## 2 Materials and Methods
### Detailed Presentations of the Methodological Steps of the DYNAMIKOS Model
#### 2.1.1 Development of the Casual Loop Diagram via Group Modeling Building Methodology (Phase A)  
In this phase, the methodology of Group Modeling Building (GMB) will be applied to formulate a CLD of risk factors for KOA based on the dynamic hypothesis of the complexity of knee OA. The procedure includes, at first, an extensive literature review that will be performed to evaluate current approaches, identify risk factors, and collect valuable historical data regarding KOA. Keywords such as \"Knee and osteoarthritis and risk factors\" will be used for the literature search in PubMed, Scopus, and Web of Science databases. Systematic reviews and meta-analysis, cohort studies (retrospectives and prospectives), and randomized controlled trials will be included in the literature review that assess the effect of various risk factors on the development of KOA. Subsequently, a series of co-creation GMB workshops will be set up where the modeling team and stakeholders will collaborate and conduct a comprehensive analysis of the KOA issue. A panel of experts in KOA and stakeholders (orthopedic surgeons working in hospitals, clinical physiotherapists, medical staff, KOA patients, and a member who is an expert in SD modeling) will be involved in the process of co-creating the CLD model to support the implementation of the procedure. This group's operation will guide the successful development of the CLD for KOA risk factors. Further interviews with stakeholders will be conducted where and when necessary. During the workshops, specific scripts will be utilized for the appropriate GMB methodology. Scripts constitute structural small group exercises taking place during the workshops that determine the group's behavior by providing an organizing framework for the activities of GMB. Such activities [25] include stakeholder mapping, group member articulation of their \"hopes and fears\" for the DYNAMIKOS model, exercises to draw out reference modes of the variables that affect the problem, and various approaches to  
Figure 2: Phases of DYNAMIKOS model development. Abbreviations: KOA—Knee Osteoarthritis. capture the structure of the KOA. Each script session has a specific structure and includes elements about the script's scope, the time a script should be considered, materials needed, etc. The total GMB workshop is a coordinated process in that each script is integrated into a dynamic plan [25]. The guidelines of Scriptapedia and ScriptMap will be used [25; 26]. The main scripts that will be used in the GMB process are presented in Table 1.  
During the co-creation workshops, each of the members of the DYNAMIKOS project team should serve one or more of the roles below: (1) the facilitator, who is the team guide; (2) the modeler/reflector, whose focus is on the DYNAMIKOS model created for the team; (3) the process coach, who mainly considers the dynamics among the members and subgroups of the team; (4) the recorder, whose action is mainly to record the main elements that arise for the team progress; and (5) the gatekeeper, typically a policymaker from the community pertinent to the issue under consideration [24; 25]. In the last part of phase A, the development of the CLD and the DYNAMIKOS model will be initiated. A hypothesized CLD model of interrelationships among factors is presented in Figure 3, illustrating that specific dynamic interrelations among KOA risk factors contribute to knee OA. The CLD in Figure 3 highlights the system's variables and the link polarities between the variables, differentiating between positive and negative feedback loops [22; 25; 27]. The Vensim (Ventana systems, version 10.2.1) software package will be employed for the SD model development.