (Table 2), with no differences according to the independent variables. High versus low nicotine dependence, and not believing versus believing that SHS is harmful to others were factors positively associated with this opinion in these settings (Figure 1) (and Supplementary file Table S2).

Figure 1

Factors associated with favorable opinions on smoke-free regulation in outdoor places with different regulation among a nationally representative sample of adults who smoke and recently quit smoking, ITC EUREST-PLUS Spain Survey, Spain, 2021 (N=1006)

A favorable opinion on smoke-free regulation was less prevalent for outdoor transportation (bus stops: 62.3%; 95% CI: 57.9–66.7; subways/train stations: 78.3%; 95% CI: 75.0–81.7) (Table 2). Those who formerly smoked, have low nicotine dependence, and believe that SHS is harmful to others are more likely to agree with smoke-free regulations in these settings. As shown in Figure 1, factors positively associated with this opinion were moderate/high (vs low) education level, not having significant others who smoke (vs having a partner who smokes) and former (vs current) smoking. In contrast, factors negatively associated were moderate/high nicotine dependence and neither agreeing nor disagreeing with the statement that SHS is harmful to others (Figure 1) (and Supplementary file Table S2).

Conversely, few adults who smoke or recently quit have favorable opinions on smoke-free regulation for outdoor terraces of bars/pubs (15.2%) and restaurants (18.4%); this is higher among those who have quit smoking (27.8% and 30.0%, respectively) (Table 2). Factors positively associated with this opinion were having no significant others who smoke, having previously smoked, and having recently tried to quit smoking (Figure 1) (and Supplementary file Table S2).

Another setting for which adults who smoke or recently quit are most in favor of smoking restrictions was in private cars with: pre-school children (97.5%; 95% CI: 96.4–98.7), children aged <16 years (96.9%; 95% CI: 95.7–98.1), and others who do not smoke (87.8%; 95% CI: 84.5–91.1) (Table 3). Favorable opinions about smoking restrictions in a car with others who do not smoke were more frequent among those without significant others who smoke, who had previously smoked, and believing that SHS is harmful to others (all >90%). Having no significant others who smoke and having previously smoked were more positively associated with support for such a regulation, whereas being aged 40–54 years (vs the oldest age group) and disagreeing and neither agreeing nor disagreeing that SHS is harmful to others were negatively associated with such support (Figure 2) (and Supplementary file Table S3).

Figure 2

Factors associated with favorable opinions on smoke-free regulation in outdoor places currently not regulated by law among a nationally representative sample of adults who smoke and recently quit smoking, ITC EUREST-PLUS Spain Survey, Spain, 2021 (N=1006)

Around 30–60% of adults who smoke or recently quit are in favor of smoke-free regulations on beaches, at public building entrances and in open-air stadiums, particularly those with no significant others who smoked, have previously smoked, and believe that others are adversely affected by SHS (Table 3). Factors positively associated with this opinion were moderate education level, the absence of a significant other who smokes, and having previously smoked. Conversely, moderate/high nicotine dependence and neither agreeing nor disagreeing with the statement that SHS is harmful to others were more negatively associated with this opinion (Figure 2) (and Supplementary file Table S3).

Support for further total outdoor smoking bans

Less than 60% of adults who smoke or recently quit support further complete smoking bans in outdoor environments (Table 4), including markets/shopping centers (57.2%; 95% CI: 51.7–62.6), public building entrances (50.9%; 95% CI: 46.2–55.5), and swimming pools (43.4%; 95% CI: 39.2–47.7). In this last setting, the highest levels of support come from older participants (48.9%; 95% CI: 42.5–55.3), with no significant others who smoke (62.9%; 95% CI: 52.5–73.3) and believing that SHS is harmful to others (46.5%; 95% CI: 41.8–51.3) (Table 4). Support for smoke-free swimming pools was positively associated with having no significant others who smoke and having previously smoked; negatively associated factors included being aged 25–39 years, moderate nicotine dependence, and not agreeing or disagreeing with the statement that SHS is harmful to others. Only moderate education level and having previously smoked were positively associated with support for public building entrances (Figure 3) (and Supplementary file Table S4).

Figure 3

Factors associated with support for further total outdoor smoking bans among a nationally representative sample of adults who smoke and recently quit smoking, ITC EUREST-PLUS Spain Survey, Spain, 2021 (N=1006)

Restaurants/bars/pubs were found to have the lowest level of support for further total outdoor smoking bans (29.2%; 95% CI: 24.9–33.6) (Table 4). The only factor negatively associated with such support was disagreeing or neither agreeing nor disagreeing with the statement that SHS is harmful to others (Figure 3) (and Supplementary file Table S4).

Opinions on smoke-free regulation in indoor/outdoor places

Given that smoking is already banned in schoolyards of primary and secondary schools, and that these are places where minors are present, the opinion on smoke-free regulations in these settings is highly favorable. The same occurs for cars with minors, and slightly less for cars with adults who do not smoke, although private cars are not covered by the current legislation (Table 1). Compared to the 2016 survey, favorable opinions in these settings increased slightly since then (i.e. >90%)¹¹. This may reflect the public’s awareness of the health effects of SHS exposure on vulnerable populations, such as children¹². It may also be an indicator of their readiness to introduce regulations on smoking in private cars with vulnerable groups such as children and pregnant women, both circumstances in which smoking may be banned under further legislation, as in other European countries³. In some countries, the prevalence of voluntary smoke-free rules in private cars with children was as high as 65% in 2010–2011, consistent with the widely expressed support (>80%) for banning smoking in cars with children^11,13.

Spanish tobacco Law 28/2005 regulated smoking on public transportation, but only indoors. Although moderate proportions of adults who smoke are in favor of not allowing smoking in outdoor areas, we observed important increases compared to opinions expressed in 2016, by 30 percentage points for bus stops and 15 percentage points for subway/train stations¹¹, suggesting the feasibility of further regulation in these settings. Outdoor terraces of restaurants/bars/pubs receive, however, less favorable opinions. This was not surprising, because a weak regulation was initially established for the indoor areas of these venues, which was amended (by Law 42/2010) to a complete ban on smoking indoors and a partial ban outdoors, affecting those terraces with a roof and more than two walls or faces^8,14. While favorable opinions increased from 3.4% to 15.2% for bar/pub terraces and from 4.2% to 18.4% for restaurant terraces between 2016 and 2021, they remain relatively low and consistent with observed low compliance¹⁵. This may be because people usually perceive SHS to dissipate quickly and the potential for exposure is low. However, there is evidence that SHS exposure can be as high as in indoor smoking areas¹⁶. Therefore, further regulation is expected to include these settings. The growing support for regulation of these settings in our study and others¹⁷, suggests that it can be implemented. In fact, smoking in these settings was already regulated during the COVID-19 pandemic in Spain^18,19, based on WHO recommendations in response to the pandemic²⁰, although this was a temporary measure.

Another setting where SHS exposure is typically underestimated is access to public buildings. Our data show that only 36% of adults who currently smoke or recently quit favor regulating smoking in this setting, but this prevalence is higher than that in 2016 (20.5%). Although some studies have demonstrated the potential for outdoor smoke to drift indoors^16,21, smoking bans in building entrances are still rare, having been implemented in only a few jurisdictions^22,23. The same is true for beaches and stadiums, although there is increasing favorable opinion on regulations in these settings²⁴. In Spain, voluntary regulations for beaches are increasing²⁵. In Barcelona, a city council intervention that included a smoking ban on beaches was well accepted and effective in reducing smoking and the visibility of people smoking²⁶.

Support for further total outdoor smoking bans

Support for complete smoking bans in outdoor places is generally moderate (40–60% for public buildings entrances, markets/shopping centers, and swimming pools), which is consistent with evidence showing high support (69%) for smoke-free outdoor non-hospitality settings (playgrounds, streets, beaches), with no difference between countries with and without existing regulations²⁷. However, total outdoor bans in restaurants/bars/pubs, which are partially regulated in Spain, had the lowest support, probably due to strong lobbying from the hospitality sector since the enactment of the Law 28/2005²⁸, which predicted negative economic consequences for the hospitality sector that never materialized²⁹. Cultural reasons may also be linked to low support in these settings. The terraces are places where people socialize, so cultural changes are hard to achieve. Although low support in these settings among adults who smoke has also been found in other countries without regulation^30,31, it increased after ban implementation^32-34.

Our data indicate relevant factors associated with opinion and support for smoke-free outdoor environments, which are particularly strong among those who quit smoking, without significant others who smoke, and believing that SHS is harmful to others. These findings highlight the importance of promoting not only cessation but also educational campaigns focusing on the health effects of SHS exposure. In Spain, there are several local initiatives to ban smoking in outdoor settings, such as beaches, stadiums, and bus stops, with good acceptance²⁵. It therefore seems feasible to include smoke-free outdoor areas in national legislation³⁵. Nevertheless, it is crucial to raise awareness of SHS exposure in outdoor environments, especially on the terraces of restaurants, bars, and pubs, where exposure can be high¹⁵.

Strengths and limitations

The main strength of this research is its robust survey design, which allowed us to study a nationally representative sample of adults who smoke and recently quit smoking in Spain. The use of the same questionnaire as in previous surveys allowed us to assess the reliability of the results; the current survey included additional settings that will be useful to explore changes in opinion and support for further regulation in the near future, examining several socio-economic and smoking-related variables.

A limitation of this study is the cross-sectional nature of the analysis, which precludes any causal relationship between the variables examined. In addition, responses may be subject to information bias, although the results are consistent with the previous survey¹¹, with higher favorable opinions and support for smoke-free policies in all settings. Also, we did not adjust the analyses for wave of recruitment to account for the number of times participants had previously responded to the survey, nor did we stratify for this variable to assess effect modification; therefore, we cannot disregard some overestimation of favorable opinions and support. Finally, although we used a common questionnaire used in other ITC surveys, our results are not necessarily generalizable to other countries.