Preferences of women in difficult life situations for a physical activity programme: protocol of a discrete choice experiment in the German NU-BIG project

Introduction The BIG project (‘Bewegung als Investition in die Gesundheit’, ie, ‘Movement as Investment in Health’) was developed in 2005 as a community-based participatory research programme to offer accessible opportunities for physical activity to women in difficult life situations. Since then, the programme has been expanded to eight sites in Germany. A systematic evaluation of BIG is currently being conducted. As part of this effort, we strive to understand the preferences of participating women for different aspects of the programme, and to analyse their willingness to pay. Methods and analysis In this protocol, we describe the development and analysis plan of a discrete choice experiment (DCE) to investigate participants’ preferences for a physical activity programme for women in difficult life situations. The experiment will be embedded in a questionnaire covering several aspects of participation in the programme (eg, reach, efficacy and further effects) and the socioeconomic characteristics of all active participants. After a thorough search of the literature, BIG documents review and expert interviews, we identified five important attributes of the programme: course times, travel time to the course venue, additional social activities organised by BIG, consideration of wishes and interests for the further planning of courses and costs per course unit. Thereafter, we piloted the experiment with a sample of participants from the target group. After data collection, the experiment will be analysed using a conditional logit model and a latent class analysis to assess eventual heterogeneity in preferences. Ethics and dissemination Understanding women’s preferences will provide useful insights for the further development of the programme and ultimately increase participation and retention. The questionnaire, the included DCE and the pretest on participants received ethical approval (application no. 20-247_1-B). We plan to disseminate the results of the DCE in peer-reviewed journals, national conferences and among participants and programme coordinators and organisers.


Appendix 1: course description in each BIG-site
The two search phrases in gray did not lead to any result. BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s)

General overview of the retrieved studies
The search led to 18 studies and one protocol of one of the studies (Pinto et al., 2017). Two studies (Veldwijk et al., 2013;Veldwijk et al., 2014) used the same DCE, so we will refer to only one of them for simplicity. The studies focused on different topics but were all concerned in deploying DCE techniques to understand preferences for a physical activity intervention (sometimes labeled as "lifestyle intervention", including also diet). They dealt with the following topics: -Lifestyle intervention for: o Diabetes prevention (Owen et al., 2010) o Stroke survivors (Geidl et al., 2018) o Knee osteoarthritis (Pinto et al., 2017;Pinto et al., 2019) [Study + Protocol] o Parkinson´s disease (Paul et al., 2021) o Diabetes patients (Salampessy et al., 2015;Sommer et al., 2020;Veldwijk et al., 2014, Veldwijk et al., 2013, Ramirez & Beale, 2016van Gils et al., 2011) [two studies by Veldwijk using the same DCE] o Older adults (Brown, 2009) -Focus on outcomes of health promotion interventions (Alayli-Goebbels, 2013) -Focus on goals of health promotion interventions (Benning, 2020) -Focus on financial incentives for physical activity (Farooqui, 2014;Giles, 2016;Molema, 2019, Wanders, 2014, Matsushita, 2017 136 studies identified 26 studies selected (based on title screening) 110 studies considered not relevant 19 studies -16 unique studies -1 protocol -2 studies used the same DCE (Veldwijk et al., 2014;Veldwijk et al., 2013) 7 studies excluded: -3 studies investigating preferences for general physical activities in patients (no intervention) (Abogaye et al., 2017;Abogaye, 2017;Ferreira et al., 2020) -1 study investigating general lifestyle advice (Robles et al, 2020) -1 protocol for a systematic review (Dintsios et al., 2018) -2 studies investigating preferences for interventions with a different focus (weight loss, cardiac rehabilitation) (Kjaer et al., 2006;Ryan et al., 2015) BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s) BMJ Open doi: 10.1136/bmjopen-2022-067235 :e067235.

Systematic extraction of attributes and levels
We collected all attributes and levels from the selected studies. We eliminated those who were specific of the context analyzed and not transferrable to our context (diet related items, items related to a specific disease). Furthermore, we excluded those that were potentially relevant for a general physical activity intervention but were not applicable to our context (mixed groups including men, exercising alone/at home, schedule and goal setting by coach/physician, monetary interventions, goal setting, consultations with coach or physician, etc.). The remaining attributes are presented in Table A Some of the exercise is supervised None of the exercise is supervised Other other information provided no other information Giles et al., 2016 written leaflet on benefits of activity and ways to be more active face-to-face discussions on benefits of activity and ways to be more active written leaflet and face-to-face idscussion on benefits of activity and ways to be more active BMJ Publishing Group Limited (BMJ) disclaims all liability and responsibility arising from any reliance Supplemental material placed on this supplemental material which has been supplied by the author(s)

Appendix 3: further definition of attributes and levels based on experts feedback
In the meeting with the expert, 10 attributes were presented: -Price per course unit -Course times -Travel time to hall/course -Additional social activities -Additional course content -Participation in organization -Course registration -Group composition -Presence of childcare -Course duration (in minutes) The discussion led to a reformulation of two attributes and the identification of an additional one. The additional attribute identified was "flexible intensity of the course" (i.e. if the intensity of the exercises within a course could be flexibly adjusted or not). The two attributes that were reformulated were: -"course registration" (i.e. if all costs for the whole course must be paid in advance or if each appointment can be paid separately) was substituted by the attribute "trial lecture" (i.e. if a trial lecture is offered or not). -"group composition" (i.e. women from the same social background/migration background vs mixed group) was substituted by an attribute specifically targeting respect of religious standards (i.e. framework: the hall is visible from the outside or not).
Based on the insights gained during the consultation with the experts, we performed a selection of those attributes which respected the following characteristics: -Relevant for the overall utility -Influenceable -Close to reality (in the BIG program) -Substitutive relation -No dominance Based on the insights from the experts we considered presence of childcare and presence of trial lessons as dominant criteria for the decision. These attributes, together with the presence of a female coach were considered as fix characteristics for the DCE.
According to the experts, the attribute "course duration (in minutes)" was distributed between 60 and 90 minutes for almost all offered courses. Given the limited variation, we decided to discard this attribute and fix it at 60 Minutes along the previously mentioned course characteristics.
The attribute "course registration" (paying everything at the beginning or paying each lesson at a time) was perceived as not relevant by the experts. Therefore we decided to exclude this attribute altogether.
The attribute "flexible intensity (yes or no)" was also deemed unimportant for the present DCE, since basically in all courses offered the intensity can be flexibly adjusted. Women also have the possibility of visiting a trial lesson and receive individual advice regarding their fitness level. This information will be included also in the fix course components.
The attribute "framework (hall is visible from the outside yes or no)" was deemed as a dominant criterion for some women (especially Muslim women) and not relevant for some other women. In both cases the attribute should not be included in the DCE. We therefore decided to fix this attribute as well.
The remaining attributes were included in the DCE. These are: The attributes "additional social activities" and "additional course content" were merged into one attribute for the following reasons: -The attribute additional course content was not clearly formulated and led experts to different interpretations/questions of what it means (e.g. additional lectures or additional content in the same appointment as the sport course? Etc.) -At the moment in most BIG courses additional social activities include also the informal exchange on other topics (healthy diet, mental health, integration, help with translations,…) so that the two additional activities (social and content) largely overlap at the moment The final attributes and levels included are (original language):
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