MacMillan et al. BMC Public Health 2011, 11:120 http://www.biomedcentral.com/1471-2458/11/120 Firstly, it is a convenient location to reach older adults, as older adults attend their general practice regularly and more often than younger individuals. General prac- titioner (family physician) consultation rates in Scotland increase from the 45-54 year age group upwards [26]. In Scotland, 97% of the population is registered with a gen- eral practitioner/health practitioner [13] and 84% of patients have visited their local general practice team at least once in 2008/2009 [27]. Secondly, the ‘let’s make Scotland more active’ [4] strategy recommended that all patients coming into contact with primary care profes- sionals should be offered counselling for physical activity tailored to individual needs. Thus there is a need to determine practical strategies that such professionals could use. A general practice setting was selected to facilitate future implementation via primary care. This study will explore the use of a non-physician delivery model by employing a practice nurse as the intervention deliverer. Given time constraints on physicians, the use of non-physician delivery models has been recognised as a significant research area [28]. Appropriately trained nurses have been shown to produce equally high quality care as primary care doctors and achieve equally as good health outcomes for patients [29]. In 2008 National Health Service (NHS) Health Scot- land developed a resource (’Energising Lives’ [13]) for primary care staff and other health professionals to ‘pro- vide guidance on how to offer routine advice and encouragement to patients around physical activity’ (p. 5) by including information on the benefits of physi- cal activity and the physical activity recommendations for health. Although there have been various types of engagement across primary care to increase physical activity participation, there is currently no consensus evidence as to what is the best approach to promoting physical activity via primary care settings. Previous phy- sical activity intervention studies delivered via primary care were reviewed by the National Institute for Health and Clinical Excellence (NICE) [30] in 2006. Eleven stu- dies were included in the review, with six studies report- ing significant increases in physical activity. The interventions included brief verbal advice, referrals, and motivational interviews delivered by health promotion specialists or researchers. Two studies delivered brief verbal advice and significantly increased physical activity [31,32]. There are limitations with the evidence from these studies. Specifically, both studies lacked a control condition, were based in New Zealand and Australia rather than the UK, used subjective measures of activity, and used a general practitioner/family physician to deli- ver the intervention (a model unlikely to be adopted in the UK due to constraints on general practitioner time). Of eight UK based studies conducted in primary care since the publication of the NICE guidelines which Page 3 of 12 offered exercise/physical activity support [33-40], only one of these specifically targeted older adults (women aged ≥70 years) [39]) and four included an objective assessment of physical activity [36-39] (although one study used self-reported step counts as opposed to mon- itoring stored counts [37]). Four of the eight studies incorporated a pedometer into their intervention [33,37-39]. The results suggested pedometer use can increase physical activity via primary care, and one study reported a 101% increase in step counts after 12 weeks [37]. From these primary care-based studies it can be summarised that there is a paucity of research conducted in the UK looking at physical activity inter- ventions that: a) target older adults; b) measure physical activity objectively to assess the efficacy of the interven- tions; c) have a graduated pedometer-based walking programme based on the current physical activity recommendations; and d) do not use highly trained members of primary care or researchers to recruit parti- cipants, deliver the intervention and perform follow-up appointments. The West End Walkers study (WEW65+) has been designed as an exploratory trial, as described in phase II of the Medical Research Council’s framework for the eva- luation of complex interventions [41] and as a feasibility and pilot study, as described by the National Institute for Health Research Evaluation [42]. A feasibility/pilot study not only tests (on a smaller level than a main study) the likely efficacy of the intervention (such as the anticipated effect size of the primary outcome) but also tests whether all elements of the planned study can be implemented in practice and work together [42]. Such pilot work, when combined with a feasibility study, also tests intervention characteristics such as anticipated levels of recruitment, how easily the intervention can be implemented by the planned delivery team and whether the intervention is appropriate (e.g. in terms of time commitment, technolo- gical and skills demands, and accessibility) for the target population. The design and appropriateness of the inter- vention and the research protocol and how they impact on these issues (e.g. delivery, recruitment, uptake, reten- tion, calibration, ease of data collection, implications of data for subsequent analysis) are vital for the success of both a pilot study and any subsequent full trial. To ensure that this pilot study took account of prior evi- dence and theory about behaviour change, implementa- tion failures, and engagement in research, a logic model was developed of the initial protocol and this model was used along with key criteria from the RE-AIM framework [43], to strengthen our research plans. A separate paper has been written to describe this process (Blamey A, MacMillan F, Evans A, Fitzsimons C, Mutrie N: Using programme theory to strengthen research protocol and intervention design: A randomised controlled trial of a