The carbon footprint of pathology testing

Blood-sparing techniques prevalence in adult intensive care units: A multicentre survey study

INTRODUCTION

Anaemia is a common condition in patients admitted to intensive care units (ICUs). It is also well known that a significant amount of the carbon dioxide produced by health services is likely attributable to blood donation, testing, and the manufacture, storage, and distribution of blood components. To mitigate this, prevention strategies such as blood-sparing techniques are available. There is a lack of knowledge regarding the use of such techniques in ICUs in Spain and Latin America, healthcare systems with very different health expenditures per capita. The aim is to assess the degree of implementation of blood-sparing techniques in these regions.

METHODS

Cross-sectional online multicentre survey. 251 ICUs in Spain and 53 in Latin America (20 in Argentina, 20 in Colombia, 13 in Ecuador) participated. A 20-item survey on the use of point-of-care, small-volume tubes (SVT), and closed-blood sampling devices (CBSD) was validated. Effect sizes were calculated using Phi (φ) or Cramer's V (V).

RESULTS

A response rate of 77% was obtained for Spain and 96% for Latin America. In Spain, the majority of ICUs were affiliated with public hospitals (88.1%, 171/194) while in Latin America, most were associated with private hospitals (56.9%, 29/51). Regarding the use of point-of-care testing, 67.5% of Spanish ICUs, compared to 35.3% of Latin Americans, reported frequent use (V=0.343). In 91.7% of Spanish ICUs and 58.9% of Latin Americans, SVTs were rarely or never used (V=0.380). The use of CBSD was significantly lower in Spain for both arterial and central venous catheters (V=0.336). Private hospitals used more CBSD in arterial catheter than public ones (27% vs 8.3%, V=0.278).

CONCLUSION

Point-of-care testing can be improved in Latin America, while the use of CBSD and small-volume tubes can be enhanced in Spain. Private hospitals tend to implement blood-sparing techniques more effectively than public hospitals.

Environmental impact of a blood test reduction intervention in adult intensive care units: A before and after quality improvement project

BACKGROUND

Pathology testing is a very common investigation in the intensive care unit (ICU). Many tests are ordered on a routine basis rather than for a specific clinical indication, resulting in potential patient harm and unnecessary financial and environmental costs.

OBJECTIVE

The objective of this study was to determine whether a multifaceted intervention based on the principles of education, audit, and feedback can result in a decrease in unnecessary pathology tests without a commensurate increase in adverse patient outcomes and to measure this decrease in terms of the associated reduction in environmental and financial costs.

METHODS

A before and after quality improvement project was conducted between 2017 and 2019 across four ICUs in three 12-month phases, divided according to baseline, intervention implementation, and follow-up. Local clinician champions from each site partnered with the project coordinating centre to develop and implement a range of interventions based on the principles of education, audit, and feedback. Data were collected for the number of pathology tests performed and the clinical characteristics of patients admitted to a participating ICU across the three phases.

RESULTS

A total of 196 323 arterial blood gases and 460 258 other tests across eight categories were performed on the 22 210 patients admitted to participating ICUs during the project. A decrease in testing was observed across all but one category, with the greatest reduction seen in arterial blood gases (31.2% reduction in tests per bed-day). Across all categories, this equated to a mean reduction of 1.8 tCO2e (tonnes of carbon dioxide equivalent), a potential estimated total saving of Australian dollar $918 497.50. No increase in adverse clinical outcomes was observed.

CONCLUSION

A multifaceted intervention based on the principles of education, audit, and feedback can produce a significant decrease in the number of unnecessary pathology tests performed. This reduction translates to substantial environmental and financial savings without any associated increase in adverse patient outcomes.

The carbon footprint of external beam radiotherapy and its impact in health technology assessment

Background

The major drivers of carbon dioxide (CO2eq) emissions of external beam radiation therapy (EBRT) are not well known and limit our ability to initiate mitigation strategies.

Material and methods

We describe the carbon footprint of four typical centers. We explore direct EBRT associated factors such as the impact of fractionation and use of MRI-LINAC, as well as indirect factors (e.g. patient rides). Treatment strategy related CO2eq emissions are included in a health technology assessment analysis that takes into account CO2eq emissions.

Results

A typical EBRT treatment emits from 185 kgCO2eq to 2066 kgCO2eq. CO2eq emissions are mostly driven by (i) accelerator acquisition and maintenance (37.8 %), (ii) patients and workers rides (32.7 %), (iii) drugs and medical devices (7.3 %), (iv) direct energy consumption (6.1 %), and (v) building and bunker construction (5.6 %) with a substantial heterogeneity among centers. Hypofractionation has a strong impact to mitigate emissions. MRI-LINAC is associated with a substantial increase in CO2eq emissions per fraction and requires ultra hypofractionation in 5 fractions to achieve a similar carbon footprint compared to 20 fractions treatment schemes. The expected limited small increase in toxicities due to hypofractionation (when existing) are in the same range as avoided detrimental effects to future people's health thanks to CO2eq mitigation.

Conclusion

Carbon footprint of EBRT is not neglectable and could be mitigated. When safely feasible, hypofractionation is one of the main factors to decrease this impact. Taking into account CO2eq emissions has a substantial impact on the health technology assessment of EBRT, favoring hypofractionated regimens.

Beyond the incubator: applying a "one health" approach in the NICU

A "one health" approach recognises that human health, animal health and planetary health are closely interlinked and that a transdisciplinary approach is required to fully understand and maintain global health. While, by necessity, Neonatal Intensive Care has traditionally focused on the acutely unwell newborn, the avoidance of long-term harm is core to many management decisions. The COVID 19 pandemic and climate crisis have brought into sharp relief the importance of a "one health" approach as part of long-term health promotion in the holistic care of neonates, who may survive to experience the burden of future environmental crises. This narrative review seeks to integrate what we know about "one health" issues in the neonatal intensive care unit, notably antimicrobial resistance and climate change, and suggest "everyday changes" which can be utilised by practitioners to minimise the impact of neonatal intensive care on these global health issues. Many of the changes suggested not only represent important improvements for planetary health but are also core to good neonatal practice. IMPACT: Neonatal patients are likely to bear the burden of future environmental crises including pandemics and climate related disasters. While the focus of intensive care practitioners is acute illness, awareness of "one health" problems are important for our smallest patients as part of preventing long-term harm. High quality neonatal care can benefit both the planet and our patients.

Approaching sustainability in Laboratory Medicine

INTRODUCTION

Clinical laboratories and the total testing process are major consumers of energy, water, and hazardous chemicals, and produce significant amounts of biomedical waste. Since the processes in the clinical laboratory and the total testing process go hand in hand it mandates a holistic, and comprehensive approach towards sustainability.

CONTENT

This review article identifies the various sources and activities in Laboratory Medicine that challenge sustainability and also discusses the various approaches that can be implemented to achieve sustainability in laboratory operations to reduce the negative impact on the environment.

SUMMARY

The article highlights how the integration of technological advancements, efficient resource management, staff training and sensitization, protocol development towards sustainability, and other environmental considerations contributes significantly to a sustainable healthcare ecosystem.

OUTLOOK

Variables and resources that negatively impact the environment must be identified and addressed comprehensively to attain a long-lasting level of carbon neutrality.

Healthcare-related carbon footprinting-lower impact of a coronary stenting compared to a coronary surgery pathway

Healthcare is a major generator of greenhouse gases, so consideration of this contribution to climate change needs to be quantified in ways that can inform models of care. Given the availability of activity-based financial data, environmentally-extended input-output (EEIO) analysis can be employed to calculate systemic carbon footprints for healthcare activities, allowing comparison of different patient care pathways. We thus quantified and compared the carbon footprint of two common care pathways for patients with stable coronary artery disease, with similar clinical outcomes: coronary stenting and coronary artery bypass surgery (CABG). Healthcare cost data for these two pathways were disaggregated and the carbon footprint associated with this expenditure was calculated by connecting the flow of money within the economy to the greenhouse gases emitted to support the full range of associated activities. The systemic carbon footprint associated with an average stable patient CABG pathway, at a large tertiary referral hospital in Sydney, Australia in 2021-22, was 11.5 tonnes CO2-e, 4.9 times greater than the 2.4 tonnes CO2-e footprint of an average comparable stenting pathway. These data suggest that a stenting pathway for stable coronary disease should be preferred on environmental grounds and introduces EEIO analysis as a practical tool to assist in health-care related carbon footprinting.

Direct-to-consumer testing as consumer initiated testing: compromises to the testing process and opportunities for quality improvement

Direct-to-consumer testing (DTCT) refers to commercial laboratory tests initiated by laypersons without the involvement of healthcare professionals. As this market grows in size and variety of products, a clear definition of DTCT to ground the conceptualization of their harms and benefits is needed. We describe how three different modalities of DTCT (home self-testing, self-sampled tests, and direct access tests) present caveats to the traditional testing process ('brain-to-brain loop'), and how this might differ between medical vs. non-medical laboratories. We make recommendations for ways to improve quality and reduce errors with respect to DTCT. The potential benefits and harms of DTCT will invariably depend on the context and situation of individual consumers and the types of tests involved. Importantly, implications for both consumers and the healthcare system should be considered, such as the effects on improving health outcomes and reducing unnecessary testing and use of clinical resources. 'Consumer initiation' must be a central defining characteristic of DTCT, to clearly demarcate the key drawbacks as well as opportunities of this type of testing from a laboratory specialists' perspective. The concept of 'consumer initiated testing' should also help define DTCT regulation, and provide a locus of efforts to support consumers as the main decision-makers in the purchasing and conducting of these tests in the absence of clinician gatekeeping.

Climate change and children's respiratory health

Climate change has significant consequences for children's respiratory health. Rising temperatures and extreme weather events increase children's exposure to allergens, mould, and air pollutants. Children are particularly vulnerable to these airborne particles due to their higher ventilation per unit of body weight, more frequent mouth breathing, and outdoor activities. Children with asthma and cystic fibrosis are at particularly high risk, with increased risks of exacerbation, but the effects of climate change could also be observed in the general population, with a risk of impaired lung development and growth. Mitigation measures, including reducing greenhouse gas emissions by healthcare professionals and healthcare systems, and adaptation measures, such as limiting outdoor activities during pollution peaks, are essential to preserve children's respiratory health. The mobilisation of society as a whole, including paediatricians, is crucial to limit the impact of climate change on children's respiratory health.

The carbon footprint of health care delivery in Western Australia's public health system

Background

Health systems have a dual imperative to take action on climate change. First, they must develop climate resilient health services in response to the direct and indirect impacts of climate change on health. Second, they must reduce their own carbon footprint since health systems are a significant contributor to global greenhouse gas emissions.

Methods

An environmentally-extended multi-region input-output analysis was carried out, incorporating National Accounts data for Australia and annual expenditure data from WA Health for financial year 2019-20. Expenditure data were categorised to one of 344 economic sectors and by location of the provider of goods or services purchased.

Findings

WA Health contributes 8% of WA's total carbon footprint, driven by expenditure on chemicals (23.8% of total), transport (20.2% of total), and electricity supply (19.7% of total). These 3 sectors represent 63.7% of WA Health's carbon footprint, but only 10.8% of its total expenditure.

Interpretation

Reducing emissions related to health service provision in WA will require a holistic approach that leverages carbon footprinting insights and integrates them into organisational decision-making across all health programs. The high carbon-intensity of the transport and chemicals sectors supports previous research calling for a reduction in unnecessary pathology testing and the transition to delivery of non-urgent health care via sustainable models of telehealth. The impact of WA's size and location presents challenges, with a predominantly non-renewable energy supply and reliance on transport and supply chains from other states adding significantly to emissions.

Funding

The study received funding from the Australian Research Council, The University of Sydney, and the WA Department of Health. The full list of funding information can be found in Acknowledgements.

Effective stewardship strategies to enhance appropriateness of refer-out test requests in a Canadian tertiary centre laboratory

OBJECTIVES

Specialized testing conducted in reference laboratories is costly and often not optimally directed. Since 2016, our institution has worked to ensure the appropriateness of refer-out (RO) tests. We examine the impact of utilization initiatives on the patterns of requests and completed tests.

DESIGN AND METHODS

In 2016, 81 RO tests were selected for a more rigorous approval process. Physicians not pre-approved for testing received a prompt to consult with laboratory subject matter experts (SMEs) for further detail. After review, SMEs provided responses, approving or rejecting requests based on clinical relevance. Stewardship activities also included: repatriating tests locally, preferring Canadian over foreign institutions, unbundling tests, distributing educational memos, and introducing staged testing. We collected data on the number of requested (NoR) and number of completed (NoC) tests in 2015, before the implementation of the new vetting procedures, and for the post-implementation phase from 2016-2022.

RESULTS

For 62 targeted RO tests (including trace metals, vitamins, antibodies, and endocrine-related tests), there was a 33% reduction in NoR and a 51% reduction in NoC in 2022 compared to 2015. The total savings for the study period based on NoC was $807,736. The NoC rate for Neuronal antibody tests decreased to 48.6% in 2022, with cost savings of $17,123, and an additional $50,000 saved by changing the testing site. Insourcing apolipoprotein B and fecal calprotectin tests resulted in cost savings of $3,380 and $3,371, respectively, in 2022.

CONCLUSIONS

Automated messaging followed by a formal review of RO test requests is an effective utilization strategy that prevents redundant or clinically unjustified testing. This approach leads to significant economic savings and is expected to improve the efficiency of patient care.

Blood over-testing: impact, ethical issues and mitigating actions

Plenty of studies demonstrate that hospital-acquired anemia (HAA) can increase transfusion rates, mortality, morbidity and cause unnecessary patient burden, including additional length of hospital stay, sleep disruption and venipuncture harms resulting from blood samples unlikely to change clinical management. Beyond patient costs, community costs should also be considered, such as laboratory time and resources waste, environmental impact, increasing pressure on labs and fewer tests available on time for patients who can benefit from them most. Blood over-testing does not support the principles of non-maleficence, justice and respect for patient autonomy, at the expense dubious beneficence. Reducing the number and frequency of orders is possible, to a certain extent, by adopting nudge strategies and raising awareness among prescribing doctors. However, reducing the orders may appear unsafe to doctors and patients. Therefore, reducing blood volume from each order is a better alternative, which is worth implementing through technological, purchasing and organizational arrangements, possibly combined according to need (smaller tubes, adequate analytic platforms, blind dilution, blood conservative devices, aggregating tests and laboratory units).

Mapping the Environmental Co-Benefits of Reducing Low-Value Care: A Scoping Review and Bibliometric Analysis

Reducing low-value care (LVC) and improving healthcare's climate readiness are critical factors for improving the sustainability of health systems. Care practices that have been deemed low or no-value generate carbon emissions, waste and pollution without improving patient or population health. There is nascent, but growing, research and evaluation to inform practice change focused on the environmental co-benefits of reducing LVC. The objective of this study was to develop foundational knowledge of this field through a scoping review and bibliometric analysis. We searched four databases, Medline, Embase, Scopus and CINAHL, and followed established scoping review and bibliometric analysis methodology to collect and analyze the data. A total of 145 publications met the inclusion criteria and were published between 2013 and July 2023, with over 80% published since 2020. Empirical studies comprised 21%, while commentary or opinions comprised 51% of publications. The majority focused on healthcare generally (27%), laboratory testing (14%), and medications (14%). Empirical publications covered a broad range of environmental issues with general and practice-specific 'Greenhouse gas (GHG) emissions', 'waste management' and 'resource use' as most common topics. Reducing practice-specific 'GHG emissions' was the most commonly reported environmental outcome. The bibliometric analysis revealed nine international collaboration networks producing work on eight key healthcare areas. The nineteen 'top' authors were primarily from the US, Australia and Canada.

Evaluating the carbon footprint of sedation practices in intensive care

BACKGROUND

Healthcare's carbon footprint contributes to 4.4% of global net emissions and intensive care units (ICUs) are very resource intensive. Existing studies on environmental sustainability in ICUs focused on carbon footprint generated from energy and electricity consumption, use of medical consumables and equipment, but few studies quantified carbon footprint generated from pharmaceuticals used in ICUs.

AIM

To evaluate carbon footprint arising from sedation practices in the ICUs.

STUDY DESIGN

A pilot, prospective observational study was conducted in two ICUs from 1 August to 22 September 2022 in Singapore General Hospital. Adult patients who were consecutively sedated, intubated and expected to be mechanically ventilated for at least 24 h were included. Total amount of analgesia and sedatives used and wasted in eligible patients were collected. Carbon emission from ICU sedation practices were then quantified using available life cycle assessment data.

RESULTS

A total of 31 patients were recruited. Top analgesia and sedative used in both ICUs were fentanyl and propofol, respectively. Carbon footprint from sedative usage and wastage across 7 weeks in both ICUs were 2.206 kg CO2-e and 0.286 g CO2-e, respectively. In total, this equates to driving 15.8 km by car. Proportion of drug wasted ranged from 5.1% to 25.0%, with the top reason for wastage being the drug was no longer clinically indicated. Recommendations to reduce carbon footprint include choosing sedatives with lower carbon emissions where possible and having effective communication among doctors and nurses regarding management plans to minimize unnecessary wastage.

CONCLUSION

Our study quantified carbon footprint arising from sedation practices, mainly drug usage and wastage in two ICUs in Singpore General Hospital.

RELEVANCE TO CLINICAL PRACTICE

Adopting a holistic approach to environmental sustainability in the ICU, sedation practices also contribute to generating greenhouse gases, albeit small, and can be targeted to reduce unnecessary carbon footprint.

Methods to Include Environmental Impacts in Health Economic Evaluations and Health Technology Assessments: A Scoping Review

OBJECTIVES

The environmental impacts of healthcare are important factors that should be considered during health technology assessments. This study aims to summarize the evidence that exists about methods to include environmental impacts in health economic evaluations and health technology assessments.

METHODS

We identified records for screening using an existing scoping review and a systematic search of academic databases and gray literature up to September 2023. We screened the identified records for eligibility and extracted data using a narrative synthesis approach. The review was conducted following the JBI Manual for Evidence Synthesis and reported according to the Preferred Reporting Items for Systematic Reviews and Meta Analyses Extension for Scoping Reviews checklist.

RESULTS

We identified 2898 records and assessed the full text of 114, of which 54 were included in this review. Ten methods were identified to include environmental impacts in health economic evaluations and health technology assessments. Methods included converting environmental impacts to dollars or disability-adjusted life years and including them in a cost-effectiveness, cost-utility, or cost-benefit analysis, calculating an incremental carbon footprint effectiveness ratio or incremental carbon footprint cost ratio, incorporating impacts as one criteria of a multi-criteria decision analysis, and freely considering impacts during health technology assessment deliberation processes.

CONCLUSIONS

Methods to include environmental impacts in health economic evaluations and health technology assessments exist but have not been tested for widespread use by health technology assessment agencies. Further research and implementation work is needed to determine which method can best aid decision makers to choose low environmental impact healthcare interventions.

Cutting back on low-value health care practices supports sustainable kidney care

July 2023 marked the hottest month on record, underscoring the urgent need for action on climate change. The imperative to reduce carbon emissions extends to all sectors, including health care, with it being responsible for 5.5% of global emissions. In decarbonizing health care, although much attention has focused on greening health care infrastructure and procurement, less attention has focused on reducing emissions through demand-side management. An important key element of this is reducing low-value care, given that ≈20% of global health care expenditure is considered low value. "Value" in health care, however, is subjective and dependent on how health outcomes are regarded. This review, therefore, examines the 3 main value perspectives specific to health care. Clinical effectiveness defines low-value care as interventions that offer little to no benefit or have a risk of harm exceeding benefits. Cost-effectiveness compares health outcomes versus costs compared with an alternative treatment. In this case, low-value care is care greater than a societal willingness to pay for an additional unit of health (quality-adjusted life year). Last, community perspectives emphasize the value of shared decision-making and patient-centered care. These values sit within broader societal values of ethics and equity. Any reduction in low-value care should, therefore, also consider patient autonomy, societal value perspectives and opportunity costs, and equity. Deimplementing entrenched low-value care practices without unnecessarily compromising ethics and equity will require tailored strategies, education, and transparency.

Reducing reflex first-line prescriptions in a surgical pathology laboratory: toward sustainable practice with positive economic and clinical effects

In surgical pathology departments, reflex first-line techniques (RFLTs) are aimed at reducing workloads and addressing recent shortages of medical personnel. However, the impacts thereof on economic and diagnostic factors have been poorly addressed. Also, in the era of global warming, environmental considerations are crucial. This study assessed the economic and diagnostic efficacies of routine pathological RFLT and the quality of care and sustainability. Ten RFLTs of the Bordeaux University Hospital pathology department (six special stains, one cytology technique, and three immunohistochemical tests) were studied. First, a retrospective economic analysis evaluated the average cost of these RFLTs per slide and per year. Second, diagnostic relevance was prospectively surveyed. Third, the effects of changes made were analyzed over 2 years. The ten RFLTs were associated with average annual costs of €46,708. Diagnostic relevance analysis indicated that most stains were unnecessary; only 17% were requested as second-line techniques. Elimination of 7/10 tests afforded annual cost savings of €22,522 and reduced the workload by 5568 tests/year, without compromising the workflow or diagnostic quality. Seven of ten RFLTs could be eliminated without compromising diagnostic quality or the workflow. This afforded not only financial benefits but also positive social and environmental impacts. We offer valuable insights into appropriate practices in surgical pathology laboratories. Collaboration between the medical and technical teams was crucial; other healthcare sectors would also benefit from our approach.

The carbon footprint of critical care: a systematic review

PURPOSE

The provision of healthcare is a substantial global contributor to greenhouse gas (GHG) emissions. Several medical specialties and national health systems have begun evaluating their carbon emission contributions. The aim of this review is to summarise and describe the carbon footprint resulting from the provision of adult, paediatric and neonatal critical care.

METHODS

A systematic search of Embase, Cochrane and Web of Science was performed in January 2023. Studies reporting any assessment of the carbon footprint of critical care were included. No language restrictions were applied. GHG emissions from life cycle assessments (LCA) were reported, in addition to waste, electricity and water use. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guideline was followed.

RESULTS

In total, 13 studies assessing and describing the environmental impact of 36 adult or paediatric intensive care units (ICUs) were included. Two studies described full LCAs, seven reported waste only, two provided audits of unused medical supplies, one reported electricity use, and one study described a Material Flow Analysis. The estimated carbon emissions from critical care range between 88 kg CO2e/patient/day and 178 kg CO2e/patient/day. The two predominant sources of carbon emissions in critical care originate from electricity and gas use, as well as consumables. Waste production ranged from 1.1 to 13.7 kg/patient/day in the 6 studies where mean waste could be calculated.

CONCLUSION

There is a significant carbon footprint that results from intensive care provision. Consumables and waste constitute important, measurable, and modifiable components of anthropogenic emissions. There remains uncertainty due to a lack of literature, several unstudied areas of carbon emissions from critical care units, and within measured areas, measurement and reporting of carbon emissions are inconsistent.

Best practices for iatrogenic anaemia prevention in the intensive care unit: Blood-sparing techniques

Anaemia is a common issue in patients who are admitted to intensive care units and worsens their condition throughout the stay due to the extraction of blood for diagnostic purposes. It is also well-known that an important amount of the carbon dioxide produced by health services is likely attributable to blood donation, testing and manufacture, storage or distribution of blood components. This must be taken into account to perform nursing interventions consistent with the idea of sustainable health care. In this regard, within patient blood management bundles, with the objective of minimizing the use of blood products, it is recommended to use blood-sparing techniques: small volume tubes (SVT) or closed-blood sampling devices (CBSD). Published studies before 2014 (excepting two more recent ones) have shown that by themselves, both techniques reduce drawn volume but do not decrease haemoglobin reduction and/or need of transfusion. Given the lack of cost-effectiveness studies, it may be easier to implement the use of CBSD as it does not require prior consensus on the discard volume or adaptations in the processing of laboratory tests, as is the case with SVT.

What is the environmental impact of a blood transfusion? A life cycle assessment of transfusion services across England

BACKGROUND

Healthcare activities significantly contribute to greenhouse gas (GHG) emissions. Blood transfusions require complex, interlinked processes to collect, manufacture, and supply. Their contribution to healthcare emissions and avenues for mitigation is unknown.

STUDY DESIGN AND METHODS

We performed a life cycle assessment (LCA) for red blood cell (RBC) transfusions across England where 1.36 million units are transfused annually. We defined the process flow with seven categories: donation, transportation, manufacturing, testing, stockholding, hospital transfusion, and disposal. We used direct measurements, manufacturer data, bioengineering databases, and surveys to assess electrical power usage, embodied carbon in disposable materials and reagents, and direct emissions through transportation, refrigerant leakage, and disposal.

RESULTS

The central estimate of carbon footprint per unit of RBC transfused was 7.56 kg CO2 equivalent (CO2eq). The largest contribution was from transportation (2.8 kg CO2eq, 36% of total). The second largest was from hospital transfusion processes (1.9 kg CO2eq, 26%), driven mostly by refrigeration. The third largest was donation (1.3 kg CO2eq, 17%) due to the plastic blood packs. Total emissions from RBC transfusion are ~10.3 million kg CO2eq/year.

DISCUSSION

This is the first study to estimate GHG emissions attributable to RBC transfusion, quantifying the contributions of each stage of the process. Primary areas for mitigation may include electric vehicles for the blood service fleet, improving the energy efficiency of refrigeration, using renewable sources of electricity, changing the plastic of blood packs, and using methods of disposal other than incineration.

Impact of customized electronic duplicate order alerts on microbiology test ordering: Financial and environmental cost savings

OBJECTIVE

To estimate cost savings after implementation of customized electronic duplicate order alerts.

DESIGN

Alerts were implemented for microbiology tests at the largest public hospital in Victoria, Australia. These alerts were designed to pop up at the point of test ordering to inform the clinician that the test had previously been ordered and to suggest appropriate reordering time frames and indications.

RESULTS

In a 6-month audit of urine culture (our most commonly ordered test) after alert implementation, 2,904 duplicate requesters proceeded with the request and 2,549 tests were cancelled, for a 47% reduction in test ordering. For fecal polymerase chain reaction (PCR), our second most common test, there was a 54% reduction in test ordering. For our most commonly ordered expensive test, hepatitis C PCR, there was a 42% reduction in test ordering: 25 tests were cancelled.Cancelled tests resulted in estimated savings of AU$52,382 (US$33,960) for urine culture, AU$34,914 (US$22,442) for fecal PCR, AU$4,506 (US$2,896) for hepatitis C PCR. For cancelled hepatitis B PCR and Epstein-Barr virus (EBV) and cytomegalovirus (CMV) serology, the cost savings was AU$8,472 (US$5445). The estimated financial cost saving in direct hospital costs for these 6 assays was AU$100,274 (US$67,925) over the 6-month period. Environmental waste cost saving by weight was estimated to be 280 kg. Greenhouse gas footprint, measured in carbon dioxide equivalent emissions for cancelled EBV and CMV serology tests, resulted in a saving of at least 17,711 g, equivalent to driving 115 km in a standard car.

CONCLUSION

Customized alerts issued at the time of test ordering can have enormous impacts on reducing cost, waste, and unnecessary testing.

The carbon footprint of epidural steroid injections: A pilot study

BACKGROUND

Epidural steroid injections are common procedures in physical medicine and rehabilitation practice. However, their environmental impact has not been characterized.

OBJECTIVE

The primary aim is to estimate and compare the carbon footprint of two standard injection kits used to perform epidural steroid injections at a single academic institution. Secondary objectives were (1) to create a step-by-step guide for estimating the carbon footprint of materials and (2) to survey physicians on practice patterns and identify areas for improvement.

DESIGN

Pilot study.

SETTING

Academic medical center.

PARTICIPANTS

N/A.

INTERVENTIONS

N/A.

OUTCOME MEASURES

Carbon emissions measured in CO2 equivalents (CO2 eq).

METHODS

Using guidance from the Greenhouse Gas Protocol, the carbon footprint of the two kits was estimated by taking the sum of carbon emissions resulting from the production of the kit materials and the carbon emissions resulting from the waste disposal of the kit materials.

RESULTS

The carbon footprint of the transforaminal epidural steroid injection (TFESI) kit was estimated at 1.328 kg CO2 eq. The carbon footprint of the interlaminar epidural steroid injection (ILESI) kit was estimated at 2.534 kg CO2 eq. For both kits, the carbon emissions resulting from the production of the kits were greater than the emissions resulting from disposal. The survey of interventionalists performing TFESI revealed all respondents required materials in addition to those provided in the standard epidural kit. Despite this, kit materials were typically wasted in 62% of respondents.

CONCLUSION

Creating a methodology for quantifying carbon emissions is the first step to reducing carbon emissions. Once emissions are measured, the health care industry can determine the most effective strategies for reducing its impact. Our analysis has shown that it is feasible to perform emissions calculations and delineates a clear method with publicly available resources. Solutions to reduce epidural injection carbon footprint waste may include improved kit customization.

Disposable and reusable instruments in dental health practice: A comparison of cost factors in a public provider organization in Queensland, Australia

OBJECTIVES

Choosing between reusable instruments (RIs) and disposable instruments (DIs) for dental care provision requires a careful consideration of costs and their contributing factors, alongside other choice criteria. This study aimed to assess the current use of instruments in the West Moreton Oral Health Service (WMOHS) in Queensland, Australia, with a broader goal of informing future practice in this and comparable organizations.

METHODS

A cost model was developed reflecting costs arising from procurement, reprocessing and disposal, depending on the RI and DI composition of instrumentation. The current practice in WMOHS was compared to modular (RI-only and DI-only) strategies by considering four standard instrument sets (examination, simple extraction, surgical extraction, restoration) and the annual use of instruments in the organization at large. The use of resources (water, electricity) and emissions (waste) were quantified for each strategy. The robustness of findings was explored across a range of scenarios that involved varying instrument prices, lifespans, factors impacting on the cost of reprocessing (labour, water, energy), the cost of waste disposal and couriering.

RESULTS

At the organization level, the current mix of instruments (A$1.28 m per year) was 4% more costly than the lower cost, RI-only alternative (A$1.23 m). However, with lower DI prices or higher labour costs current practice would become the lowest cost option. Results for specific instrument sets varied by service type. DI-only offered the lowest cost option for oral examinations (A$6.29), and the current practice of mixed instrumentation for simple extractions (A$16.56). RI-only sets were less costly in more resource intensive procedures such as surgical extractions (A$40.19) and restorations (A$43.83). In terms of environmental impacts, the use of instruments based on current practice required 37% of water and energy use of an RI-only alternative and generated 36% waste of the DI-only alternative.

CONCLUSIONS

Reusable instruments are generally less costly than DIs, but for specific instrument sets the outcome depends on the type of procedure. In some circumstances, mixed instrumentation can provide the lowest cost alternative. While the WMOHS instrument mix used in current practice does not minimize cost for the provider, it may be justified in light of operational risks, logistics and uncertainty regarding cost factors.

Use of grape-based stain (Vinatela) on cervical cytology: A Peruvian validation study

Objectives

The Papanicolaou's (Pap's) stain is used for cervical cancer screening. It employs toxic-carcinogenic expensive reagents, which may not be easily accessible to many communities worldwide. The objective of this study was to validate the grape-based alcohol-extracted dye (Vinatela) on normal cervical samples for the Pap test.

Material and Methods

Samples of the two grape species were collected from two vineyards through the Agroindustrial Research Institute of Universidad Privada San Juan Bautista. The dye extraction from the grape species and the dye performance to stain cells were conducted in three phases: (a) direct staining with pre-fermentation wine products, (b) direct fragmentation of grapes and direct staining with shells of the grapes, and (c) alcoholic extraction of the dye. Vinatela obtained from two species (Vitis vinifera "Tempranillo" and "Malbec") and posterior staining of cervical samples. We conducted a double-blind validation on 30 cervical samples.

Results

The basophilic components of the cervical cells were stained. Alcoholic extraction staining protocol had a low yield. The nuclear and cytoplasmic borders, the nuclear details, and the polymorphonuclear nuclei were stained with Vinatela and could be differentiated during nuclear coloration. The initial staining protocol was 10- 20 min × (mean ~12 min) staining time. We noted a slightly better staining with V. v. Tempranillo as compared to V. v. Malbec (P = 0.045).

Conclusion

Cervical cells stained with Vinatela stain from two grape species cultivated in the Southern of Peru, showed basophilic nuclear details.

Opportunities for recycling in an automated clinical chemistry laboratory produced by the comprehensive metabolic panel

OBJECTIVES

Clinical laboratories perform a variety of tests for which biomedical waste is a byproduct. Of these, the complete metabolic panel (CMP) produces a significant portion of this waste. We investigated specific waste subsequent to performing CMPs over the course of a year and analyzed what percentage of the waste produced could have been recycled.

METHODS

Patient testing volumes were collected retrospectively from July 14, 2021, to July 14, 2022, for individual assays within the CMP performed on Abbott Alinity c instruments (n = 6). The average weights for components of the reagent kits, which includes wedges, boxes, and package inserts, were calculated. These weights, in conjunction with total patient testing volumes, were used to determine the amount of waste produced.

RESULTS

A total of 1089.2 kg of reagent kit waste was estimated to be produced by performing CMPs throughout a year. Of this waste, most (855.5 kg) was not recyclable, but a subset (233.6 kg) was. Overall, 21.4% of the total specific waste weight was found to be recyclable.

CONCLUSIONS

The CMP contributes a substantial amount of waste when performed on chemistry analyzer platforms in the clinical laboratory. Paper inserts and cardboard packaging, however, presented opportunities for recycling.

Patient, hospital and environmental costs of unnecessary bloodwork: capturing the triple bottom line of inappropriate care in general surgery patients

OBJECTIVE

To characterise the extent of unnecessary care in general surgery inpatients using a triple bottom line approach.

DESIGN

Patients with uncomplicated acute surgical conditions were retrospectively evaluated for unnecessary bloodwork according to the triple bottom line, quantifying the impacts on patients, healthcare costs and greenhouse gas emissions. The carbon footprint of common laboratory investigations was estimated using PAS2050 methodology, including emissions generated from the production, transport, processing and disposal of consumable goods and reagents.

SETTING

Single-centre tertiary care hospital.

PARTICIPANTS

Patients admitted with acute uncomplicated appendicitis, cholecystitis, choledocholithiasis, gallstone pancreatitis and adhesive small bowel obstruction were included in the study. 304 patients met inclusion criteria and 83 were randomly selected for in-depth chart review.

MAIN OUTCOME MEASURES

In each patient population, the extent of over-investigation was determined by comparing ordered laboratory investigations against previously developed consensus recommendations. The quantity of unnecessary bloodwork was measured by number of phlebotomies, tests and blood volume in addition to healthcare costs and greenhouse gas emissions.

RESULTS

76% (63/83) of evaluated patients underwent unnecessary bloodwork resulting in a mean of 1.84 phlebotomies, 4.4 blood vials, 16.5 tests and 18 mL of blood loss per patient. The hospital and environmental cost of these unnecessary activities was $C5235 and 61 kg CO₂e (974 g CO₂e per person), respectively. The carbon footprint of a common set of investigations (complete blood count, differential, creatinine, urea, sodium, potassium) was 332 g CO₂e. Adding a liver panel (liver enzymes, bilirubin, albumin, international normalised ratio/partial thromboplastin time) resulted in an additional 462 g CO₂e.

CONCLUSIONS

We found considerable overuse of laboratory investigations among general surgery patients admitted with uncomplicated acute surgical conditions resulting in unnecessary burden to patients, hospitals and the environment. This study identifies an opportunity for resource stewardship and exemplifies a comprehensive approach to quality improvement.

Status of phlebotomy tube utilization at a major medical center. Are we using too many phlebotomy tubes?

Background and objectives

Overutilization of phlebotomy tubes at healthcare facilities leads to iatrogenic anemia, patient dissatisfaction, and increase in operational costs. In this study, we analyzed the phlebotomy tube usage data at the Zhongshan Hospital, Fudan University, to show potential inefficiencies with phlebotomy tube usage.

Methods

Data of 984,078 patients with 1,408,175 orders and 4,622,349 total phlebotomy tubes were collected during years 2018-2021. Data of different patient types were compared. Furthermore, we assessed the data from subspecialty and test levels to explore the factors influencing the increase in phlebotomy tube usage.

Results

We observed an overall 8% increase in both the mean number of tubes used and blood loss per order over the past 4 years. The mean blood loss per day for intensive care unit (ICU) patients was 18.7 ml (maximum 121.6 ml), which was well under the 200 ml/day threshold. However, the maximum number of tubes used reached more than 30 tubes/day.

Conclusions

The 8% increase of phlebotomy tubes over 4 years should alarm laboratory managements, as tests offered are expected to increase in the future. Importantly, the whole healthcare community needs to work together to solve this problem with more creative solutions.

Behavioural change interventions encouraging clinicians to reduce carbon emissions in clinical activity: a systematic review

BACKGROUND

Clinical activity accounts for 70-80% of the carbon footprint of healthcare. A critical component of reducing emissions is shifting clinical behaviour towards reducing, avoiding, or replacing carbon-intensive healthcare. The objective of this systematic review was to find, map and assess behaviour change interventions that have been implemented in healthcare settings to encourage clinicians to reduce greenhouse gas emissions from their clinical activity.

METHODS

Studies eligible for inclusion were those reporting on a behaviour change intervention to reduce carbon emissions via changes in healthcare workplace behaviour. Six databases were searched in November 2021 (updated February 2022). A pre-determined template was used to extract data from the studies, and risk of bias was assessed. The behaviour change techniques (BCTs) used in the interventions were coded using the BCT Taxonomy.

RESULTS

Six full-text studies were included in this review, and 14 conference abstracts. All studies used a before-after intervention design. The majority were UK studies (n = 15), followed by US (n = 3) and Australia (n = 2). Of the full-text studies, four focused on reducing the emissions associated with anaesthesia, and two aimed at reducing unnecessary test ordering. Of the conference abstracts, 13 focused on anaesthetic gas usage, and one on respiratory inhalers. The most common BCTs used were social support, salience of consequences, restructuring the physical environment, prompts and cues, feedback on outcome of behaviour, and information about environmental consequences. All studies reported success of their interventions in reducing carbon emissions, prescribing, ordering, and financial costs; however, only two studies reported the magnitude and significance of their intervention's success. All studies scored at least one item as unclear or at risk of bias.

CONCLUSION

Most interventions to date have targeted anaesthesia or pathology test ordering in hospital settings. Due to the diverse study outcomes and consequent inability to pool the results, this review is descriptive only, limiting our ability to conclude the effectiveness of interventions. Multiple BCTs were used in each study but these were not compared, evaluated, or used systematically. All studies lacked rigour in study design and measurement of outcomes.

REVIEW REGISTRATION

The study was registered on Prospero (ID number CRD42021272526) (Breth-Petersen et al., Prospero 2021: CRD42021272526).

Embedding education into clinical laboratory professional training to foster sustainable development and greener practice

It has become apparent that the climate crisis is reaching critical levels and Governments and key organisations are recognising the need for change. A review of current literature reveals very little published research concerning the impact of clinical laboratory practice on the carbon footprint of healthcare. For a clinical laboratory to become more environmentally sound, key target areas of focus are required. With sustainability becoming a key consideration for course development, employing educational principles such as Education for Sustainable Development (ESD) in the form of Sustainability in Quality Improvement (SusQI), Quality Improvement objectives can be met, while benefitting the patient and the environmental impact of organisation.

Exploring the Integration of Environmental Impacts in the Cost Analysis of the Pilot MEL-SELF Trial of Patient-Led Melanoma Surveillance

AIMS

Human health is intrinsically linked with planetary health. But planetary resources are currently being degraded and this poses an existential threat to human health and the sustainability of our healthcare systems. The aims of this study were to (1) describe an approach to integrate environmental impacts in a cost analysis; and (2) demonstrate this approach by estimating select environmental impacts alongside traditional health system and other costs using the example of the pilot MEL-SELF randomised controlled trial of patient-led melanoma surveillance.

METHODS

Economic costs were calculated alongside a randomised trial using standard cost analysis methodology from a societal perspective. Environmental impacts were calculated using a type of carbon footprinting methodology called process-based life cycle analysis. This method considers three scopes of carbon emissions: Scope 1, which occur directly from the intervention; Scope 2, which occur indirectly from the intervention's energy use; and Scope 3, which occur indirectly because of the value chain of the intervention. In this study we only included emissions from patient transport to attend their melanoma clinic over the study period of 6 months.

RESULTS

The environmental impact per participant across allocated groups for patient transport to their melanoma clinic was estimated to be 10 kg carbon dioxide equivalent. Economic costs across the allocated groups indicated substantial health system costs, out-of-pocket costs, and productivity losses associated with melanoma surveillance. The largest cost contributor was health system costs, and the most expensive category of health system cost was hospital admission.

CONCLUSION

Calculating environmental impacts is worthwhile and feasible within a cost analysis framework. Further work is needed to address outstanding conceptual and practical issues so that a comprehensive assessment of environmental impacts can be considered alongside economic costs in health technology assessments.

HealthcareLCA: an open-access living database of health-care environmental impact assessments

Anthropogenic environmental change negatively effects human health and is increasing health-care system demand. Paradoxically, the provision of health care, which itself is a substantial contributor to environmental degradation, is compounding this problem. There is increasing willingness to transition towards sustainable health-care systems globally and ensuring that strategy and action are informed by best available evidence is imperative. In this Personal View, we present an interactive, open-access database designed to support this effort. Functioning as a living repository of environmental impact assessments within health care, the HealthcareLCA database collates 152 studies, predominantly peer-reviewed journal articles, into one centralised and publicly accessible location, providing impact estimates (currently totalling 3671 numerical values) across 1288 health-care products and processes. The database brings together research generated over the past two decades and indicates exponential field growth.

Incorporating carbon into health care: adding carbon emissions to health technology assessments

At the UN Climate Change Conference 26 in Glasgow, 50 countries committed to low-carbon health services, with 14 countries further committing to net-zero carbon health services by 2050. Reaching this target will require decision makers to include carbon emissions when evaluating new and existing health technologies (tests and treatments). There is currently, however, a scarcity of data on the carbon footprint of health-care interventions, nor any means for decision makers to include and consider carbon emission health-care assessments. We therefore investigated how to integrate carbon emissions calculated by environmental life cycle assessment (LCA) into health technology assessments (HTA). HTAs are extensively used in developing clinical and policy guidelines by individual public or private payers, and by government organisations. In the first section we explain the methodological differences between environmentally extended input-output and process-based LCA. The second section outlines ways in which carbon emissions calculated by LCA could be integrated with HTAs, recognising that HTAs are done in several ways by different jurisdictions. International effort and processes will be needed to ensure that robust and comprehensive carbon footprints of commonly used health-care products are freely available. The technical and implementation challenges of incorporating carbon emissions into HTAs are considerable, but not unsurmountable. Our aim is to lay foundations for meeting these challenges.

Towards NHS Zero: greener gastroenterology and the impact of virtual clinics on carbon emissions and patient outcomes. A multisite, observational, cross-sectional study

Objective

The National Health Service (NHS) produces more carbon emissions than any public sector organisation in England. In 2020, it became the first health service worldwide to commit to becoming carbon net zero, the same year as the COVID-19 pandemic forced healthcare systems globally to rapidly adapt service delivery. As part of this, outpatient appointments became largely remote. Although the environmental benefit of this change may seem intuitive the impact on patient outcomes must remain a priority. Previous studies have evaluated the impact of telemedicine on emission reduction and patient outcomes but never before in the gastroenterology outpatient setting.

Method

2140 appointments from general gastroenterology clinics across 11 Trusts were retrospectively analysed prior to and during the pandemic. 100 consecutive appointments during two periods of time, from 1 June 2019 (prepandemic) to 1 June 2020 (during the pandemic), were used. Patients were telephoned to confirm the mode of transport used to attend their appointment and electronic patient records reviewed to assess did-not-attend (DNA) rates, 90-day admission rates and 90-day mortality rates.

Results

Remote consultations greatly reduced the carbon emissions associated with each appointment. Although more patients DNA their remote consultations and doctors more frequently requested follow-up blood tests when reviewing patients face-to-face, there was no significant difference in patient 90-day admissions or mortality when consultations were remote.

Conclusion

Teleconsultations can provide patients with a flexible and safe means of being reviewed in outpatient clinics while simultaneously having a major impact on the reduction of carbon emissions created by the NHS.

Planetary Health and Hospitals' Contribution-A Scoping Review

Climate change is one of the greatest global threats for planetary and human health. This leads to new challenges for public health. Hospitals emit large amounts of greenhouse gases (GHG) in their healthcare delivery through transportation, waste and other resources and are considered as key players in reducing healthcare's environmental footprint. The aim of this scoping review is to provide the state of research on hospitals' carbon footprint and to determine their contribution to mitigating emissions. We conducted a systematic literature search in three databases for studies related to measurement and actions to reduce GHG emissions in hospitals. We identified 21 studies, the oldest being published in 2012, and the most recent study in 2021. Eight studies focused on GHG emissions hospital-wide, while thirteen studies addressed hospital-based departments. Climate actions in the areas of waste and transportation lead to significant reductions in GHG emissions. Digital transformation is a key factor in implementing climate actions and promoting equity in healthcare. The increasing number of studies published over time indicates the importance of the topic. The results suggest a need for standardization of measurement and performance indicators on climate actions to mitigate GHG emissions.

Health, financial and environmental impacts of unnecessary vitamin D testing: a triple bottom line assessment adapted for healthcare

OBJECTIVE

To undertake an assessment of the health, financial and environmental impacts of a well-recognised example of low-value care; inappropriate vitamin D testing.

DESIGN

Combination of systematic literature search, analysis of routinely collected healthcare data and environmental analysis.

SETTING

Australian healthcare system.

PARTICIPANTS

Population of Australia.

OUTCOME MEASURES

We took a sustainability approach, measuring the health, financial and environmental impacts of a specific healthcare activity. Unnecessary vitamin D testing rates were estimated from best available published literature; by definition, these provide no gain in health outcomes (in contrast to appropriate/necessary tests). Australian population-based test numbers and healthcare costs were obtained from Medicare for vitamin D pathology services. Carbon emissions in kg CO2e were estimated using data from our previous study of the carbon footprint of common pathology tests. We distinguished between tests ordered as the primary test and those ordered as an add-on to other tests, as many may be done in conjunction with other tests. We conducted base case (8% being the primary reason for the blood test) and sensitivity (12% primary test) analyses.

RESULTS

There were a total of 4 457 657 Medicare-funded vitamin D tests in 2020, on average one test for every six Australians, an 11.8% increase from the mean 2018-2019 total. From our literature review, 76.5% of Australia's vitamin D tests provide no net health benefit, equating to 3 410 108 unnecessary tests in 2020. Total costs of unnecessary tests to Medicare amounted to >$A87 000 000. The 2020 carbon footprint of unnecessary vitamin D tests was 28 576 kg (base case) and 42 012 kg (sensitivity) CO2e, equivalent to driving ~160 000-230 000 km in a standard passenger car.

CONCLUSIONS

Unnecessary vitamin D testing contributes to avoidable CO2e emissions and healthcare costs. While the footprint of this example is relatively small, the potential to realise environmental cobenefits by reducing low-value care more broadly is significant.

Carbon Emissions from Overuse of U.S. Health Care: Medical and Ethical Problems

The United States health care industry is the second largest in the world, expending an estimated 479 million metric tons (MMT) of carbon dioxide per year, nearly 8 percent of the country's total emissions. The importance of carbon reduction in health care is slowly being accepted. However, efforts to "green" health care are incomplete since they generally focus on buildings and structures. Yet hospital care and clinical service sectors contribute the most carbon dioxide within the U.S. health care industry, with structures/equipment and pharmaceuticals ranking as the third and fourth highest emitters in the industry. Given the magnitude of health care carbon emissions-and the paucity of attention to the carbon of hospital care and clinical services-this essay identifies overuse of health care as a health threat with serious ethical implications, offers a data-driven action plan for carbon reduction in health care, and provides practical suggestions for more sustainable health care delivery in the United States.

Everyone's a winner if we test less: the CODA action plan

In this era of 'Choosing Wisely,' we present a four-step action plan to reduce unnecessary pathology testing and the associated patient harm (blood loss through repeated phlebotomy), economic cost and environmental impact. The authors are experts from the CODA group; a medical education and health-promotion charity that aims to build on the Choosing Wisely initiative to provide meaningful and sustainable actions to reduce the carbon footprint of healthcare, globally. Pathology testing is expensive and carbon-intensive, with as many as half of all tests being not clinically indicated. Reducing unnecessary testing is the only effective way to decrease the carbon footprint and other associated costs, as opportunities to reuse and recycle pathology specimens are limited. The four key steps for action are (i) auditing local practice; (ii) defining unnecessary testing including developing a clinical guideline for rational ordering; (iii) educating stakeholders; and (iv) measuring the impact of the intervention through re-audit. This proven method is designed to be used in any healthcare setting around the world; having a small group of passionate 'champions' is thought to be as important as strong clinical governance and more important than access to sophisticated equipment. Electronic medical record systems and other technological solutions offer new ways to help establish a sustainability mindset and reduce unnecessary testing. The Codachange.org/coda-earth/ website provides a dynamic crowdsourcing platform through which we can collectively learn to meet the diverse needs of our international medical community. Self-reported outcomes are gamified through collaborative feedback, amplification via social media and the ability to earn rewards, be uploaded to the CODA website, or added to the template as a success story. By combining our existing local networks with the emerging international CODA community, we can initiate meaningful change now and enter the era of environmental stewardship.

The carbon footprint of hospital diagnostic imaging in Australia

BACKGROUND

Pathology testing and diagnostic imaging together contribute 9% of healthcare's carbon footprint. Whilst the carbon footprint of pathology testing has been undertaken, to date, the carbon footprint of the four most common imaging modalities is unclear.

METHODS

We performed a prospective life cycle assessment at two Australian university-affiliated health services of five imaging modalities: chest X-ray (CXR), mobile chest X-ray (MCXR), computerised tomography (CT), magnetic resonance imaging (MRI) and ultrasound (US). We included scanner electricity use and all consumables and associated waste, including bedding, imaging contrast, and gloves. Analysis was performed using both attributional and consequential life cycle assessment methods. The primary outcome was the greenhouse gas footprint, measured in carbon dioxide equivalent (CO₂e) emissions.

FINDINGS

Mean CO₂e emissions were 17·5 kg/scan for MRI; 9·2 kg/scan for CT; 0·8 kg/scan for CXR; 0·5 kg/scan for MCXR; and 0·5 kg/scan for US. Emissions from scanners from standby energy were substantial. When expressed as emissions per additional scan (results of consequential analysis) impacts were lower: 1·1 kg/scan for MRI; 1·1 kg/scan for CT; 0·6 kg/scan for CXR; 0·1 kg/scan for MCXR; and 0·1 kg/scan for US, due to emissions from standby power being excluded.

INTERPRETATION

Clinicians and administrators can reduce carbon emissions from diagnostic imaging, firstly by reducing the ordering of unnecessary imaging, or by ordering low-impact imaging (X-ray and US) in place of high-impact MRI and CT when clinically appropriate to do so. Secondly, whenever possible, scanners should be turned off to reduce emissions from standby power. Thirdly, ensuring high utilisation rates for scanners both reduces the time they spend in standby, and apportions the impacts of the reduced standby power of a greater number of scans. This therefore reduces the impact on any individual scan, maximising resource efficiency.

FUNDING

Healthy Urban Environments (HUE) Collaboratory of the Maridulu Budyari Gumal Sydney Partnership for Health, Education, Research and Enterprise MBG SPHERE. The National Health and Medical Research Council (NHMRC) PhD scholarship.