Background
Globally, between 82,000 and 99,000 young people start smoking every day [
1]. Although the proportion of 8–15 year olds in the United Kingdom (UK) who have ever smoked has declined from 18.7% in 1997 to 6% in 2013 [
2], over 200,000 start to smoke each year [
3]. Smoking poses many health risks, including various forms of cancer, cardiovascular disease and respiratory disease, and imposes a significant financial and social burden on society [
4]. Therefore smoking prevention remains an important public health priority [
5]. Efforts to delay or prevent children from starting to smoke are needed because the earlier a child starts to smoke, the less likely they are to quit the habit as an adult, and the more likely they are to die prematurely from a smoking-related disease [
6].
Primary school children represent an important cohort for smoking prevention as regular smoking is not yet established (0.3% ever smoked at age 8–10 years) [
2]. Although these children do not smoke, they may have developed intentions regarding future smoking [
7]. In accordance with the Theory of Planned Behaviour (TPB) [
8], future intentions to smoke predict subsequent smoking behaviour [
7,
9]. In turn, intentions to smoke are shaped by an individual’s smoking-related cognitions such as attitudes (the overall evaluation of smoking) and self-efficacy expectations (a person’s confidence in their ability to stay a non-smoker and to refuse a cigarette) [
8,
10-
12]. Research in adolescents has demonstrated that individual cognitions are formed by distal factors at the interpersonal level, such as family and peers [
13,
14]. Less is known about the factors that influence preadolescent children’s individual cognitions and such knowledge can be used to inform the development of smoking prevention interventions.
Bandura’s social learning theory (SLT) [
15] postulates that smoking behaviour may be directly acquired through modelling the behaviour of significant others. Similarly, attitudes and values towards smoking are partly formed from observing others smoking [
15]. In accordance with social learning theory, previous studies have shown parental, sibling and peer smoking to be significant risk factors for smoking uptake [
16,
17]. Previous research in US preadolescents has shown that having a family member that smokes is associated with more favourable implicit attitudes towards smoking compared with preadolescent children with non-smoking family members [
18]. Similarly, research in Dutch preadolescent children found exposure to parental, sibling and peer smoking to be associated with having more pro-smoking attitudes [
19]. Parental smoking was also related to perceived safety of casual smoking and temptation to smoke in response to smoking related cues such as seeing someone smoke [
19]. Accumulative evidence suggests that there are gender differences concerning the influence of social factors on smoking uptake in adolescents [
20,
21]. For example, mother smoking is reported to influence smoking uptake in girls [
20], whereas father and friend smoking have been found to be stronger influences for boys [
22,
23]. However, the influence of social factors on the antecedents of smoking behaviour in preadolescent boys and girls is less clear. Such knowledge may inform decisions surrounding the inclusion of gender-specific components in smoking prevention interventions targeted at preadolescent children.
Smoking is socially patterned, with high smoking prevalence among low socio-economic status (SES) groups [
24]. This is important as smoking is the leading cause of health inequalities [
25]. Addressing inequalities in tobacco use is therefore a public health priority [
26] and socially deprived areas have been identified as an important target for smoking interventions [
27]. SES is widely regarded as being an important determinant of smoking uptake in young people as children who live and go to school in socially deprived areas are more often exposed to smoking behaviour [
24,
28]. Given that children who live in deprived neighbourhoods are likely to include a predisposition to experiment with smoking [
29], further insight into factors that influence smoking-related cognitions in these groups can provide additional knowledge to inform the development of interventions. A recent and large cross-sectional study of Dutch primary school children (aged 10–11 years) found that the smoking behaviour of the father, mother and other family members was shown to be the most influential on the intention to smoke among children living in a low SES area, though more evidence is needed [
30].
To the authors’ knowledge, the only published UK study that has been conducted with preadolescent children is the Liverpool Longitudinal Study (LLSS) [
31-
33]. The city of Liverpool is one of five metropolitan boroughs in Merseyside, England, and is ranked among the most deprived local authorities in England [
34]. In the LLSS study, 8% of nine year olds had tried smoking, with rates rising to 21% at age 10 and to 27% at age 11. Smoking experimentation was higher amongst boys at age 10, and factors associated with children’s smoking were parental and best friend smoking, curiosity, living in a low income family and residing in a deprived area. However, the LLSS was a largely qualitative study that included a small cohort of children from six primary schools in a localised area of Liverpool. Further, whilst the LLSS examined smoking uptake it did not examine factors associated with intentions to smoke and individual smoking-related cognitions, which are important from a primary prevention perspective.
This paper seeks to extend the LLSS by conducting a large quantitative study and involving a regional population of 9–10 year primary school children from two metropolitan boroughs in Merseyside. Further, the research aims to add to the limited evidence base of studies investigating the influence of social factors on outcomes relevant for primary prevention (i.e. before smoking use or experimentation), in particular among low SES populations. Therefore, the present study aimed to examine the association between social factors (mother/father/sibling/friend smoking) and intentions to smoke and individual smoking-related cognitions (attitude toward smoking, refusal self-efficacy expectations) among preadolescent children from socially deprived areas of the UK. The study investigated social influences on these aspects of cognitive vulnerability toward smoking by gender, as at present there is only limited understanding of the reasons behind gender patterns in smoking [
35].
Results
Descriptive statistics and gender differences for the study sample (n = 1143; Mean age: 9.6 years, SD 0.3; 49.3% boys; 82% participation rate) are presented in Table
1. A high proportion of the children were white British (85.6%), with the remaining children self-identified as black (4.1%), white non-British (1.6%), mixed race (2.8%), Asian (2.6%), Chinese (0.8%) or other non-British descent (2.5%). Over eight out of ten participating children lived within an area ranked within the top 20% for deprivation in England, with 75% within the most deprived decile [
50]. The majority of children (97.5%) reported to have never smoked. CO readings were recorded for 82.7% of children (n = 945). Children’s self-reported non-smoking was confirmed by CO readings (Mean = 1.3, SD ±0.7), with all participants readings below 10 ppm. Children’s perceived smoking behaviour of family and friends is also shown in Table
1. Over half of children (57.3%) reported having at least one family member who smokes; 37.1% mothers, 39.0% fathers and 11.0% of siblings were current smokers. Around a sixth of children had at least one friend who smokes.
Table 1
Descriptive characteristics for the study participants
Demographics
|
Age (years) | 9.6 ± 0.3 | 9.6 ± 0.3 | 9.6 ± 0.3 | 0.06 |
Ethnicity (White British) | 85.6 | 86.1 | 85.0 | 0.75 |
Deprivation level (IMD) | 54.8 ± 16.8 | 54.4 ± 16.7 | 55.2 ± 16.9 | 0.42 |
Social influences
|
Mother smoking | 37.1 | 35.1 | 39.0 | 0.18 |
Father smoking | 39.0 | 39.3 | 38.8 | 0.87 |
Sibling smoking | 11.0 | 9.9 | 12.1 | 0.25 |
Friend smoking† | 16.4 | 21.7 | 11.2 | <0.01* |
Smoking intentions
|
Total non-smoking intentions (range 4-12) | 11.7 ± 0.9 | 11.6 ± 1.0 | 11.8 ± 0.7 | 0.02* |
Self-efficacy
|
Total refusal self-efficacy (range 3-15) | 13.6 ± 3.1 | 13.4 ± 3.3 | 13.8 ± 3.0 | 0.04* |
Attitudes towards smoking
|
Smoking is bad for health (‘definitely yes’) | 88.8 | 85.4 | 92.1 | <0.01* |
Safe to smoke year or two (‘definitely not’) | 62.6 | 62.5 | 62.8 | 0.93 |
Difficult to quit once started (‘definitely yes’) | 50.7 | 50.4 | 51.0 | 0.84 |
Others smoke harmful to you (‘definitely yes’) | 64.3 | 62.5 | 66.0 | 0.22 |
Effects sports performance (‘definitely yes’) | 55.8 | 56.8 | 54.8 | 0.49 |
Makes you gain or lose weight (‘no difference’) | 42.1 | 43.9 | 40.3 | 0.23 |
Whilst a high proportion of children (88.8%) agreed that smoking is ‘definitely’ bad for health, more favourable attitudes towards smoking were observed for the remaining attitude items (Table
1). Approximately six out of ten children indicated that they ‘definitely’ agreed that: ‘it is not safe to smoke for a year or two as long as you quit after that’, ‘the smoke from other people’s cigarettes is harmful to you’ and that ‘smoking effects sports performance’. Further, only half of children believed that it is ‘definitely’ difficult to quit smoking once started, whilst almost six out of ten children stated that smoking makes you either gain or lose weight. Gender differences are also shown in Table
1. Compared to girls, boys had lower non-smoking intentions (P = 0.02) and refusal self-efficacy (P = 0.04). In addition, boys reported having more smoking friends (P < 0.01), whilst a higher proportion of girls than boys believed that smoking is ‘definitely’ bad for health (×
2 = 12.6, P < 0.01, phi = .10). No other sex differences were observed.
Non-smoking intentions
Table
2 shows associations between social factors and non-smoking intentions. After adjustment for refusal self-efficacy, attitudes towards smoking and school and deprivation level, friend smoking was negatively associated with non-smoking intentions in both boys (P < 0.01) and girls (P < 0.01); sibling smoking was negatively associated with non-smoking intentions in girls (P < 0.01) but a positive association was found in boys (P = 0.02). Neither mother nor father smoking behaviour was associated with non-smoking intentions.
Refusal self-efficacy
Table
2 also shows associations between social factors and refusal self-efficacy. After adjustment for non-smoking intentions, attitudes towards smoking and school and deprivation level, friend smoking was negatively associated with refusal self-efficacy in girls (P < 0.01) but not boys (P = 0.07). Neither mother, father nor sibling smoking was associated with refusal self-efficacy.
Table 2
Summary of multilevel regression analysis examining associations between social factors and non-smoking intentions and refusal self-efficacy
Boys
| | | | |
Mother smoking | -0.03 (-0.20, 0.14) | 0.70 | -0.40 (-0.98, 0.18) | 0.18 |
Father smoking | 0.02 (-0.15, 0.18) | 0.86 | -0.25 (-0.74, 0.25) | 0.33 |
Sibling smoking | 0.32 (0.05, 0.60) | 0.02* | -0.49 (-1.33, 0.36) | 0.26 |
Friend smoking† | -0.57 (-0.77, -0.37) | <0.01* | -0.57 (-1.18, 0.04) | 0.07 |
Girls
| |
Mother smoking | -0.04 (-0.15, 0.08) | 0.53 | -0.02 (-0.52, 0.49) | 0.94 |
Father smoking | -0.01 (-0.13, 0.10) | 0.81 | -0.32 (-0.81, 0.17) | 0.19 |
Sibling smoking | -0.38 (-0.55, -0.21) | <0.01* | 0.43 (-0.33, 1.19) | 0.26 |
Friend smoking† | -0.33 (-0.49, -0.17) | <0.01* | -1.14 (-1.86, -0.42) | <0.01* |
Attitudes towards smoking
Table
3 presents associations between social factors and children’s attitudes towards smoking, after adjustment for non-smoking intentions, refusal self-efficacy and school and deprivation level. Significant associations were observed for social factors and attitudes toward smoking on two out of six attitude items for boys; however, no associations were found in girls. Compared to boys with non-smoking friends, boys with smoking friends were less likely to ‘definitely’ believe that smoking is bad for your health (Odds Ratio (OR) = 0.38, 95% CI: 0.21 to 0.69, P < 0.01) and the smoke from other people’s cigarettes is harmful to you (OR = 0.57, 95% CI: 0.35 to 0.91, P = 0.02). In comparison to boys with a non-smoking sibling, boys with a smoking sibling were less likely to ‘definitely’ believe that smoking is bad for your health (OR = 0.45, 95% CI = 0.21 to 0.98, P = 0.04). Mother, father and sibling smoking were not associated with any attitude items in boys or girls.
Table 3
Summary of multilevel binary logistic regression analysis for social factors associated with children’s attitudes towards smoking
Boys
|
Mother smoking | 0.87 (0.50,1.54) | 0.64 | 0.69 (0.47, 1.01) | 0.05 | 0.75 (0.51, 1.09) | 0.13 | 1.18 (0.78, 1.80) | 0.44 | 1.36 (0.91, 2.04) | 0.14 | 1.28 (0.88, 1.85) | 0.19 |
Father smoking | 0.68 (0.39, 1.17) | 0.16 | 1.18 (0.82, 1.71) | 0.37 | 0.96 (0.67, 1.37) | 0.81 | 1.15 (0.77, 1.73) | 0.48 | 1.02 (0.69, 1.50) | 0.92 | 0.91 (0.64, 1.29) | 0.59 |
Sibling smoking | 0.45 (0.21, 0.98) | 0.04* | 0.95 (0.52, 1.76) | 0.88 | 1.11 (0.60, 2.05) | 0.74 | 1.85 (0.93, 3.69) | 0.08 | 0.67 (0.35, 1.28) | 0.23 | 1.19 (0.66, 2.14) | 0.57 |
Friend smoking | 0.38 (0.21, 0.69) | <0.01* | 0.73 (0.47, 1.15) | 0.18 | 1.13 (0.83, 2.08) | 0.24 | 0.57 (0.35, 0.91) | 0.02 | 1.07 (0.66, 1.72) | 0.80 | 0.65 (0.42, 1.02) | 0.06 |
Girls
|
Mother smoking | 1.09 (0.52, 2.20) | 0.82 | 0.69 (0.47, 1.02) | 0.07 | 0.86 (0.59, 1.26) | 0.44 | 0.81 (0.53, 1.24) | 0.32 | 1.18 (0.78, 1.77) | 0.43 | 1.13 (0.78, 1.64) | 0.53 |
Father smoking | 0.82 (0.41, 1.64) | 0.58 | 1.00 (0.68, 1.47) | 1.00 | 1.29 (0.89, 1.86) | 0.18 | 1.33 (0.87, 2.03) | 0.18 | 0.68 (0.46, 1.01) | 0.05 | 1.12 (0.78, 1.60) | 0.54 |
Sibling smoking | 1.69 (0.55, 5.15) | 0.36 | 1.75 (0.95, 3.21) | 0.07 | 0.84 (0.47, 1.49) | 0.55 | 1.04 (0.55, 1.95) | 0.90 | 0.71 (0.39, 1.29) | 0.26 | 0.92 (0.57, 1.47) | 0.73 |
Friend smoking | 1.30 (0.49, 3.46) | 0.60 | 0.77 (0.44, 1.33) | 0.35 | 0.85 (0.50, 1.47) | 0.57 | 1.32 (0.72, 2.43) | 0.36 | 0.96 (0.54, 1.69) | 0.88 | 1.11 (0.65, 1.88) | 0.71 |
Discussion
The aim of the present study was to identify whether mother, father, sibling and friend smoking were associated with cognitive vulnerability to smoking among 9–10 year old children from deprived neighbourhoods in Merseyside, England. The results indicate that sibling and friend smoking may represent more salient influences on children’s cognitive vulnerability to smoking than mother and father smoking. Moreover, some differential effects were observed by gender, suggesting that social factors may, in part, influence the antecedents of smoking behaviour in boys and girls differently. These findings extend the LLSS [
31-
33] and add to the limited evidence base in preadolescent children.
SLT proposes that behaviour, perceptions of behaviour and the environment interact to influence one another [
15]. In accordance with SLT [
15], parents have previously been considered to be the most important influences on children during the primary school years [
53], while peer influences become increasingly more salient during the adolescent years [
54]. In the present study, mother (37%) and father smoking (39%) was relatively high, which is reflective of the local context in Merseyside where levels of smoking and deprivation are higher than the national average [
4,
38]. Children of smoking parents are at a higher risk of having susceptible smoking cognitions [
12,
18,
19,
54-
56] and initiating smoking [
16], especially those in lower socio-economic status groups [
30]. However, in the current study, no associations were observed between mother or father smoking and children’s non-smoking intentions, smoking-related attitudes and refusal self-efficacy. A possible explanation for the divergence in findings is that whilst this study examined independent influences of mother and father smoking, other studies [
12,
18,
19,
54-
56] utilised a combined parental smoking variable for analyses. To check this, we conducted additional analysis using a combined parental smoking variable but found no further associations. Alternatively, whilst children are aware that their parents smoke, their exposure to smokers may vary [
19] as a result of regional public health campaigns to protect children from smoking such as “Take 7 Steps Out” (see
www.tobaccofreefutures.org). In addition, smoking parents may communicate non-smoking expectations to their offspring or display disapproval of child smoking, which has been found to be protective against smoking intention and initiation [
16,
30,
53,
57,
58]. Nevertheless, further research is needed to examine the influence of mother or father smoking behaviour on children’s cognitive vulnerability towards smoking.
The results of the present study suggest that sibling and friend smoking may be important influences on preadolescent children’s cognitive vulnerability towards smoking. Friend smoking was negatively associated with non-smoking intentions in both boys and girls, extending previous studies in adolescents that have found peer smoking to be related to smoking uptake [
17]. The influence of sibling smoking, however, differed by gender; sibling smoking was negatively associated with non-smoking intentions in girls, which is consistent with the accumulative evidence [
16]. Conversely, a positive association was apparent in boys, suggesting that having a smoking sibling strengthened their non-smoking intentions. This finding was unexpected but may reflect parent disapproval of sibling smoking and communication of non-smoking expectations [
53,
57], although more research is needed. Gender differences were also found in relation to refusal self-efficacy and attitudes toward smoking; friend smoking was negatively associated with refusal self-efficacy in girls but not boys. Further, boys with a smoking friend or sibling had less negative attitudes towards smoking regarding the health consequences of smoking and the harms of others’ smoke though no associations were observed in girls. Boys reported having more smoking friends than girls, which may have contributed to these effects since children who perceive that many of their friends advocate or engage in smoking are more likely to develop pro-smoking attitudes [
19]. Further, boys may assume that smoking is not as harmful, otherwise their friend/sibling would not smoke.
To the authors’ knowledge, only one other study has concurrently examined the role of parent, sibling and friend smoking in shaping preadolescents cognitive vulnerability to smoking [
19]. Using structural equation modelling, Schuck et al. [
19] found no direct effects of parental smoking, sibling smoking or peer smoking on 9–12 year old children’s susceptibility towards smoking. However, peer, sibling and, in particular, parent smoking was associated with perceiving more pros of smoking. Further, parent smoking was positively associated with perceived safety of casual smoking and cue-triggered wanting to smoke [
19]. These findings are inconsistent with the current study and may reflect cultural differences and different methodologies employed. Future studies examining the influence of the social environment in preadolescents are warranted.
The findings observed for friend and sibling smoking on children’s cognitive vulnerability to smoking could be attributed to several factors. Firstly, while children in the early primary school years are likely to spend a lot of time with their parents, it is probable that older children (ages 8 years and over) spend more time with siblings (who share more similarities and social networks) and friends. The findings may therefore reflect the fact that friends and siblings increasingly represent children’s predominant social environment, and are likely to be more proximal influences on children’s vulnerability to smoking than parents. Second, peer and sibling smoking behaviour is likely to be less overt than parent smoking and as a consequence may be perceived by other children as exciting or cool and socially desirable [
59]. Peer groups are known to share common attitudes and behaviours [
60,
61]; smokers may communicate pro-smoking attitudes and approval of smoking initiation [
62], which in turn could influence intentions to smoke and smoking-related cognitions among children. Third, whilst the majority of children stated that they had never tried smoking (97.5%), around a sixth believed that they knew a friend that had. It is possible that children may have underreported their own smoking status, or perhaps, overestimated their friends smoking habits. Given that overestimation of smoking prevalence is related to smoking initiation in preadolescent children [
63], overestimation of friend and sibling smoking by children in the current study may have influenced their cognitive aspects around smoking. Taken together, the results suggest that friend and sibling smoking behaviours may contribute to preadolescent children’s cognitive vulnerability to smoking. However, more evidence is required and research is needed to determine the mechanisms associated with peer and sibling influence.
Encouragingly, most children displayed strong non-smoking intentions and refusal self-efficacy. Reflecting the high intention not to smoke, few children had tried smoking (2.5%), which is consistent with other studies in preadolescent children [
31,
32]. NICE guidance [
44] states that smoking prevention efforts may be more effective if started in primary school. Given the low rates of smoking experimentation, 9–10 year old children could be an appropriate cohort to target for primary prevention. While encouraging, results regarding children’s high refusal self-efficacy should be interpreted with caution because children at this age may not have encountered situations where they have been put to the test to resist influences to smoke from others [
55]. Because decreases in self-efficacy have been associated with smoking onset and continuation in adolescents [
64,
65], efforts to maintain the strength of preadolescent children’s smoking refusal self-efficacy may be effective in preventing them from starting to smoke. Previous school-based interventions that have taught adolescents to deal with direct pressure to smoke have demonstrated modest positive results on smoking behaviour [
66,
67]. Prevention interventions may also need to address children’s attitudes toward smoking, as over a third of participants in this study did not recognise with certainty that short term smoking is not safe, that smoking is addictive, that others smoke is harmful, that smoking effects sport performance and that smoking per se does not influence weight. More positive attitudes toward smoking may predict intentions to smoke in the future and later smoking behaviour [
8,
10-
12].
Previous research has called for further investigations into the need for gender-specific approaches to prevent smoking [
30]. The current study found gender differences in the influence of social factors. In addition, compared with girls, boys were less likely to believe smoking is ‘definitely’ bad for health, and expressed lower non-smoking intentions and refusal self-efficacy. However, no clear pattern emerges from the data and qualitative research may prove useful in revealing the thought processes through which boys and girls form these smoking-related cognitions. Previous research with Dutch preadolescent children has reported it unnecessary to develop separate smoking prevention programmes for preadolescent children [
64]. Given that the influences on boys’ and girls’ intentions to smoke were broadly similar, the results of the present study provide tentative support to this statement. Nevertheless, intervention and prevention efforts aimed at preadolescents may benefit from tailored messaging that dispels myths about the health consequences of smoking and exposure to smoke as well as strengthening refusal self-efficacy.
This study extends the smoking literature in preadolescent children by examining the influence of social factors (mother, father, sibling and friends) on cognitive vulnerability to smoking among a large sample of 9–10 year old children from deprived neighbourhoods. However, the study has a number of limitations. First, the analysis is based on a self-reported cross-sectional survey; therefore causal relationships cannot be established. In addition, the study examined influences on intentions to smoke and smoking-related cognitions, which may or may not result in smoking initiation at a later age [
30]. Nevertheless, previous research demonstrates that these individual level factors are predictive of future smoking behaviour [
8,
10-
12]. Second, children self-reported their smoking behaviour, which introduces the possibility of under or over reporting because of recall or social desirability [
55]. However, self-reported smoking has been demonstrated to be accurate provided confidentiality is assured [
68]. Moreover, children’s self-reported non-smoking status was confirmed using an objective measure of smoking. Third, direct measures of parental and friend smoking behaviours were not available, though previous research has demonstrated that children can reliably assess the smoking behaviour of others in their social environment [
69]. Fourth, this study only examined the influence of biological family members (mother, father and sibling) and did not assess the influence of parental structure (i.e. one-parent vs. two-parent families or step parents). Previous research has shown adolescents who live with both biological parents smoke less than those living in single-parent families [
70]. In addition, we did not collect gender-specific data on sibling smoking and therefore could not distinguish between the influence of brothers or sisters on the outcome variables. Finally, results are drawn from two deprived local authorities with high adult smoking prevalence, which limits the generalisability of results to other regions of England. However, given that smoking is socially patterned, findings can be generalised to similar urban areas with high levels of deprivation, where the need for smoking prevention is proportionally greater.
Competing interests
The authors declare that they have no competing interests.
Authors’ contributions
CEM drafted the manuscript and together with JT was responsible for data collection and analyses. LF conceived and managed the project as principal investigator. CM, JT, SF, RM, LP, MU and LF made substantial contributions to the study design, interpretation of data and editing the manuscript. All authors read and approved the final manuscript.