Adipositas Care and Health Therapy (ACHT) after Bariatric-Metabolic Surgery: A Prospective, Non-Randomized Intervention Study

Introduction: Almost 25% of German adults have obesity and numbers are rising, making it an important health issue. Bariatric-metabolic surgery reduces body weight and complications for persons with obesity, but therapeutic success requires long-term postoperative care. Since no German standards for follow-up by family physicians exist, follow-up is provided by surgical obesity centers, but they are reaching their limits. The ACHT study, funded by the German Innovation Fund, is designed to establish and evaluate the follow-up program, with local physicians following patients supported remotely by obesity centers. Methods: ACHT is a multicenter, prospective, nonrandomized control group study. The 18-month ACHT follow-up program is a digitally supported, structured, crosssectoral, and close-to-home programto improve success after bariatric-metabolic surgery. Four groups are compared: intervention group 1 starts the program immediately (3 weeks) after Roux-en-Y gastric bypass or sleeve gastrectomy (months 1-18 postoperatively), intervention group 2 begins the program 18 months after surgery (months 19-36 postoperatively). Intervention groups are compared to respective control groups that had surgery 18 and 36 months previously. In total, 250 patients, enrolled in the intervention groups, are compared with 360 patients in the control groups, who only receive standard care. Results: The primary endpoint to compare intervention and control groups is the adapted King's score, a composite tool evaluating physical, psychological, socioeconomic, and functional health status. Secondary endpoints include changes in care structures and care processes for the intervention groups. Multivariate regression analyses adjusting for confounders (including the type of surgery) are used to compare intervention and control groups and evaluate determinants in longitudinal analyses. The effect of the intervention on healthcare costs will be evaluated based on health insurance billing data of patients who had bariatric-metabolic surgery in the 3 years prior to the start of the study and of patients who undergo bariatric-metabolic surgery during the study period. Conclusions: ACHT will be the one of the first evaluated structured, close-to-home follow-up programs for bariatric surgery in Germany. It will evaluate the effectiveness of the implemented program regarding improvements in health status, mental health, quality of life, and the feasibility of such a program outside of specialized obesity centers.