Exercise - Symposium

C. Foster and M. Hillsdon
University of Oxford, Oxford, & University College London

Effects of different types of interventions for increasing physical activity behaviour
Purpose: Despite the many benefits of regular health enhancing physical activity (HEPA) too few adults are sufficiently active. This presentation aims to review the evidence of effectiveness of three different types of HEPA intervention, individual, environmental and community based.

Methods: A series of three reviews were conducted using a variety of search methods looking for HEPA interventions aimed at adults aged 16 years or more.

Inclusion criteria for individual HEPA interventions were studies with (1) randomised, controlled designs, (2) comparing different interventions to encourage sedentary, community dwelling adults to become physically active, (3) a minimum of six months follow up from the start of the intervention to the collection of final data and (4) either used an intention to treat analysis or had no more than 20% loss to follow up. Study authors were contacted for additional information where necessary. Standardised mean differences and 95% confidence intervals were calculated for continuous measures of self reported physical activity and cardio-respiratory fitness. For studies with dichotomous outcomes, odds ratios and 95% confidence intervals were calculated.

Inclusion criteria for environmental HEPA interventions were (1) part of observational research using an experimental study design (2) the aim of the study was to examine the effect of changing any aspect of the environment on HEPA behaviour (3) to use a natural or man-made element of the environment as mechanism to increase HEPA behaviour (4) HEPA or physical fitness was the dependent variable (5) the impact of the environmental change was compared against a control, non intervention group or a pre/post measure of HEPA and (6) the study population was over 18 years.

Inclusion criteria for community based HEPA interventions were (1) the community was the 'unit' of intervention (2) the intervention adopted multiple approaches to promoting HEPA. For this review the community was defined as a geographical area, such as a city or town, defined by geopolitical boundaries. This review examined review level evidence.

Results: For individual HEPA interventions sixteen studies involving 6255 participants met the inclusion criteria. Nine studies incorporated a package of behavioural strategies to encourage an increase in self determined physical activity. Strategies typically involved a combination of goal setting, self monitoring, reinforcement, social support and relapse prevention. Seven studies incorporated interventions where the intended physical activity was directed by a health or exercise professional. This review suggests that overall physical activity interventions have a modest effect but due to the heterogeneity of the studies, no conclusions can be drawn about the effectiveness of individual components of the interventions.

For environmental HEPA interventions nineteen intervention studies were found that met the inclusion criteria. The studies divided into two types of environmental interventions. In the first group (of three studies) the environment was physically altered and new opportunities for activity were developed and promoted for the intervention group. In the second group (of sixteen studies) health education materials were used to promote stair climbing in particular environments, commercial or commuting settings. Environmental change studies showed a small increase on HEPA, but the relative impact of environment changes was not evaluated.

For community interventions seven reviews met the inclusion criteria. We identified four common classifications of types of community interventions (1) comprehensive integrated community approaches (2) community-wide 'campaigns' using mass media (3) community-based approaches using person-focused techniques and (4) community approaches to environmental change. The evidence base for the effectiveness of community interventions to promote physical activity is still relatively small. The disparity of approaches makes it difficult to draw strong conclusions about which components of a community approach should be recommended.

Conclusion: Although the evidence base for the effectiveness of the three types of HEPA interventions appears small and inconclusive, some conclusions can be made about effective practice. For individual HEPA interventions, our findings indicate that professional advice and support as well as access to physical activity programmes can encourage people to be more active in the short and mid-term. More research is needed to establish which ways work best in the long term to encourage different types of people to be more active. For environmental HEPA interventions less is known. While some interventions have attempted to change the environment to promote HEPA, the design and numbers of these intervention studies are currently insufficient to make conclusions about what is effective. What is missing is a set of observational studies about the nature of the relationship of the environment to HEPA behaviour. Future research in this area should focus on what aspects of the environment are related to what types of HEPA behaviour for what kinds of people? The review-level evidence for the effectiveness of community HEPA interventions to promote physical activity remains equivocal. While the larger-scale community programmes have had some positive results, they have not tended to demonstrate population-level impact. More positive results have been seen from the smaller-scale programmes which have taken behaviour change techniques more normally used in primary care and translated these to the community setting.

Supported by the British Heart Foundation, London.