Risk factors for multimodal conservative approach failure before bariatric surgery.

Background: A multimodal conservative approach (MCA) is internationally recommended prior to bariatric surgery for the majority of patients. This research aimed to identify risk factors for therapy failure within the MCA.

Methods: This study was conducted in a German bariatric obesity centre. Patients who underwent a 3- to 6-month preoperative MCA from November 2019 to October 2020 were prospectively recorded and analysed. MCA included dietary and movement therapy, psychological and endocrinological referral and connection to a patient support group. The change in BMI was considered the main parameter for therapeutic success. Explanatory factors were evaluated for this outcome of interest and included physical and mental well-being (SF-36), perceived stress (DASS-21), social and economic situation and educational background (SOEP).

Results: Out of 413 eligible patients, 209 were analysed. Overall, patients gained BMI (average gain 0.23 kg/m² (s.d. 1.44 kg/m²)) during the preoperative MCA. Diverse social, demographic and economic and health properties did not influence the course of the therapy. There was a significant positive correlation between successful loss of BMI and physical well-being (β = 0.03, 95% c.i. 0.01 to 0.04, P < 0.0001) and a negative correlation between mental well-being (β = -0.02, 95% c.i. -0.004 to -0.001, P = 0.001) as well as self-perceived stress (β = -0.05, 95% c.i. -0.09 to -0.01, P = 0.019), although these effects were small and did not affect the overall trend of gaining BMI during MCA.

Conclusion: The current therapeutic approach of preoperative conservative treatment within the multimodal concept of bariatric treatment fails to achieve its intended outcome. A different conservative weight loss programme from the pre-bariatric setting, which should focus on a surgical preparation, is therefore recommended.