This study has demonstrated that this novel intervention was feasible and acceptable to disadvantaged families to help them to reduce their children’s exposure to SHS at home.
Qualitative findings highlighted that personalised feedback of children’s levels of SHS appeared to motivate behavioural change and that home air quality feedback was the more reliable and acceptable method for doing this.
All participants appreciated the behavioural support component of the intervention with some showing particular appreciation for the non-judgemental manner in which it was delivered. The literature suggests that increasing the intensity of home-based interventions can increase their effectiveness [13]. The intervention was made more intensive in phase 2 by adding proactive telephone support and increasing the frequency of home visits in the earlier stages of the intervention. It is possible that the intensive nature of the intervention and the regular, personalised behavioural support encouraged strong relationships to be built and therefore contributed to the good retention of study participants. The changes to the structure of the intervention for phase 2 were also made to try and aid the transition to independence for participants by making visits less frequent towards the end of the intervention attempting to encourage participants to maintain changes on their own.
All participants not contraindicated accepted the initial offer of NRT for temporary abstinence but some expressed negative views mainly around the side effects, such as taste, which have been reported in other studies [16]. However, other participants suggested that they may go on to use NRT for a quit attempt in the future, possibly as a result of their positive experience of using NRT to temporarily abstain from smoking in the home and so it is important that NRT is included as part of the intervention in an exploratory efficacy trial.
Providing feedback via children’s cotinine whilst acceptable and feasible (for saliva) proved to be problematic. Results were variable, often not consistent with corresponding urine cotinine results, and did not reflect the home smoking behaviour changes self-reported by the participants. Ultimately, this variability had a detrimental effect on caregivers’ motivations to maintain any changes to home smoking behaviours. A further limitation of cotinine feedback is that it does not relate exclusively to SHS exposure in the index household as levels can be impacted by SHS exposures from other environments (such as if the child spends considerable time in a grandparent’s home where smoking was unrestricted). This issue limits the effectiveness of saliva cotinine feedback as an outcome measure for SFH interventions and as a motivator for sustainable behaviour change.
In an attempt to overcome the issues with cotinine, home air quality data (PM2.5) were used to provide personalised feedback in phase 2. The graphical presentation of results was well received and understood, supporting findings from previous research which shows that smoking caregivers are able to understand complex data presented to them in this manner and that this type of feedback is acceptable and motivating to caregivers [14]. It appears that the use of longitudinal air quality data helped to motivate caregivers to initiate and maintain changes to their home smoking behaviours. By providing feedback on three occasions over the 12-week intervention period, the participants were able to see the positive effects that their behavioural changes had on home air quality. There were however some potential issues with using home air quality, for example, monitors were placed in one specific location within a household and we were therefore unable to accurately indicate air quality levels in other areas of the house, although this location was identified as the place where the child spent the most amount of time during the day. It is also possible that participating families could change their smoking behaviour inside the house for the period of time that the monitor was present [14] although the participants reported that they often forgot that the monitor was there and so it is unlikely that this would have significantly influence the results. Finally, it is important to highlight that whilst we have used the term SHS exposure throughout this manuscript, PM2.5 is a proxy measure of personal exposure and an indirect measure of SHS that is not specific to cigarette smoking as results can be influenced by any airborne particles 2.5 ?m in size.
The findings from the current study help to build on the results of the REFRESH intervention feasibility study [14, 24], although REFRESH did not offer caregivers NRT, only provided home air quality feedback on two occasions (compared to three in the current study) and the intervention period was significantly shorter (4 vs. 12 weeks). The REFRESH results showed a statistically significant decrease in maximum PM2.5 between weeks 2 and 4 within the intervention group but no significant difference between the intervention and comparator arm [14]. Since the evidence base suggests that intensive and sustained contact is more likely to be successful in helping smoking caregivers to make changes [13], we might expect our intervention to be more effective. This is supported by the feasibility data which showed an average decrease of 49 % between baseline and week 12 in average PM2.5 and a 74 % reduction in the maximum PM2.5.
Recruitment proved labour intensive with a total of 65 Sure Start Children’s Centre sessions being attended in order to recruit 14 participants. Only a small minority (7 %) of the caregivers approached met the inclusion criteria during the initial recruitment discussion about the study. This is lower than we had anticipated given the relatively high smoking rates of caregivers accessing CCs [17] and that 39 % of children living with smokers in England are reportedly exposed to SHS at home [6]. However, it may reflect the nature of recruitment in CCs (sometimes in a public environment where the discussion could be overheard) and the potential stigma attached to smoking in the home with young children. The caregivers may therefore have been smoking at home but not willing to share this information with the CC staff and/or research team and thus would be deemed ineligible. In addition, we know that rules about smoking at home are often fluid and that whilst caregivers may initially state that they always smoke outside, it is only with further exploration of home smoking rules that it becomes apparent that caregivers sometimes smoke inside [17]. To try and overcome this in the explanatory RCT, a number of additional recruitment strategies will be employed (including, for example, via health visitor mail shots, outreach services, advertising, the local stop smoking SFHs service) and more care taken to ensure that recruitment discussions are conducted more privately where possible. Having said this, nearly half of eligible participants took part in the study and 12 of the 14 participating families completed the intervention. This suggests that a proportion of smoking caregivers are interested in making changes to their home smoking behaviours and that the home setting, length and delivery of the intervention were acceptable to them.