Discussion
This review examined literature published between June 2007 and January 2015 on interventions to improve GMS in young children (0–5 years). Seven studies were included and 86% found evidence that interventions are successful. Since developing GMS has been recommended as part of national physical activity guidelines for this age group in three countries (which have all been released since the original review),24–26 it is interesting that only seven interventions have been reported in the past 8 years. Reasons for a limited implementation of programmes to develop GMS could be: a lack of funding or interest in this area, the complexity of implementing programmes in childcare settings, or a lack of competence and confidence in setting staff.
Implementation
All studies were implemented in early childhood settings. This setting is popular for group RCTs because it is relatively easy to randomise at a whole centre level, and programmes can be incorporated into regular routines. Furthermore, it maximises the number of staff involved and the responsibility of implementation can be shared. Compared to the previous review, the number of RCTs has increased from 29% to 86%, which is positive given that RCTs are the ‘gold standard’ in research design.
Setting staff delivered the intervention in six studies and training was offered to increase their competence and confidence in delivering the programme and to enhance professional development.17–19 ,20 ,21 ,23 This training varied from a 1 day workshop17 ,23 to several separate workshops spread over different days.19 ,20 Professional development of staff is important to enhance their self-efficacy in delivering a programme and to provide them with up-to-date information on the importance of GMS and how to teach them. Especially in young children it is important to enhance their motivation and involvement through people that have experience, are competent and confident. Other advantages of setting staff delivering the intervention have been mentioned in the previous systematic review12 and include maximising the potential sustainability of the programme and minimising costs associated with implementation.
As recommended by Riethmuller et al12 parents should play an important role in developing GMS through role modelling and providing opportunities, encouragement and support.12 ,24 However, only two studies involved parents. This was done through home connection materials such as educational handouts and a music CD18 or parent information sessions to inform them on the benefits of physical activity and how to integrate this within their family environment.19 It is recommended to actively involve parents in centre-based GMS development programmes and encourage them to practice skills in the home environment12 to reinforce the learning that has occurred at the centre and strengthen the relationship between the centre and home setting. Informing and guiding parents in how to practice GMS, the duration of practice and how to motivate their children can be done in several ways such as through information sessions, by handing out home materials or via email and the use of social media.
While only seven studies were identified, the sample sizes, duration and programme content varied widely. Most studies included in this review recruited whole childcare centres, which helps to maximise sample size.
The duration of the programmes varied between 2 and 10 months. Four programmes lasted ≥20 weeks,18 ,20 ,22 ,23 an increase compared with the average of 12 weeks in the previous review. Intervention sessions were delivered between two and five times a week and the average duration of the intervention sessions was around 20 min. On average this gives a greater intervention ‘dose’ compared to the studies in the previous review where there was approximately 1 h of instruction per week. Based on this current evidence it seems that a higher intervention ‘dose’ with at least two sessions a week may contribute to the effectiveness of interventions.
Efficacy
Six studies found significant intervention effects.17 ,18 ,20–23 Even though Bonvin et al19 had high methodological quality, they did not collect any data on the exact amount of daily physical activity time or the use of any specific curriculum, which means the intensity might have been inadequate and there was no control on what activities were done.
Not all studies clearly described their intervention programme which makes it difficult to compare intervention components. Therefore, no key components could be identified that would contribute to a successful intervention.
Methodological quality
Four included articles had high methodological quality. Compared to the review of Riethmuller et al,12 the percentage has increased from <20% to 57%, and the high number of RCTs might have contributed to this. Power calculations have been recommended to ensure that appropriate statistical analyses could be performed.14 However, only two studies conducted a power calculation.19 ,23 A reason why two other included studies did not perform power calculations could be because they were pilot studies and therefore not adequately powered to detect statistical significances.17 ,20 For future studies, however, it is important to conduct power calculations in order to appropriately test the effectiveness of these GMS development programmes in young children.
Strengths and limitations
This review has a number of strengths. These include searching multiple databases, extraction of extensive study details from the articles, methodological quality assessments with high agreement levels and alignment with the PRISMA statement.14 Limitations include the following: the effectiveness of interventions could not be compared because of different instruments that were used to assess GMS, only a small number of updated studies were found, and studies had to be published in English.
Recommendations
Development of GMS in young children is important. When given the opportunity and encouragement to learn and practice GMS, children are able to master these skills before the end of childhood.27 The recommendations made in the previous review are still important:12 utilising a partnership approach in which researchers and childcare staff work together to share responsibilities, minimise the burden and support each other; programme facilitators should be chosen carefully because their competence, confidence and enthusiasm influences children's participation; parents should be involved; conducting sample size calculations to ensure appropriate statistical analysis; and improving the methodological quality of interventions (alignment with the CONSORT or TREND statement).Additionally, the following recommendations can be made:
More high-quality GMS interventions are needed based on the current evidence of relationships between GMS development and other developmental areas and extra funding should be provided to support the development of these interventions.
Intervention components should be clearly described in order to compare the different intervention programmes and determine which components contributed to the effectiveness of the intervention. For future research, this is important in order to implement the most optimal intervention programme.
Based on the current evidence it seems that a higher intervention ‘dose’ with at least two sessions a week may contribute to the effectiveness of interventions.
Consistency in GMS assessment is important to compare results between interventions and conduct meta-analysis.