Health Economics @NIHR GSU

Health Economics is the study of how individuals, healthcare providers and governments make health and healthcare decisions in the presence of limited resources. Thus, it applies the general principles of economics to the allocation of scarce resources in health and healthcare. In limited resource settings, appropriate information on the relative clinical effectiveness and cost-effectiveness of health care interventions are vital to support decisions on resource allocation.

In collaboration with the NIHR Global Surgery Unit (GSU) Policy & Implementation Committee, health economic information will be used to guide and support decision making in low- and middle- income (LMIC) settings. To this end, the planned health economic evidence generation includes the undertaking of a range of different approaches such as systematic reviews, economic modelling, cost studies and economic evaluations alongside trials.

Health Economics Activities with Clinical Trials at Global Surgery Unit

Surgical patients are at high risk of exposure to respiratory infections transmissions including coronavirus disease 2019 (COVID-19) and other complications. Despite this, some surgeries especially non-elective ones have to be performed even during the pandemic period which will likely increase post-operative pneumonia cases, hospital resource use and mortality rates.

The PROTECT Surg Trial has been planned to estimate the impact of interventions hypothesised to avert postoperative pulmonary complications during the COVID-19 pandemic. It is an international multicentre adaptive trial which will establish as quick as possible beneficial interventions, drop interventions with no evidence of effectiveness and introduce new interventions with potential of reducing pulmonary complications during the COVID-19 pandemic. In the initial design, the trial will assess the effectiveness of three interventions compared to normal practice (no trial drug): (1) lopinavir-Ritonavir (2) hydroxychloroquine and (3) a combination of Lopinavir-Ritonavir and hydroxychloroquine.

The health economics team will collaborate with the clinical team on the PROTECT Surg Trial to evaluate whether the initial three treatment drugs or other drugs that might be introduced in the trial will reflect value for money in the trial settings. The cost-effectiveness analysis which will be conducted for each participating country will be important in determining whether the benefits of the intervention drugs are reflects value for money in the trial countries.  The analysis will be conducted after completion of follow-up of the first 250 patients per arm and thereafter for every 200 patients. Because of little evidence on the cost and benefits of the interventions there is a possibility of another intervention having higher once more patients are assessed. Therefore cost-effectiveness decision will have uncertainties which can be reduced by conducting further research. So during every analysis we will calculate the expected cost of uncertainty and the next 200 patients should be recruited if expected cost of uncertainty is higher than the cost of the next recruitment.

The FALCON trial looks into the prevention of surgical site infections (SSI) in low- and middle- income countries.

The health economics sub-study within FALCON is named KIWI (Key Resource Use In Wound Infection).

Surgical site infection (SSI) is a worldwide problem which has morbidity, mortality and financial consequences [1-3].Previous studies in LMICs on the costs of SSI have been limited by small sample size single-centre hospitals which did not capture costs occurring after hospital discharge. The lack of follow up is a problem as SSI can occur after discharge [4] and costs associated with SSI have been shown to persist beyond 30 days [5]. The main FALCON trial is assessing different treatment combinations to reduce Surgical Site Infection (SSI). The FALCON KIWI sub study is assessing the resource use and costs for patients with and without SSI across several hub countries.

KIWI includes resource use collection (via additional CRFs) up to the 30 day follow-up assessment for patients and extended follow-up for any patients with an ongoing wound infection up to 60 days post-surgery.

References

1. Allegranzi B, Bagheri Nejad S, Combescure C, Graafmans W, Attar H, Donaldson L, et al. Burden of endemic health-care-associated infection in developing countries: systematic review and meta-analysis. Lancet (London, England). 2011;377(9761):228-41. Epub 2010/12/15. doi: 10.1016/s0140-6736(10)61458-4. PubMed PMID: 21146207.
2. Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for Prevention of Surgical Site Infection, 1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. American journal of infection control. 1999;27(2):97-132; quiz 3-4; discussion 96. Epub 1999/04/10. PubMed PMID: 10196487.
3. Gheorghe A, Moran G, Duffy H, Roberts T, Pinkney T, Calvert M. Health Utility Values Associated with Surgical Site Infection: A Systematic Review. Value in health : the journal of the International Society for Pharmacoeconomics and Outcomes Research. 2015;18(8):1126-37. Epub 2015/12/22. doi: 10.1016/j.jval.2015.08.004. PubMed PMID: 26686800.
4. Lankiewicz JD, Yokoe DS, Olsen MA, Onufrak F, Fraser VJ, Stevenson K, et al. Beyond 30 days: does limiting the duration of surgical site infection follow-up limit detection? Infect Control Hosp Epidemiol. 2012;33(2):202-4. Epub 2012/01/10. doi: 10.1086/663715. PubMed PMID: 22227993; PubMed Central PMCID: PMCPMC3608264.
5. Petrosyan Y, Thavorn K, Maclure M, Smith G, McIsaac DI, Schramm D, et al. Long-term Health Outcomes and Health System Costs Associated With Surgical Site Infections: A Retrospective Cohort Study. Ann Surg. 2019. Epub 2019/03/26. doi: 10.1097/sla.0000000000003285. PubMed PMID: 30907758.

The PENGUIN trial is a 2 x 2 factorial, international pragmatic randomised trial. The trial aims to assess whether preoperative chlorhexidine mouthwash when compared to no-mouthwash-surgery can reduce incidence of post-operative pneumonia (POP) and whether perioperative liberal oxygen versus restrictive oxygen can reduce incidence surgical site infections (SSI) at 30-days among abdominal surgery patients.

Two preliminary economic evaluations will be conducted prior to the clinical trial:

(1) The PENGUIN mouthwash preliminary economic evaluation. POP is associated with high healthcare costs, post-operative adverse events and mortality. The post-operative mortality rates associated with POP are more frequent in low and middle-income countries (LMICs) compared to high income countries (HICs). There is some evidence from studies conducted among cardiac surgery subjects in HICs suggesting that preoperative chlorhexidine mouthwash can reduce the incidence of POP however there is no evidence of it being effective in other income settings and other surgeries. Furthermore, due to the emerging of the corona virus 2019 disease (COVID-19) it is expected that POP rates will be higher during the COVID-19 pandemic period compared to the pre-COVID-19 period.

The preliminary economic evaluation will assess the potential cost-effectiveness of preoperative chlorhexidine mouthwash surgery in reducing POP among abdominal surgery patients when compared to no-mouthwash surgery. A decision model taking the South African health care perspective will be built for the analysis. Model input parameters: costs, probabilities and outcomes will be estimated from literature. The analysis will compare the cost-effectiveness of the intervention in the absence and presence of COVID-19 to identify the impact of COVID-19 on mouthwash cost-effectiveness.

Alongside the trial, the health economics team will also conduct a trial-based economic evaluation to assess the cost-effectiveness of the mouthwash in reducing POP using primary data.

Systematic review: costs of pneumonia following abdominal surgery

The objective of the systematic review is to estimate the costs of post-operative pneumonia among abdominal surgery patients. This information will be important in prioritising healthcare resources by informing healthcare providers and policy makers about the costs that can be saved by reducing post-operative pneumonia incidence. Feeding into the PENGUIN mouthwash preliminary cost-effectiveness analysis, the cost estimates from the review will be used as input parameters in the preliminary model.

(2) The PENGUIN oxygen preliminary economic evaluation. Surgical site infections (SSI) are one of the most common medical care advents events. The world Health Organisation (WHO) recommended perioperative high dose fraction of inspired oxygen as an intervention for reducing SSIs. However, there is mixed evidence on the effectiveness and safety of the intervention compared to using perioperative low dose oxygen concentration. One of the objectives of the PENGUIN trial is to provide evidence whether perioperative high dose oxygen concentration is effective and safe in reducing the incidence of SSIs.

The Global Surgery Collaborative health economics