2. Advancing planetary health as an aim for healthcare improvement

A health system that advances planetary health requires a systems-thinking approach, based on four main principles, contributing to tackling the current crisis of value and purpose that affects health systems worldwide (Larsson et al., Reference Larsson, Clawson and Howard2023): decreasing the demand for health services through health promotion and disease prevention; pursuing the delivery of appropriate care; abating the overall environmental footprint of health services (MacNeill et al., Reference MacNeill, McGain and Sherman2021); endorsing planetary health action across other sectors and the overall society (Karliner et al., Reference Karliner, Roschnik, Boyd, Ashby and Steele2021) (Figure 1).

Figure 1. A revised quadruple aim for healthcare improvement, centered on the advancement of planetary health.

In relation to the first principle, evidence-based health promotion and disease prevention programs, powered by engaging stakeholders from multiple sectors (Claflin & Aloia, Reference Claflin and Aloia2010), alleviate disease burden (Bandosz et al., Reference Bandosz, Ahmadi-Abhari, Guzman-Castillo, Pearson-Stuttard, Collins, Whittaker, Shipley, Capewell, Brunner and O'Flaherty2020; Rasella et al., Reference Rasella, Harhay, Pamponet, Aquino and Barreto2014; Soltani et al., Reference Soltani, Saraf-Bank, Basirat, Salehi-Abargouei, Mohammadifard, Sadeghi, Khosravi, Fadhil, Puska and Sarrafzadegan2021; Wang et al., Reference Wang, Hu, Zhao, Kuang, Zhao, Liu and Zhu2021) and, consequently, its environmental footprint (Bi & Hansen, Reference Bi and Hansen2018). Smart governance for health and wellbeing provides the framework for such an intense cross-sectoral cooperation to thrive (Kickbusch & Gleicher, Reference Kickbusch and Gleicher2012). Additionally, 16.4% of the world population is projected to be 65 years or older by 2050, nearly doubling the current share (Gerland et al., Reference Gerland, Hertog, Wheldon, Kantorova, Gu, Gonnella, Williams, Zeifman, Bay, Castanheira, Kamiya, Bassarsky, Gaigbe-Togbe and Spoorenberg2022), which is likely to push demand for health services even further. Investing in public health interventions is deemed an effective way to put a cap on this process, thus allowing health systems to effectively deliver services still needed, while curbing not only their attributable footprint on natural systems but also economic, social and personal costs (Masters et al., Reference Masters, Anwar, Collins, Cookson and Capewell2017; McDaid, Reference McDaid2018). Despite that, across countries belonging to the Organisation for Economic Co-operation and Development, preventive care expenditure accounted for just 0.24% of gross domestic product and 2.59% of current health expenditure in 2019, on average (OECD, 2023). Interventions addressing tobacco, meat consumption, obesity, and air pollution are projected to save approximately 1.5 gigatons of CO_2e from 2014 to 2050 (Karliner et al., Reference Karliner, Roschnik, Boyd, Ashby and Steele2021). The push for integrated public health policies must address the challenges presented by short-sighted public systems and private healthcare systems in which diseases can unfortunately be perceived as revenue generators (McDaid, Reference McDaid2018; Missoni & Galindo, Reference Missoni and Galindo2020).

The second principle consists in delivering appropriate healthcare that responds to health needs according to evidence-based practice. This entails the cessation of superfluous exams and prescriptions (Kherad & Carneiro, Reference Kherad and Carneiro2022), as well as service delivery in the most efficient setting. Hospital care, which is intrinsically energy- and resource-intensive, has a larger carbon footprint than primary care (Malik et al., Reference Malik, Lenzen, McAlister and McGain2018; Nicolet et al., Reference Nicolet, Mueller, Paruta, Boucher and Senn2022; Pichler et al., Reference Pichler, Jaccard, Weisz and Weisz2019; Tennison et al., Reference Tennison, Roschnik, Ashby, Boyd, Hamilton, Oreszczyn, Owen, Romanello, Ruyssevelt, Sherman, Smith, Steele, Watts and Eckelman2021). Hence, striving to limit hospitalizations through appropriate care, ensuring accessibility and continuity across primary and community care settings, within the framework of secondary and tertiary prevention community-based programs, is in turn beneficial to the environment, as opposed to frequent hospital accesses, resulting from inadequate and chaotic care. Healthcare systems with Beveridge models and ex-ante reimbursement strategies tend to favor appropriate care, given the need to contain expenditure, whereas it may undermine profitability in private health care. Professionals' culture, specific patient requests, conflicts of interest, and care fragmentation all have a role in over-prescribing and over-treatment (Missoni & Galindo, Reference Missoni and Galindo2020).

The third principle is concerned with reducing the environmental impact of the high-value health services still needed to meet population health needs. The main production sectors responsible for that encompass energy supply, operational emissions, manufacturing, agriculture, and transport (Health Care Without Harm, 2019). Assessments of the healthcare environmental impact have been conducted on national and global scales, much as further methodological improvements are warranted (Eckelman et al., Reference Eckelman, Romanello, Sherman and Watts2020b; Steenmeijer et al., Reference Steenmeijer, Rodrigues, Zijp and der Loop2022). Globally, the environmental footprint of health care amounts to 4.4% of greenhouse gas emissions, 2.8% of particulate matter, 3.4% of nitrogen oxides, and 3.6% of sulfur dioxide (Lenzen et al., Reference Lenzen, Malik, Li, Fry, Weisz, Pichler, Chaves, Capon and Pencheon2020).

Lastly, health systems are in a strong position to steer societies and economies toward planetary health goals. Intensive climate action would lead to large health co-benefits (Campbell-Lendrum et al., Reference Campbell-Lendrum, Neville, Schweizer and Neira2023; Whitmee et al., Reference Whitmee, Green, Belesova, Hassan, Cuevas, Murage, Picetti, Clercq-Roques, Murray, Falconer, Anton, Reynolds, Waddington, Hughes, Spadaro, Jaber, Saheb, Campbell-Lendrum, Cortés-Puch and Haines2024) and thoroughly accomplish the system's mission. Health systems with a strong commitment to environmental sustainability can exert a guidance role, influencing other companies and the civil society, while leveraging their remarkable purchasing power (Howard et al., Reference Howard, MacNeill, Hughes, Alqodmani, Charlesworth, de Almeida, Harris, Jochum, Maibach, Maki, McGain, Miller, Nirmala, Pencheon, Robertson, Sherman, Vipond, Yin and Montgomery2023). Societies and economies, in turn, striving to operate within planetary boundaries, contribute to the health care's own sustainability and human health goals, as social and economic determinants improve and any-grade suppliers decarbonize. This influence is integral to a comprehensive process to augment and emphasize connections between health and other sectors.

3. How the planetary health goal contributes to other aims

The proposed aim of advancing planetary health contributes to each of the other interdependent aims (Bodenheimer & Sinsky, Reference Bodenheimer and Sinsky2014) (Figure 2). In fact, planetary health encompasses the health of human civilization, thus embracing the original aim of improving population health, while further expanding on it and acknowledging its being intertwined with the health of natural systems (Whitmee et al., Reference Whitmee, Haines, Beyrer, Boltz, Capon, de Souza Dias, Ezeh, Frumkin, Gong, Head, Horton, Mace, Marten, Myers, Nishtar, Osofsky, Pattanayak, Pongsiri, Romanelli and Yach2015).

Figure 2. How advancing planetary health contributes to other healthcare improvement aims.

While equity was proposed as an aim for healthcare improvement (Nundy et al., Reference Nundy, Cooper and Mate2022), applying an equity and social justice lens to issues being addressed is a cornerstone of planetary health. This concept was proposed in 2023 by Rockström et al., as a set of safe and just Earth system boundaries (ESBs) (Rockström et al., Reference Rockström, Gupta, Qin, Lade, Abrams, Andersen, Armstrong McKay, Bai, Bala, Bunn, Ciobanu, DeClerck, Ebi, Gifford, Gordon, Hasan, Kanie, Lenton, Loriani and Zhang2023). These boundaries aim to maintain the resilience and stability of the Earth system (safe ESBs) while minimizing human exposure to significant harm from Earth system changes, a necessary but not sufficient condition for justice (Rockström et al., Reference Rockström, Gupta, Qin, Pedde, Broadgate and Warszawski2021). The consideration of health equity is linked to the widespread exposure to significant harm from planetary crises, with greater impacts on vulnerable populations, exacerbating existing inequities in disease burdens and premature mortality, and potentially leading to social unrest (Friel, Reference Friel2022; Intergovernmental Panel on Climate Change (IPCC), 2023). As a matter of fact, the brunt of environmental disruptions is primarily felt by low-income countries and individuals as well as racial minorities, who contribute less to causing them (Deivanayagam et al., Reference Deivanayagam, English, Hickel, Bonifacio, Guinto, Hill, Huq, Issa, Mulindwa, Nagginda, de Sato, Selvarajah, Sharma and Devakumar2023; Gore, Reference Gore2020; Hickel et al., Reference Hickel, O'Neill, Fanning and Zoomkawala2022; Lenton et al., Reference Lenton, Xu, Abrams, Ghadiali, Loriani, Sakschewski, Zimm, Ebi, Dunn, Svenning and Scheffer2023; Vicedo-Cabrera et al., Reference Vicedo-Cabrera, Scovronick, Sera, Royé, Schneider, Tobias, Astrom, Guo, Honda, Hondula, Abrutzky, Tong, de Sousa Zanotti Stagliorio Coelho, Saldiva, Lavigne, Correa, Ortega, Kan, Osorio and Gasparrini2021). A foundation that ensures minimum access to basic needs, including health, for all humans, alongside a safe and just ESB ceiling of maximum allowed human pressure on biophysical domains, could constitute a safe and just ‘corridor’ over time (Rockström et al., Reference Rockström, Gupta, Qin, Lade, Abrams, Andersen, Armstrong McKay, Bai, Bala, Bunn, Ciobanu, DeClerck, Ebi, Gifford, Gordon, Hasan, Kanie, Lenton, Loriani and Zhang2023). Hence, the uneven distribution of the effects of planetary crises calls for just and equitable solutions to advance planetary health.

Planetary health interventions are also associated with cost reduction. Evidence suggests that both improving the environmental sustainability of healthcare facilities and disease prevention and health promotion lead to cost savings (Ashton et al., Reference Ashton, Schröder-Bäck, Clemens, Dyakova, Stielke and Bellis2020; Masters et al., Reference Masters, Anwar, Collins, Cookson and Capewell2017; McCullough, Reference McCullough2018; NHS England and NHS Improvement, 2022; Pisters et al., Reference Pisters, Bien, Dankner, Rubinstein and Sheriff2017; Storz, Reference Storz2020; Sullivan et al., Reference Sullivan, Petit, Reiter, Westrick, Hu, Dunn, Gulack, Shah, Dsida and Raval2023).

In terms of patient experience, several associations are highlighted. Patient experience is associated with preventive care (Doyle et al., Reference Doyle, Lennox and Bell2013) and nature exposure within the healthcare context (Tseung et al., Reference Tseung, Verweel, Harvey, Pauley and Walker2022; Weerasuriya et al., Reference Weerasuriya, Henderson-Wilson and Townsend2018). For example, having access to hospital green spaces significantly improves overall satisfaction with the facility, a sentiment shared by both patients and staff members alike (Kim et al., Reference Kim, Hwang, Lee and Corser2015; O'Hara et al., Reference O'Hara, Miller, Spinks, Seifert, Mills and Tuininga2022; Sadatsafavi et al., Reference Sadatsafavi, Walewski and Taborn2015).

Reducing unnecessary visits and exams and green delivery of drugs also enhance patient experience (El-Hallal et al., Reference El-Hallal, Shah, Nath, Eksambe, Theroux, Amlicke, Steele, Krief and Kothare2021; Kelendar et al., Reference Kelendar, Faisal and Mohammed2020; NHS, n.d.; Rizan et al., Reference Rizan, Das, Low, Harden, Groves, Flaherty, Welland and Bhutta2019). Patients aware of planetary health issues might find comfort in receiving care in facilities transitioning to environmentally sustainable processes.

Pursuing the promotion of planetary health also affects the wellbeing of health professionals. Accessing green spaces and reducing workload by avoiding unwarranted care are suggested as positive drivers of health and wellbeing in the healthcare community (Centre for Sustainable Healthcare, 2020; Marusic, Reference Marusic2023).

The climate breakdown is already impacting health in a myriad of ways, including by leading to death and illness from increasingly frequent extreme weather events, such as heatwaves, storms, and floods, the disruption of food systems, increases in zoonoses and food-, water-, and vector-borne diseases, and mental health issues. Health professionals are at the forefront of responding to these health impacts, and their own wellbeing is also affected by the changing climate. They are exposed to the same health risks as the general population, but they also face additional stressors, such as increased workload, longer working hours, and exposure to traumatic events (Agache et al., Reference Agache, Sampath, Aguilera, Akdis, Akdis, Barry, Bouagnon, Chinthrajah, Collins, Dulitzki, Erny, Gomez, Goshua, Jutel, Kizer, Kline, LaBeaud, Pali-Schöll, Perrett and Nadeau2022). As with patients, professionals with environmental values may find sustainable work practices more rewarding, easing potential discomfort and anxiety generated by the environmental footprint of their working practices. Further links, in this space, can be identified by reviewing the Covid-19 experience. Indeed, Covid-19 is regarded as an Anthropocene disease (O'Callaghan-Gordo & Antó, Reference O'Callaghan-Gordo and Antó2020), spurred by the degraded status of planetary health (Myers & Frumkin, Reference Myers and Frumkin2020). It heavily strained healthcare systems worldwide, with consequences being felt in terms of healthcare professionals' mental health, as well (Aymerich et al., Reference Aymerich, Pedruzo, Pérez, Laborda, Herrero, Blanco, Mancebo, Andrés, Estévez, Fernandez, Salazar de Pablo, Catalan and González-Torres2022; Galanis et al., Reference Galanis, Vraka, Fragkou, Bilali and Kaitelidou2021). Protecting the health of nature and humans through large-scale solutions may help avoid similar disastrous events and their wide-ranging aftermath (Myers & Frumkin, Reference Myers and Frumkin2020).

4. Pathways for health systems to advance planetary health

Aiming to foster planetary health as a health system operationally translates into a series of intertwined pathways (Figure 3).

Figure 3. Main principles and pathways to advancing planetary health as the leading aim for quality improvement in healthcare systems.

With regard to disease prevention and preventable disease burden, enablers can be identified in strong political dedication to public health priorities, effective institutional structures to guide and organize essential public health functions (EPHFs), multisectoral responsibility, assessment of the provision of EPHFs, sufficient workforce and funding (WHO, 2022a, 2022b). Given the increasing urbanization and the need to enhance disease prevention at the city level, political engagement, addressing urban determinants of health, policy debate and institutional reforms are demanded for the shift to health-promoting cities (WHO, 2020).

To increase care appropriateness, active multi-component initiatives proved their effectiveness in reducing unnecessary care (George & Joshi, Reference George and Joshi2022; Rose et al., Reference Rose, Crosbie and Stewart2021). Effective elements, either as single or multi-interventions, include care pathways, educational interventions, organizational culture, audit and feedback and reminders (Pereira et al., Reference Pereira, Silva, Carvalho, Zanghelini and Barreto2022). Policy statements and guidelines from associations, patient and physician education, leadership and peer support feature among the facilitators of the patient–planetary health co-benefit prescribing framework (Redvers et al., Reference Redvers, Wright, Hartmann-Boyce and Tonkin-Crine2023).

Pathways toward decarbonized and low-pollution healthcare broadly encompass green energy supply across both own operations and supply chain, decline in energy demand, professionals' behaviors change, shift to low-impact drugs and devices (Andersen et al., Reference Andersen, Nielsen and Sherman2023; Blom et al., Reference Blom, Eissa, Mattijsen, Sana, Haines and Whitmee2024; Keil et al., Reference Keil, Viere, Helms and Rogowski2023; Pernigotti et al., Reference Pernigotti, Stonham, Panigone, Sandri, Ferri, Unal and Roche2021), sustainable travel, telemedicine, optimal waste management, nature-based solutions, and low-impact food supply chains (Karliner et al., Reference Karliner, Roschnik, Boyd, Ashby and Steele2021; Purohit et al., Reference Purohit, Smith and Hibble2021). Promoting gender balance in healthcare management and leadership generally, reallocating environmentally damaging investments to planetary health solutions (Howard et al., Reference Howard, MacNeill, Hughes, Alqodmani, Charlesworth, de Almeida, Harris, Jochum, Maibach, Maki, McGain, Miller, Nirmala, Pencheon, Robertson, Sherman, Vipond, Yin and Montgomery2023), embedding carbon emissions into existing priority processes (Bhopal & Norheim, Reference Bhopal and Norheim2021), all fall under the scope of returning healthcare to a healthy balance with natural systems. In addition, integrating environmental information into Health Technology Assessment could help refine health system decision making about technologies or interventions. These decisions would be based on data on environmental effects as well as clinical outcomes and costs (Pinho-Gomes et al., Reference Pinho-Gomes, Yoo, Allen, Maiden, Shah and Toolan2022; Toolan et al., Reference Toolan, Walpole, Shah, Kenny, Jónsson, Crabb and Greaves2023).

The advocacy function of health systems spans leading by example through healthcare professionals' individual behaviors, signing treaties promoting the cessation of fossil fuels use and the spread of plant-based diets, the endorsement of institutional and national commitments to achieve net zero emissions in healthcare, including the implementation of procurement policies, of a 100% renewables energy strategy within nations, of ambitious nationally determined contributions complying with the Paris Agreement, of enhanced climate finance (Howard et al., Reference Howard, MacNeill, Hughes, Alqodmani, Charlesworth, de Almeida, Harris, Jochum, Maibach, Maki, McGain, Miller, Nirmala, Pencheon, Robertson, Sherman, Vipond, Yin and Montgomery2023).

The implementation of circular economy (CE) strategies could provide a significant boost toward achieving all four of the described aims (advancing planetary health, enhancing the patient experience of care, reducing costs in the long-term and improving care team well-being), thus playing a central role in improving the quality of healthcare. CE can be described as an economic system that supplants the traditional ‘end-of-life’ concept (‘take-make-waste’) by emphasizing the reduction, reuse, recycling, and recovery of materials throughout the production, distribution, and consumption processes (Kirchherr et al., Reference Kirchherr, Reike and Hekkert2017). The traditional linear model has been shown to be inherently unsustainable because large-scale production and consumption play a significant role in global environmental degradation, producing excess solid waste, greenhouse gases, and other harmful emissions (MacNeill et al., Reference MacNeill, Hopf, Khanuja, Alizamir, Bilec, Eckelman, Hernandez, McGain, Simonsen, Thiel, Young, Lagasse and Sherman2020). These effects threaten public health through air pollution, water and soil contamination, ozone layer depletion, biodiversity loss, and devastating climate change. The CE transformative concept, which strives to eliminate waste through the continual use of resources, is reshaping industries and business models across the board (Sohal & Vass, Reference Sohal and Vass2022), with the healthcare sector being no exception (Kane et al., Reference Kane, Bakker and Balkenende2017). In healthcare, CE is interpreted as an inclusive economic system that adopts the principles of designing out waste and pollution (Lansink, Reference Lansink2018; Stewart & Niero, Reference Stewart and Niero2018), keeping products and materials in use, and regenerating natural systems. These principles permeate all facets of healthcare, from the design and manufacture of medical devices and equipment to the operation of healthcare facilities and the management of health-related waste. A comprehensive and collaborative approach is key in successfully implementing circularity in healthcare. These include end-of-life management (Lansink, Reference Lansink2018), business model innovation (Han et al., Reference Han, Heshmati and Rashidghalam2020), circular product design (MacNeill et al., Reference MacNeill, Hopf, Khanuja, Alizamir, Bilec, Eckelman, Hernandez, McGain, Simonsen, Thiel, Young, Lagasse and Sherman2020), localization of food chains (Health Care Without Harm, 2016), sustainable supply chain practices (United Nations Development Programme, 2020), resource recovery (Stewart & Niero, Reference Stewart and Niero2018), education (Soares et al., Reference Soares, Buttigieg, Couto, Bak, McFadden, Hughes, McClure, Rodrigues and Bravo2023), and collaboration.