Parts of this chapter have been reproduced, with permission, from Grieve et al.67
Introduction
With bariatric surgery care pathways known to vary considerably, the first step in obtaining better evidence of what works is to establish what is currently delivered. To this end, a survey of NHS-funded SCOTS study sites was undertaken in order to describe current services, to estimate their costs and explore differences in financial impact. This was necessary to facilitate further investigation as to what extent the intensity of preop and postop bariatric surgical care is a factor which may affect patient outcomes after surgery.
Results
A comparison of Scotland’s tier-four pathways by bariatric site
All 10 NHS-funded SCOTS study sites provided information on their bariatric surgery services. The questionnaires were completed, generally by the bariatric dietician or nurse, and returned by e-mail or hard copy to the investigator. Most patients were referred via GPs, diabetes clinics or consultants. Age range of patients was 18–60 years. Each site’s bariatric surgery preop and postop care pathways and eligibility criteria regarding glycaemic control and target weight loss pre-surgery were compared (see ). It was assumed that BMI and comorbidity eligibility criteria would comply with NICE guidance. Note that one site (site 10) specified sleep apnoea treatment; this was not costed in calculations as a cost of surgery as it is considered a cost related to an obesity comorbidity, which would have been treated regardless of the bariatric surgery.
A comparison of Scotland’s tier-four pathways by NHS-funded SCOTS study site
Classification of Scotland’s tier-four pathway costs
Results of a sensitivity analysis (SA) show nearly a five fold difference in costs per patient for preop services (range £226–£1071) and more than a three fold difference for postop services (range £259–£896, see ). The provision of services was variable regarding the format of delivery of sessions (group as one-to-one sessions), and frequency and length of access to psychology and dietetics before and after surgery. Access to psychological support was variable both preoperatively and postoperatively, with sessions lasting from 30 minutes to 2 hours, if this was actually provided. Similarly, for dieticians, some sites offered a one-off appointment pre-surgery, while others provided a regular group service over a number of weeks. Postop follow-up was more consistent, with regular reviews by dieticians, though this was far from standardised across sites. The full cost breakdown is provided in Report Supplementary Material 6.
Costs of tier-four pathways classified as low, medium and high intensity
Discussion
Bariatric surgery care pathways are widely regarded as varying considerably and international bariatric guidance is not specific with regard to the optimal model of care.70 The results described in this chapter illustrate the large nationwide variability in preop and postop care, a likely consequence of widespread uncertainty regarding best practice and a lack of more detailed guidance with respect to service delivery. There is little evidence as to whether intensive preop and postop care improves outcomes and is cost-effective compared to less intensive care. This is likely to be more complicated than one standard pathway for all, with patient preferences also paramount in terms of type of provision (one-to-one or group sessions, for example). Furthermore, pre-surgery targets vary widely95 but are often low-cost group interventions and funded from a separate budget to surgery. Maximum cost is around £100–£200 per patient. However, these targets do add to the complexity of the pathway for the patients and variation in time and access to surgery, and therefore the usefulness of these targets is currently a subject of debate.96–99
Impacts resulting from the benefits of dietician and psychological support prior to bariatric surgery have been published. Livhits et al.100 undertook a systematic review which found that preop weight loss appears to be associated with greater weight loss postoperatively. In a more recent review, Gerber et al.101 found the same beneficial effects from preop weight loss. On the other hand, it has been shown that psychological support before and after bariatric surgery had no impact on weight loss.102 This study recommends further research to evaluate the longer-term implications for both weight loss and psychological support, and thereby the most effective timing for delivery of these interventions. As to why some sites offer more comprehensive services than others, decisions on staff resourcing are possibly being made on the basis of cost and availability of specialists, as there is currently no evidence as to whether these different models of care pathways improve outcomes. Indeed, this study illustrates how variable these costs are, even across health centres within the same country context, and this difference alone is worth highlighting. Therefore, it is important to evidence outcomes of these services.
Furthermore, there is a concern that bariatric surgery cost-effectiveness models may either omit pre-surgery and post-surgery care costs as part of their economic analyses or treat patients and the delivery of these services homogeneously by applying average costs. In a systematic review of a critical appraisal of economic evaluations of bariatric surgery,103 the considerable heterogeneity of what costs are included in economic studies and the frequent omission of different types of healthcare resource use were highlighted. Despite the identification of preoperative and postoperative costs, there was no detail reported on care pathways explicitly as an important cost component of an economic evaluation of bariatric surgery. A recent study by Gulliford et al.,104 estimating the costs of bariatric surgery drawn from UK
NHS tariffs, included preoperative weight management as part of the cost of the surgical procedure but only referred to the cost of medical weight-management services. There was no reference to bariatric surgery care pathway costs being included.104 In the same model, a flat rate of £875 was also included for postoperative reviews. Procedure costs are not captured here and are assumed to be relatively standardised given the clear guidance on surgical procedures and, in Scotland, there is national procurement so device costs would also be standard across all sites. In their systematic review, Picot et al.105 found the costs of bariatric surgery generally to be presented as standard unit costs with aggregate costs differing dependent on what is included in the total costs of surgery rather than any differences due to site variation. One study106 did find variation by gender but offered no explanation as to why.
The aim of this research was to understand whether differences in these care pathways are predictors of health outcomes, and thus influence cost-effectiveness from the benefit side. This study underlines the need to better understand the cost-effectiveness of bariatric surgery care pathways, and whether the varying level of intensity of services offered is an important factor in influencing outcomes. The SCOTS study provides the follow-up data required to assess whether this classification of preop and postop care pathways is a predictor of health outcomes. Classification of the intensity of preop and postop bariatric surgical care can now be considered for investigation as a factor which may affect patient outcomes after surgery. If further findings do demonstrate that more intensive (and expensive) services lead to better outcomes, it is not envisaged that this will change bariatric surgery from being cost-effective at the usual willingness-to-pay thresholds for reimbursement on the NHS given the modelled ICER of £10,126 per quality-adjusted life year.55 However, budgetary impact is an important consideration and it is acknowledged that these costs do matter for payers, hospital resource use and more local-level decision-making. Should these pathways be found to be predictors of better health outcomes, the case for investment in these care pathways would be self-evident.
Conclusions
This study, focusing on preop costs and the first 12 months following surgery in which the majority of costs will occur, has illustrated the large nationwide variability in preop and postop care pathways across Scotland, and the subsequent financial impact on the provision of bariatric surgery services. This is a likely consequence of widespread uncertainty regarding best practice and a lack of more detailed guidance regarding service delivery. Health economic analyses do not always capture these costs103 or apply a flat rate.104 There is a lack of evidence base and a clear requirement for the evaluation of bariatric surgical services to identify the care pathways preceding and following surgery which lead to the largest improvements in health outcomes and remain cost-effective to the health provider.
