5.1. PROPUESTA DE MODELO DE AUDITORIA AMBIENTAL, COMO INSTRUMENTO
5.1.3. DESARROLLO DEL MODELO DE AUDITORIA AMBIENTAL
5.1.3.2 ETAPAS DE LA AUDITORIA AMBIENTAL
The process evaluation suggested that some participants were confused about the initiation and maintenance components and also between data collection and delivery of the intervention. They often seemed to perceive that the data collection sessions were part of the intervention and a source of support and there is therefore a need to be aware of a Hawthorne effect, which will influence participant
behaviour and therefore both self-reported and objectively measured primary outcomes. Future research should ensure that clear goals, and the agenda for specific sessions, are discussed and agreed with the participants. When baseline information is required this has a different role (unless part of normative feedback) and should be treated accordingly in the session. Therefore, future interventions should clearly define (and report) the content of the intervention so that aspects such as agenda setting, exploring pros and cons of change and action planning or information exchange are systematic and meaningful.
Because some participants seemed to like the MI approach whereas others seemed to expect or prefer a more didactic approach, future research could investigate the impact of people’s intervention style preferences (i.e. didactic information giving vs. MI) on the effectiveness of a physical activity maintenance intervention. A suitable comparison might be to examine preferred style compared with not preferred style (compared with the control).
There is a clear need to ensure that counselling interventions such as MI are delivered as intended and that the content and approach are accurately reported. Recent studies have explored the potential use of integrating MI and cognitive–behavioural therapy to form physical activity interventions and unless a clear description of the components of interventions are clearly stated it is difficult for practitioners to adapt and embed such approaches when they are shown to be efficacious in research settings. Until studies have demonstrated that an intervention is consistently delivered and internal validity is gained, it is not possible to infer accurately its likely efficacy in increasingly varied contexts.
Our research suggests that correlation between activity questionnaires and accelerometer data is poor (see Chapter 3,Effectiveness of the mini booster intervention compared with the full booster intervention at 3 months, andChapter 4,The prevalence of optimistic self-assessment), a phenomenon that has been noted previously in the peer-reviewed literature.143This might be an indication of social desirability bias, the tendency to answer questions in a fashion that will be viewed positively by others. Social desirability has been found to bias self-reports of diet and physical activity and some research teams recommend methods to measure and control for social desirability bias when self-report questionnaires are used.144,145
InChapter 4(seeThe prevalence of optimistic self-assessment) we reviewed claims of large amounts of moderate to vigorous physical activity when 7-day accelerometry data showed low levels of physical activity across the week. Nicaise and colleagues143make the point that, although low-income Latinas often over-report the amount of moderate to vigorous activity carried out (compared with accelerometry results),
they do substantial amounts of light-intensity activity. Healy and colleagues146have suggested that light-intensity physical activity is associated with improved glycaemic control that is independent of the amount of moderate and vigorous physical activity carried out. Researchers and policy-makers may need to adjust unreasonable expectations of those who are constrained by motivational, physical, social or
environmental factors; for such people, reducing sedentary behaviour and increasing low-intensity activity may be both appropriate and clinically important.
Chapter 9
Conclusions
A
lthough some individuals dofind a community-based, brief MI‘booster’intervention supportive, the low levels of recruitment and retention in this trial and the lack of impact on objectively measured physical activity levels in those with adequate outcome data suggest that it is unlikely to represent a clinically effective or cost-effective intervention for the maintenance of recently acquired physical activity increases in deprived, middle-aged, urban populations.The gap between the size of the sedentary population who could achieve significant long-term health benefits from relatively small but sustained increases in physical activity levels and the numbers taking up the offers of both the initial brief intervention and the subsequent‘booster’interventions suggests that this type of MI-based approach will be appropriate only for a minority of the sedentary population who could, in principle, benefit from being more physically active. Other approaches that require less proactive (and potentially time-consuming) engagement from individuals, including environmental interventions to encourage active travel and recreational activity, may be particularly important for deprived communities and middle-aged populations who are less likely to prioritise their own physicalfitness and well-being over other demands on their time and resources.
Many types of physical activity interventions can exacerbate health inequalities because they are more likely to be taken up, and subsequent behaviour change achieved and maintained, by those who are already active and those in better health. The booster study was therefore explicitly designed to target recruitment in communities that were known to have poorer health outcomes. The lessons learnt in undertaking this trial should inform both the design of future physical activity intervention trials and the development of more effective interventions that not only are feasible and affordable but also will have sufficient reach to have an impact in the most deprived and most sedentary populations who could benefit most from sustained increases in their physical activity levels.