MacMillan et al. BMC Public Health 2011, 11:120 http://www.biomedcentral.com/1471-2458/11/120 wear the pedometer at all times apart from when washing and sleeping. The NL-1000 threshold for moderate-to-vig- orous intensity was set at Level 3, corresponding to walking activity above 2.9 METs [55]. ii) Activity patterns The activPAL monitor (PAL technologies Ltd, Glasgow, Scotland) was used to assess activity in more detail. The activPAL is a small (5 × 3.5 × 0.7 cm), light (20 g) unit which is attached to the anterior surface of the thigh, approximately midway between the inguinal crease and the proximal border of the patella. The monitor mea- sures many variables including total time and percentage of time spent seated/lying, standing and walking, the duration of these events, number of steps per day and during each walking period and the cadence of walking periods. A detailed breakdown of the patterns of daily activity is given by the activPAL as events and periods of time spent in particular postures are time stamped. Data were recorded in 15-second epochs. The activPAL has a battery life of around 9 days and was worn con- tinuously during this period (providing 8 full days of data). The monitor has previously been validated for use with an older population [56]. Physical activity and patterns of physical activity were measured at baseline, between 11 and 12 weeks and between 23 and 24 weeks in both groups over a period of 7-12 days (figure 1). At baseline pedometers were sealed using tape for both groups and at 11 weeks for the delayed group so that participants were not aware of their step counts. After the initial consultation (visit 2 for the immediate group and visit 4 for the delayed group) participants were given an unsealed pedometer. Pedometer and activPAL data collected between visits 1 and 2 gave a baseline reading of physical activity partici- pation for both groups. Between visits 3 and 4 for the immediate group and between visits 5 and 6 for the delayed group, pedometer and activPAL data gave a measure of physical activity participation 12 weeks after the initial consultation. When physical activity was assessed between visits 5 and 6 for the immediate group this gave a measure of participation 12 weeks after the second consultation (i.e. 24 weeks after the initial con- sultation). Physical activity behaviour was also assessed subjectively using the Stage of Change question [48] at baseline and again at 24 weeks in both groups. ii) Well-being To determine the efficacy of physical activity interven- tions for older adults it is important to assess the effects of interventions on the specific areas of health that are important to older adults (e.g. functional capacity, well- being and social interaction). These areas were assessed using the following self-report questionnaires: the Posi- tive and Negative Affect Schedule (PANAS) to assess Page 8 of 12 mood [57]; the Short-Form (36) Health Survey version 2 (SF-36v2) questionnaire which measures quality of life [58]; the Perceived Motor-Efficacy Scale for Older Adults (PMES-OA) to assess functional ability [59]; and the UCLA Loneliness Scale (version 3) [60] as a measure of emotional and social loneliness. Questionnaires were completed by both groups at visits 1, 4 and 6. In addi- tion to these questionnaires, at visit 1 participants com- pleted a demographic questionnaire. iii) Qualitative study To gain an insight into participants’ experiences of the walking intervention, two focus groups were conducted; one with the immediate group, the other with the delayed group (on completion of the 12-week programme). Focus groups are an established method for accessing personal experiences and for facilitating more in-depth under- standings of participants’ views [61]. All focus groups were facilitated by two members of the research team. Each group consisted of seven to nine participants and lasted for approximately an hour. Questions posed exam- ined both positive and negative experiences. Specifically, the focus group schedule explored perceived benefits of increased walking, views on the pedometer, the physical activity consultation and on-going support, problems encountered, future recommendations and reflections on participation. Focus groups were audio-recorded, tran- scribed verbatim and thematically analysed (see below). These data, when combined with demographic and effi- cacy data, will provide insight into the mediators and moderators of change in walking behaviour. In addition, semi-structured interviews were conducted with key members of the research team, in order to explore their experiences of implementing the intervention. The inter- view schedule covered key questions about the feasibility of implementing the intervention into current care and other settings (including acceptability of intervention training to current general practice staff) and ways of improving the intervention for future delivery. The quali- tative evaluation of the intervention supplements the experimental phase by providing context-rich, in-depth information on participants’ experiences and provides an insight into the underlying processes that determine the feasibility of the intervention, for instance, what worked, what did not work, the perceived impact and why and how the intervention could be improved for future delivery. Setting Visits were conducted either at a general practice in the West End of Glasgow or in the Glasgow Clinical Research Facility at the Western Infirmary, Glasgow (http://www. glasgowcrf.org.uk). Focus groups were conducted in a uni- versity building or a suitable community venue.