Quality of life in bariatric patients up to twelve years after surgery - Results from a nationwide retrospective cohort study.

Background: Bariatric interventions (BI, including surgical interventions) are effective in patients with massive obesity, i.e., a body mass index (BMI) > 40, and their number has steadily increased during the past decade. Yet, the stability of improvements in quality of life (QoL) in post-interventional patients is understudied and restricted to studies with small samples and short follow-ups.

Methods: Patients with BI between 2004 and 2018 were identified in a health claims database and invited to fill in a survey, comprising sociodemographic and lifestyle information and psychometric scales. QoL was assessed with the Bariatric QoL (BQL) scale with lower scores denoting worse QoL. BMI and excess weight loss (EWL) were calculated for the time soon after intervention (EWL-T1) and when filling the survey (EWL-T2).

Results: The majority of n = 2151 patients were female (80.7 %), had a mean age of 54.5 years and a mean BMI of 34.8. The mean EWL-T1 was 79 % (EWL-T2: 64.6 %). The mean BQL score was 47.6 and decreased with BMI (18.5-24.9: 52.6 vs. >40: 38.7), EWL-T2 (>66 %: 51.3 vs. <65 %: 42.1) and years since intervention (3-4: 48.2 vs >8: 45.1, each p < .001). For EWL-T1, the association between higher EWLs and higher BQL scores was stronger in females than in males (p < .005); for EWL at T2, both sexes did not differ in this regard (p = .848). Among normal-weight persons, males scored significantly lower on the BQL than females (44.9 vs. 54.9).

Conclusions: Post-interventional QoL improvements diminish over time and depend on the weight loss, with significant differences between men and women.