Diagnostic Stewardship Is Environmental Stewardship Open Access

Climate change increases the risk of heat-related illness, infections, trauma, mental health disorders, and malnutrition. These risks disproportionately affect vulnerable and marginalized populations already burdened by health care inequity.¹  The US health care system is responsible for approximately 8.5% of domestic greenhouse gas (GHG) emissions.²  Consequently, systemic decarbonization and individual actions within the health care sector are urgently needed. Physicians are concerned about the negative health impacts of climate change and are seeking opportunities to combat the problem in daily practice.^3 ,4  Calls by trainees and medical societies to increase climate health education present graduate medical education (GME) programs with the challenge of incorporating such education into their programs.^3 ,5  Diagnostic stewardship presents an opportunity to reduce avoidable environmental costs of health care in daily practice by eliminating unnecessary or inappropriate testing. In this Perspectives article, we propose that medical educators highlight the intersecting goals of diagnostic stewardship and environmental stewardship, and we suggest opportunities for GME programs to implement concurrent diagnostic and environmental stewardship efforts in clinical, research, and advocacy contexts.

The US health care system has the highest absolute and per capita climate footprint (emissions of carbon dioxide [CO₂], methane, and nitrous oxide) of any country’s health care system.^2 ,6  Based on a national-level model of US health care sector emissions, approximately 80% of US health care greenhouse gas (GHG) emissions result from the goods and services utilized by the health system, including pharmaceuticals, chemicals, medical supplies, and waste management.^2 ,7  Despite high health care–associated waste production, there is a paucity of published data describing the contribution of specific health care departments, laboratory tests, and other health care services toward overall health care waste. Studies have quantified the CO₂ emissions generated by the consumable laboratory materials used in surgical procedures⁸  and medical imaging,⁹  and an Australian-based study found emissions reductions with a hospital-wide campaign to reduce unnecessary daily lab testing.¹⁰ 

Unnecessary testing occurs commonly in health care. Studies suggest up to 50% to 70% of tests may be avoidable.^11 -13  Results from unnecessary tests can lead to further diagnostic overuse and unnecessary treatments. On an individual patient level, diagnostic overuse results in avoidable consequences ranging from mild discomfort to serious adverse events, including death.¹⁴  Financial costs of diagnostic and treatment overuse impact individual patients and the entire health care system, with estimates suggesting that low-value care or overtreatment results in approximately $100 billion in excess US health care spending annually.¹⁵  Low-income patients are more vulnerable to individual financial harms of overuse, and some evidence suggests that minoritized patients may receive low-value care more often than White patients.¹⁶  Quantifying specific environmental costs of diagnostic and treatment overuse is challenging; emerging evidence suggests substantial carbon costs result from unnecessary tests.^17 ,18  In these studies, most emissions resulted from generating consumables and laboratory test processing, so reducing unnecessary testing through diagnostic stewardship offers the potential benefit of decreasing health care–generated GHG emissions while also decreasing patient and health care system costs.

The World Health Organization (WHO) maintains that diagnostic stewardship “…begins with the practice and procedures that guide specimen selection… and it extends subsequently to how results are reported and interpreted and then used to guide patient management.”¹⁹  Considered by the Centers for Disease Control and Prevention (CDC) as a method to reduce diagnostic error, diagnostic stewardship prioritizes “the right test, for the right patient, to prompt the right action.”²⁰  Diagnostic stewardship incorporates evidence-based approaches and behavioral economics to optimize diagnostic use, and it is typically achieved through interdisciplinary teamwork.²¹  Diagnostic stewardship has been used to decrease a variety of inappropriate tests such as unnecessary daily labs and inappropriate Clostridioides difficile testing.²²  Studies also demonstrate reductions in utilization of urine cultures and blood cultures using diagnostic stewardship initiatives.^23 -25 

Trainees and program directors believe that climate change education should be incorporated into clinical settings, and many prefer focusing efforts on reducing medical waste.^3 ,26  GME programs are an ideal setting to incorporate diagnostic stewardship practices because trainees are integral to daily patient care and are positioned to shape the future of clinical practice.²⁷  Bedside teaching remains a foundation of GME, and diagnostic stewardship can be applied at the bedside during daily rounds or clinic visits when medical teams develop diagnostic plans. It requires minimal additional time for teams to discuss the environmental impact of diagnostic testing, including the positive impact of reductions in overuse. Patient encounters provide a high-yield opportunity to initiate a culture shift in trainees toward viewing environmental stewardship as a professional duty alongside diagnostic stewardship and antimicrobial stewardship.²⁸ 

Adherence to consensus guidelines that incorporate best-available evidence with clinical expertise can support the reduction of unnecessary medical testing or treatments. Studies promoting adherence to the Infectious Diseases Society of America guideline for streptococcal pharyngitis reduced unnecessary streptococcal pharyngitis testing in ambulatory and emergency settings.^29 ,30  Another study implemented a guideline-based electronic ordering and monitoring system for blood transfusions that resulted in increased compliance with guidelines and a decreased number of blood transfusions without increasing length of stay or mortality.³¹  These reductions in unnecessary testing or treatments likely contribute toward a more environmentally sustainable health care system. Gaps in existing evidence quantifying environmental savings of specific guideline-based interventions create research opportunities for trainees (Table). A report published by the CDC’s Division of Healthcare Quality Promotion recognizes a need to develop methods that quantify the health benefits of minimizing inappropriate medical testing through diagnostic stewardship.³⁷  Training programs in which evidence-based, high-value care is promoted, are excellent settings to study environmental savings of specific interventions.

Quality improvement (QI) is an Accreditation Council for Graduate Medical Education (ACGME) requirement and an opportunity to implement diagnostic stewardship initiatives and demonstrate the environmental savings in practice (Table). Institutional antimicrobial stewardship programs and diagnostic stewardship programs can serve as partners to collect and analyze data on resource use and institutional guideline adherence. Life cycle assessments, which can be used to quantify the environmental impact of medical tests, could be incorporated into resident QI projects, generating valuable data to inform system-wide sustainability efforts.³⁸  Trainees and training programs can partner with local organizations and institutional leadership to better understand resource use and advocate for policies that support diagnostic stewardship and environmental sustainability in health care. Trainees can also join organizations that conduct research and advocate for high-quality care and reduced health care waste on a national and global level (eg, Health Care Without Harm, Physicians for Social Responsibility).

As health care practices within hospitals and clinics contribute to climate change and affect patients’ health, GME programs can begin to address the environmental footprint within their own institutions. Concurrent diagnostic and environmental stewardship can be incorporated into medical education programs without excessive burden. Specifically, bedside teaching can draw attention to waste associated with unnecessary testing and promote a culture of environmental stewardship. Optimal interventions and environmental savings can be identified through QI and research studies to guide system-wide recommendations for waste reduction. Programs can implement these strategies as part of climate health education and efforts toward health care sustainability.

* Denotes co-first authors.

Funding: This work was partially supported by the National Institute of Allergy and Infectious Diseases T32AI055433 awarded to Kristen Bastug, MD.