Sample and data collection
Participants for this sustainability study were situated at organizational (i.e. organizations) and individual levels (i.e. citizens). In the prior dissemination and implementation study of '10,000 Steps', 25 public health and sports services department heads reported the extent of project adoption before the first quarter of 2009 [15]. The same group was recontacted 17 months later by email for follow-up responses. After a pre-notification email the organizations received a web link to a code-protected online survey. Three reminder emails within a 5 week period were sent to non-responding organizations. A total of 24 of 25 professional organizations participated in the online survey (96% response rate). Their public service organizations served an approximate total of 531,687 adult citizens.
On the individual level, the 755 respondents of the dissemination and implementation study of '10,000 Steps' [15] were contacted at 14 months follow-up and invited to complete a telephone interview. These respondents were adult citizens living in the work area of the participating professional organizations that had adopted '10,000 Steps' as a whole-community project before the first quarter of 2009. Three attempts were made before recording individuals as "not contactable". A total of 502 citizens completed telephone interviews (66% response rate), 155 were not contactable (21%), 95 were not interested (13%) and 3 were deceased. After excluding ineligible respondents (n = 19, due to events potentially influencing PA levels since the previous time of data collection, such as heart surgery) the final sample consisted of 483 citizens.
All data were collected in the second quarter of 2010. Study protocols were approved by the Ethical Committee of the Ghent University.
Measures
Sustainability measures of '10,000 Steps' in the follow-up organizational survey included 1) project continuation (including sustained implementation of project components and adaptation) and 2) institutionalization in organizations (see Additional file 1). Individual sustainability indicators were established through the telephone interviews and included maintenance of the project's initial effects on individuals' PA [3, 13].
Project continuation
Project continuation was defined as the proportion of organizations that reported continuation of '10,000 Steps' project, in part or in whole, after the prior dissemination and implementation study (Did your organization continue the adoption of '10,000 Steps' the past year?) [9]. Reasons for continuing or declining continuation of the project were also questioned. Additionally, number of staff members, type of organization and working context were questioned to assess representativeness [7].
Sustained implementation of the nine project components
Sustained implementation was measured as the proportion of organizations that continued a specific project or intervention component of '10,000 Steps'. The project components, representing nine socio-ecological components for PA promotion, reflect the key intervention strategies applied in the pilot study in the city of Ghent and the dissemination and implementation study of '10,000 Steps' in the Flanders region [15, 19]. These components include: 1) the sale or loan of pedometers in public places (Did your organization sell or loan pedometers during the implementation of '10,000 Steps'), 2) the use of the '10,000 Steps' website (Did your organization use the supportive website for '10,000 Steps', http://www.10000stappen.be?), 3) repeated dissemination of information using variants of flyers (Did your organization disseminate flyers of '10,000 Steps'?) and 4) posters in public places (Did your organization disseminate posters of '10,000 Steps'?), 5) wide-ranging personal contact with citizens (Did your organization contact citizens in a personalized manner (e.g. personalized letter, mail, or phone)?), 6) the organization of community events (Did your organization stage any community events to promote '10,000 Steps'?), 7) repeated use of the media (Did your organization conduct a media campaign to promote '10,000 Steps'?), 8) the repeated or permanent use of street signs or other strategically placed objects in the street scene (e.g. bill boards) to encourage PA (Did your organization put street signs, billboards, or other promotional materials of '10,000 Steps' in the street scene?) and 9) the initiation of partnerships with local authorities and other associations (Did your organization initiate any partnerships with municipal services, associations or societies to implement '10,000 Steps'?). The median implementation score (score on 100) across all nine components was taken as the global implementation score with methods described earlier [20]. Additional measures included project duration and investment as well as the number of domains of active living or PA domains that was targeted.
Adaptation
Project adaptation was evaluated as the extent to which organizations made changes to '10,000 Steps' from original content or added new project elements during implementation to fit their setting [3] (Did your organization modify any of the inquired project components or add any project elements to '10,000 Steps'? If yes, please specify the additions or modifications).
Institutionalization
Institutionalization or the extent to which'10,000 Steps' was integrated within the culture of organizations through policies and practice [3] was measured using the LoIn scales, developed by Goodman and colleagues [21] and further tested for reliability and validity by Barab and colleagues [22]. The LoIn scales measure 15 aspects of institutionalization related to project production (e.g. written project goals, evaluation), project maintenance (e.g. permanent staff), project support (e.g. permanent funding), and managerial aspects (e.g. supervision). Based on these 15 aspects mean scores for 'routines' and 'niche saturation' scores can be calculated. Routines represent the continued inclusion of the project in the organization's formal plans, allowing them to become routine. The routines score was interpreted as low (≤ 1), low to moderate (> 1 and ≤ 3), moderate to high (> 3 and ≤ 5), and high (> 5). Niche saturation reflects the maximum beneficial expansion of the project within the organization. The saturation score was interpreted as low (≤ 2), moderate (> 2 and ≤ 3), and high (> 3) [21, 22].
Maintenance
To evaluate whether initial effects were sustained on the longer term [7], PA levels were compared between citizens aware of '10,000 Steps' (reached citizens) and those not aware (citizens not reached), as was done in the prior dissemination and implementation study [15]. Citizens' PA levels in a usual week were re-assessed using the telephone-administered long version of the International Physical Activity Questionnaire (IPAQ). This included PA at work, transport related PA, gardening and domestic activities, and leisure time PA. The IPAQ has been proven to be a reliable and valid instrument for assessing PA at the population level in Europe and in Flanders, Belgium [23, 24]. Project awareness was assessed with the following question: Have you heard of '10,000 Steps'? (yes/no) (see Additional file 2).
Data analysis
The proportion of organizations that continued any aspect of '10,000 Steps' as well as which specific components were sustained was calculated. Differences between organizations continuing and not continuing '10,000 Steps' were analyzed with Mann-Whitney U tests and chi-square tests. Descriptive statistics provided information about reasons for (not) continuing '10,000 Steps' (project continuation).
The global implementation score and the implementation scores of each project component were also calculated and converted to z-scores. Comparisons of global and separate project components were made between initial implementation proportions with the follow-up proportions (i.e. comparison of implementation scores over time) using Wilcoxon tests (sustained implementation). Descriptive statistics were used to analyze reasons for not implementing components (sustained implementation) and to obtain insights in any modifications or additions to the project (adaptation).
Chi-square tests assessed differences over time in the proportion of organisations targeting the different PA domains, as well as differences over time in project duration. Wilcoxon tests were used to analyze differences over time in project investment.
LoIn scales were first scored and summed, and mean scores of routines and niche saturation were calculated (institutionalization) [21, 22].
On the individual level, total time for PA in the four PA domains and total time for walking, moderate PA and vigorous PA, all expressed in minutes/week, were computed http://www.ipaq.ki.se at follow-up. Baseline PA levels were compared between drop-outs and respondents using independent samples t tests. Drop-out representativeness was analyzed with independent samples t tests and chi-square tests by comparing both groups on demographic characteristics of gender, age, employment status and educational level. Differences in PA levels between citizens aware and not aware of '10,000 Steps' were analyzed with independent samples t tests. By subtracting mean PA levels of citizens in both groups (citizens aware and not aware) and dividing this score by the pooled standard deviation of PA levels effect sizes for PA were computed. Effect sizes (d) were interpreted as negligible (< 0.15), small (0.15 - 0.40), medium (0.40 - 0.75) or large (> 0.75) [25]. Citizens aware and not aware of '10,000 Steps' were also compared on demographic characteristics using independent samples t tests and chi-square tests.
All analyses were performed in SPSS 15.0 (SPSS, Inc. Chicago, IL) and the level of significance was set at p ≤ 0.05.