PRE-WELL: Does PRE-operative WEight Loss improve surgical outcomes and Long-term behaviour change?

Research question Does the pre-operative period act as a teachable moment for promoting weight loss to improve surgical outcomes and long-term behaviour change? Background There are growing surgery waiting lists with seven million people in the UK waiting for elective care.

Approximately 30% of people are living with obesity, which is a risk factor for many health conditions that require surgery and costs the NHS £6.1 billion/year. Helping patients lose weight pre-operatively may improve health outcomes. However, there is a lack of evidence (three trials all using very low-calorie diets).

It is unknown whether weight loss improves surgical outcomes, if it differs by surgery type, if interventions are equitable (access and effectiveness) and whether they result in long-term weight management.

Aim To examine whether pre-operative weight loss support within NHS pathways improves surgical outcomes and long-term behaviour change.

Objectives To determine: If pre-operative weight loss improves surgical outcomes and long-term weight change (over five years). What support patients want to lose weight. If offering pre-operative weight loss programmes is feasible. If pre-operative weight loss programmes are effective and the effective components.

I will explore this by health inequalities (deprivation and ethnicity) and type of surgery.

Methods WP1: An observational study to examine the association between weight loss, elective surgical outcomes, and long-term weight change (months 1-13) Using Clinical Practice Research Data (CPRD), linked hospital episode statistics (HES) and mortality data, I will examine the association of weight change pre-operatively (in patients living with obesity from diverse backgrounds) with surgical outcomes and weight change over five years.

WP2: Qualitative interviews and co-production of pre-operative weight management programmes (months 1-13) Individual semi-structured interviews with diverse stakeholders about which weight management programmes would be acceptable and feasible.

I will deliver a co-production workshop with stakeholders to share interview findings and decide on pathways and programmes.

WP3: A feasibility RCT of a weight management programme prior to surgery (months 11-48) A multi-centre feasibility RCT (n=120) to examine if it is feasible and acceptable to offer weight management programmes prior to surgery. Participants will be referred to a weight management programme decided in WP2.

WP4: An individual participant data (IPD) meta-analysis and evaluation of real-world data to examine the effect of support to lose weight prior to surgery (months 46-58) I will examine the effectiveness of pre-operative weight loss interventions on surgical and patient outcomes using RCTs and data sets from NHS services.

Dissemination Outputs will be co-developed with our diverse PPIE group and include website/social media, blogs, international presentations/meetings, and >7 academic papers.

The main output will be an intervention and collaborations that will (if feasible) lead to a funding application for an effectiveness trial, furthering my development to becoming an international leader.

NHS/Patient impact Improved care for patients living with obesity and improved surgery outcomes by reducing operative risks. Efficiency savings through reduced length of stay in hospital after surgery.

Career impact Support my transition to being an internationally prominent research leader in my field and steps towards a professorship.