Barriers and facilitators for consuming a plant-based diet in patients with knee osteoarthritis: a qualitative study.

Introduction: A predominantly plant-based dietary concept was developed in the course of the NUMOQUA study (Nutrition and Movement to Improve Quality of Life in Patients with Knee Osteoarthritis) as part of the interdisciplinary therapeutic intervention for patients with knee osteoarthritis (OA). This study included focus group discussions (FGDs), which aimed to identify perceived barriers and facilitators for following these dietary recommendations. Methods: In total, 4 FGDs were held with a total of 24 participants aged 50-75 years with mild to moderate knee OA, who belonged to the intervention group of the NUMOQUA study and followed the plant-based diet. FGDs were recorded, transcribed, and coded using an adapted version of the socio-ecological framework in MAXQDA (Max Qualitative Data Analysis) software. Thematic areas were identified by collating data relevant to each code, code group, and the four spheres of influence (individual, interpersonal and social, environmental, and policy). Results: Barriers for adopting the dietary recommendations primarily involved the limited availability of suitable options when eating out, adherence to traditional eating habits, and prioritizing family members' preferences. Facilitators included family support, goal-setting, establishing a routine, individual approaches, and motivation derived from improved physical health. Discussion: The results reflect the diversity of influencing factors at the individual, interpersonal and social, and environmental levels, and provide important information for future dietary interventions for those affected by knee OA and other non-communicable diseases, particularly as cardiovascular diseases and type 2 diabetes. Clinical trial registration: https://clinicaltrials.gov/study/NCT05955300, identifier NCT05955300.