Mixed methods investigation of the public health impact of pre-surgical health optimisation interventions in elective arthroplasty

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)


Commissioning policies in some areas of England influence National Health Service patients’ access to hip and knee replacement surgery based on their body mass index. Delay or denial of surgery is intended to promote weight loss as part of ‘health optimisation’. This thesis comprises four studies which investigate the impact of these restrictive policies.

A descriptive study of National Health Service body mass index policies for access to hip and knee replacement revealed high and rising use of restrictive policies, with variability by geography and content. In 2021, 67.9% (72/106) of commissioning groups in England had body mass index policies, 66.7% of which were restrictive.
Use of interrupted time series analysis in a natural experimental study demonstrated an association between policy introduction and a reduction in surgical provision. Patients of lower socio-economic status were disproportionately affected, likely due in part to lower use of independently-funded surgery.

A qualitative study of key informants in policy decision-making and implementation for health optimisation demonstrated that short-term financial pressures were key drivers in the use of restrictive policies. Participants highlighted strong concerns about using body mass index for rationing, inadequate provision of weight management services, and exacerbating health inequalities.

A scoping review of available health economic models for valuing obesity reduction from behavioural interventions identified 44 models, 32 of which had been used only once. Only four models complied with existing expert recommendations, limiting decision-makers’ ability to justify the development and implementation of weight management services needed for equitable health optimisation.

The thesis concludes that restrictive policies should no longer be used to limit access to surgery, but that future research and practice developments can strengthen alternative approaches. Shared decision-making and equitable provision of integrated support for health improvement during the surgical pathway could contribute as one element of wider policies to address obesity.
Date of Award19 Mar 2024
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorAndy Judge (Supervisor), Hugh S T McLeod (Supervisor), Amanda L Owen-Smith (Supervisor) & Ruth R Kipping (Supervisor)


  • Obesity
  • policy making
  • Surgery
  • Public Health
  • Health inequalities
  • body mass index
  • health optimisation
  • Health Economics

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