Carburización como método de preparación de las superficies de Si.

In their systematic review of the literature, Aveyard et al (2004a) assessed the evidence that there is between-school variability in smoking prevalence (i.e. that the school context influences pupil smoking. Their aim included the examination o f studies for possible confounding by pupil characteristics (compositional characteristics) in order to assess the statistical evidence for school-level effects (contextual / collective characteristics, e.g. smoking policy). In order to compare different studies, they adopted the use o f a school effect odds ratio (OR) to contrast the odds of smoking in a school one standard deviation above the average school with the odds o f smoking in the average school in each study. The greater the school effect OR in each study, the greater the school effect of whatever contextual factor is being studied. In doing this, five studies showed that schools did vary (i.e. there was a school effect), but compositional confounding needed to be accounted for. Aveyard et

al suggested that while statistical associations between individual school

factors and smoking prevalence were generally weak, there was significant evidence for a school effect on smoking prevalence and that the “strongest and most consistent evidence relates reduced smoking by pupils to schools’ policies banning smoking and enforcing this through punishment” (2004a:2262). Similarly, Pentz et al concluded that “simply having a fonnal

statement of policy is not likely to impact on adolescent smoking - the policy should emphasize smoking prevention and be actively implemented’ (1989:860 - highlighting not in original). Applying generic theory by Bodansky regarding the effectiveness of legislation on human behaviour, to national tobacco control policy, Wold et al (2004a) argue that policy is likely to be most effective when accompanied by, among other things, adequate enforcement and threats of sanctions. If we apply these to schools, then it is the nature o f enforcement that moderates another o f Bodansky’s factors for effective policy: compliance. If there is variation in enforcement, then this is likely to lead to variation in both compliance and policy effectiveness. Trinidad et al (2004) echo the importance of enforcement arguing that the weight o f evidence suggests that if smoking bans are not consistently enforced then pupils will receive mixed messages and that consistent enforcement is associated with lower smoking rates. Griesbach & Currie (2001) also found an association between consistent enforcement of pupil smoking restrictions n given places and lower pupil reporting o f seeing other pupils smoking in those areas. It has also been suggested that frequent and formal enforcement o f staff bans may be necessary in order to ensure that smoke-free policies are not undermined (Peck et al, 1993). Gordon & Turner (2003a) and Darling & Reeder (2003) agree that it is not the policy, but the extent to which it is consistently enforced that is important: poorly enforced policy makes smoking easy and tempting for adolescents.

Some work brings the importance o f policy enforcement into question. One study found that having a clear strategy for policy enforcement did not appear to be related to the policy’s success (Pickett et al, 1999). Similarly, Moore et

al (2001) found that, although in schools where pupil policy enforcement was

low pupils were at greater risk o f being smokers than where it was high (OR = 1.41), neither enforcement o f staff or pupil smoking policies were significantly associated with reduced pupil smoking prevalence. Darling et al (2006) also discovered no association between adolescent smoking prevalence and school smoking policies which included sanctions for students caught breaking the policy. In addition, Reitsma & Manske (2004) discovered that secondary schools with weaker policy enforcement had fewer smokers. While this

contradicts the argument made for the importance o f smoking policy enforcement, the cross-sectional study design (as in much of this literature) means that causality cannot be assessed and it may be that schools with less smoking have less need to strongly enforce policy. Interestingly, the authors compared secondary and elemeriary schools with the latter showing strong enforcement associated with lower smoking. However, they suggest that this could result from the fact that students were observed smoking on school grounds in only 1 elementary school out of 57 surveyed (2%), compared to in 90% o f 29 secondary schools (around 26 schools).

Despite the potential importance of enforcement, while school smoking bans are common, they are generally poorly complied with and therefore enforcement is a key area o f policy that needs investigation (Wakefield et al, 2000). Their findings suggest that a school ban alone does not have a significant effect on the stage o f smoking uptake, but that an enforced ban is significantly associated with lower smoking prevalence. At the threshold between all five stages of their smoking transition model (each stage representing an increasingly developed smoking habit) enforced school bans were associated with an 11% reduction in the likelihood o f a pupil crossing that threshold. Overall, school bans were only significantly associated with reduced prevalence when they were strongly enforced, providing clear evidence for the importance of policy enforcement. While Stephens & English (2002) found that reality often differs from the paper (or spoken) policy, in Wales too, it has been found that smoking policies are poorly enforced in many schools (Stead et al, 1996). More generally, Reistma & Manske (2004) also suggest that variation in strength of policy enforcement across their sample despite a consistency o f policy restrictions due to a province-wide smoke-free school policy indicates that the effectiveness o f local (i.e. school- level) enforcement of policy is a concern.

Crucially, policy enforcement does not only vary between schools, but also

within schools. Perhaps this is connected to the fact that just as there is

variability in policy formality between schools, Darling & Reeder (2003) also found that there was variability in the extent to which sanctions were

documented (formalised) or structured. Perhaps the most blatant example of between-teacher variation is when Reid (1985) states that teachers may turn a blind eye to smoking, describing it as a “relatively trivial offence”. Turner & Gordon (2004b) also identify the fact that staff can undermine policy either by ignoring smoking behaviour, or even actively encouraging it in some cases. Although staff may refuse to intervene when they see pupil smoking for fear o f being physically harmed (Gordon & Turner, 2003a), clearly such behaviour undermines the policy message. Turner & Gordon (2004b) also suggest that policy enforcement is context dependent within schools, with actions (or lack of them) varying depending on: who caught the pupil; that person’s mood; whether the pupil had been caught before; the individual pupil concerned (i.e. nature o f the relationship between pupil and staff member, largely dependent on the staff perception on pupil attitude) and where the pupil had been caught smoking. Stephens & English (2002) suggest that greater effort is needed in training and assisting schools in the importance of compliance and enforcing effective tobacco policies consistent with appropriate guidelines.

There is also evidence to suggest that policy enforcement is not ubiquitous

across many individual school sites. For example, Griesbach et al (2002)

reported that enforcement of both staff and pupil policy varied, with bans on pupil smoking being enforced more often in toilets (48.1% reported always enforced) than in the playground (28.6%) while for staff, bans where much more often enforced when they were in the staff room (75%) than in the playground (20%) - although these data are from a small subgroup o f 20 schools that reported staff smoking bans. Finding that consistent enforcement in both the toilets and outside was clearly associated with a reduction in pupils reporting seeing pupils smoke in these places, confirms the importance of complete enforcement coverage. However, Evans-Whipp et al (2004) have similarly identified that smoking enforcement is difficult in toilets; at sporting events and where smokeless tobacco was being consumed.

Aside from across-site variation of enforcement, another issue touched upon by the literature relates to whether policies are enforced off-site or not. The weight o f evidence clearly suggests that where pupils are allowed off-site

during the day, important challenges are raised regarding the enforcement of school smoking bans (Darling & Reeder, 2003; Gordon & Turner, 2003a; Northrup et al, 1998; Turner & Gordon, 2004a,b). As Darling & Reeder (2003) point out, some schools will limit their enforcement to the school campus, while others will enforce it whenever a pupil is in school uniform. As we shall see, this was an issue of major importance to the success o f smoking policy in Welsh schools. Turner & Gordon (2004a,b) and Gordon & Turner (2003a) highlight the same variation between schools regarding off-school enforcement of policy and argue that neither pupils nor staff in their sample would support a policy that extends beyond the school site and the school hours (Turner & Gordon, 2004a). This confirms Northrup et aV s (1998) assertion that where pupils are allowed off-site during the day, school smoking bans can raise important challenges regarding their enforcement. It is fair to argue, then, that where schools are reluctant to enforce policy off-site, this further enhances the importance o f gating policies in maximising the consistency and effect of school policy. If schools are reluctant to implement such restrictions for pupils during school hours, then consideration needs to be given to spatial and temporal extents o f school authority over pupil smoking behaviour.

While SMT tend to be more active in picking up smoking than non-SMT teachers, the extent to which smoking varies also differs between teachers meaning that picking up smoking is not just dictated by staff authority, but may also be due, in addition to the reasons outlined above, to personal attitudes on smoking; support within the school for staff action on smoking and the staff member’s perception of the role o f the teacher in health promotion (Gordon & Turner, 2003 a). An alternative way o f looking at this is that staff members’ authority over pupils is not created by their rank within the school, but by their relationship with the pupils (Turner & Gordon, 2004a). However, Gordon & Turner also argue that the potential o f support staff (traditionally seen as low rank and authority) to address smoking could be improved by conferring upon them an authority that pupils will respect, by allowing them to invoke sanctions (2003a) thus suggesting that authority is determined by the ability to enforce sanctions when policy is transgressed.

Issues of enforcement are further problematised by Turner & Gordon (2004a) when they argue that schools are not conducive to staff enforcement of smoking policies with the large numbers of pupils dissuading staff from intervening and that pupils may have realised that staff could only influence pupils who were willing to accept staff authority (although interestingly some pupils felt that smoking staff had more right and authority to deal with smoking behaviour as they spoke from an informed perspective). In other words, the success of a sanction depends on the response of die pupil, and a pupil accepting a sanction implies some acceptance o f authority. However, those who smoke, as seen elsewhere, tend to be disenfranchised from school therefore less likely to accept authority. Consequently, sanctions for smokers may be off to a losing start. Staff authority and enforcement is again raised when pupils reported that they were more concerned about their parents’ reaction to them smoking. A higher value was placed on the parent-child relationship and therefore parental reaction was more likely to lead to behaviour change. This is echoed by the work of Wakefield et al (2000) who found smoking bans in the home more effective than school smoking bans at decreasing adolescent smoking. Staff reported the same feeling that parents were better than themselves at influencing pupil smoking behaviour (Gordon & Turner, 2003a). Therefore, for staff enforcement to work, it necessitates a school environment o f respect for staff authority. Indeed, they report that pupils perceived a lack o f teacher authority as impeding their impact on smoking, discovering that pupils felt that teachers enforcing policy, or discussing smoking would be unlikely to impact upon smoking habit, especially where staff are not respected (Turner & Gordon, 2004a). The fact that national Scottish law meant that adolescents were legally allowed to smoke, and that staff had no basis in law from which to act on stopping pupil smoking enhanced these issues. This demonstrates again the need for consistent and integrated policy across all levels of policy-making: policy that does not just devolve responsibility downwards but creates policy which works between and within the levels.