2.1. Background of the Problem
Environmental sustainability in health care organisations is increasingly being recognised and explored [
9]. In fact, as described in Lenzen et al. [
5], there is a growing need to understand the health impact and the environmental footprint of health care. This is because, as the amount of health care activity provided increases around the world, there is ever more potential for damaging health through pollution and climate change. Climate change due to increased greenhouse gas emissions causes a rise in diseases such as dengue fever [
10], and in events that cause injury, such as heat waves, cyclones, floods, and droughts. These in turn lead to increases in demand for health care, costs, and greenhouse gas emissions [
5]. Health care organisations may also set standards for other entities in their commitment to environmental protection and make a significant contribution to economic sustainability in health care [
11].
Health care organisations are unique in that they produce all existing types of waste, from non-hazardous or general health care waste to potentially infectious waste, which may be carcinogenic, mutagenic, teratogenic, or radioactive. However, although only 15% of health care waste is considered to be hazardous [
12], the improper sorting of waste mixes the two types, leading to a much larger quantity of dangerous waste [
13]. This increases the risk of infections, toxic effects, and injuries to care and non-care staff, waste handlers, patients and visitors, and the wider community. To this should be added the risk of environmental pollution from the dangerous combustion gases produced by incineration of this waste or its build-up in rubbish tips, and the difficulty of designing strategies for recovery and recycling of non-hazardous waste [
14]. Furthermore, waste management should satisfy the principles of the circular economy, producing items that are highly reusable, and recycling materials that do not contain dangerous compounds, or from which they can be removed. However, infectious material contains blood or other bodily substances which do not currently have circular-specified techniques to create value, or they require excessive energy consumption. Traditional linear solutions, using the sequence extract-produce-consume-dispose, cannot, therefore, be completely discarded [
15].
A successful environmental sustainability programme has a number of advantages for the organisation:
Performance of the organisation is improved in terms of efficiency and effectiveness. These improvements are linked to improved outcomes in clinical results, the experience of staff and patients, system reliability, and company culture.
Risk is reduced, given the regulatory control of energy consumption and waste disposal.
Costs are reduced, due to lower resource consumption and waste production.
All this also leads to improvements in the positive perception of the organisation by society, due to the conservation of scarce natural resources and the promotion of the health of patients and staff [
16].
This problem can be seen at a global level, as although in middle and low-income countries, health care waste generation is usually lower than in high-income countries [
17], it is also true that, in the former, hazardous clinical waste is not generally sorted from non-hazardous waste, and the quantity of hazardous waste is in fact much greater. There is also a growing trend of increased access to health care services [
3], and in some cases no rigorous estimate of medical waste generation based on scientific studies is carried out [
18]. In developed countries on the other hand, ageing populations lead to greater hospital use. This all leads to an overall increase in production of clinical waste. Furthermore, comparison between countries is practically impossible due to differences in legislation, services, waste management systems, etc. [
3]. Although Patwary et al. [
18] suggest that it would be more reliable to compare the most economically developed countries, in practice, such a comparison is even seen to be difficult between hospitals in the same country. This is because, for example, each hospital sets its own procedures for data collection, the variables to be controlled, environmental performance reports, etc., and so it is almost impossible to apply benchmarking.
In Spain, specifically, up to a decade ago, state-run hospitals put no effort into sustainable initiatives. However, although there is now a positive trend in this regard, there is also a clear lack of guidelines and homogeneity in sustainability planning, as well as there being no assessment stage as to the outcomes of the sustainability initiatives put into practice. Public hospitals, moreover, are not willing to compare their sustainability initiatives with those of other hospitals. This means that there is no opportunity to use benchmarking [
4]. This is also true in other countries [
19].
It is thus essential to have objective tools to monitor environmental sustainability in health care organisations in order to make informed decisions about health care practices, and strategical activities or processes [
20] and costs, but primarily to prevent or at least minimise negative environmental impact, in turn reducing the impact they may have on health [
5]. Sustainability assessment is increasingly recognised as an effective analytic methodology and management tool for improving sustainability performance [
6], within a process of continuous improvement.
There are still important gaps in the literature regarding sustainability in hospitals, although we are starting to see assessments of environmental impact and the use of natural resources, both in individual hospitals and over an entire health system [
21]. However, there is no case in the literature of an environmental assessment system for health care organisations which takes into account the various stakeholders. The interests of stakeholders coincide in many areas, but in others there are in conflict, and so taking into account the opinions of various stakeholders, such as patients and experts, provides a fuller vision of the level of environmental sustainability valued by the community.
2.2. MCDA Methods in Environmental Sustainability
Contributions on sustainability performance in private and public health care organisations are very scarce [
4], despite the importance of sustainability in this sector.
The problems in quantifying sustainability stem from using only qualitative aspects, and because different stakeholders, such as policy makers, social scientists, economists, engineers, patients, etc., tend to identify different sustainability criteria or indicators depending on the particular class of application [
22].
Multicriteria decision analysis (MCDA) techniques help decision makers simplify a complex problem by breaking it down into three elements [
23]:
Alternatives to be assessed (options, strategies or action plans).
Objectives or aims and criteria by which the alternatives will be assessed.
Criteria weights which bring together the judgements, knowledge, information, etc., of the decision makers.
A MCDA model can include both quantitative and qualitative information, as well as different stakeholders, scenarios, goals and a variety of aspects to be assessed. The complexity inherent in the decision-making process is further complicated by the often incomplete or vague nature of the information available [
24]. MCDA addresses this problem by including uncertainty methodologies such as sensitivity analysis, validation, probability models, fuzzy set theory and grey systems theory [
25]. In any case, it is an indispensable condition that the decision-making process be simple and compressible to decision makers. It is these characteristics that make MCDA techniques very useful in environmental assessment [
26,
27], since multiple technical, social, political, economic, and environmental matters are usually involved, which may frequently conflict [
28,
29]. It can also be useful to include a number of decision makers with different responsibilities in the Health Care System. Although there are many MCDA techniques, and no technique is universally preferable to the rest, there do exist techniques that are more appropriate to a given problem and the features it involves [
30].
MCDA techniques allow objective models to be designed, as they are built with mathematical techniques, and so they can help to ensure public acceptance of the results [
31]. This question is very important to a health care organisation since in most cases, in Spain at least, they are publicly owned. This means that the use of these techniques increases the consistency, transparency, and legitimacy of decisions [
32].
There is an extensive literature, which successfully uses different MCDA methods to assess environmental sustainability and/or environmental impact [
7,
31,
33]. Sustainability assessments based on MCDA are generally seen to cover the three dimensions of sustainable development, economic, social, and environmental, although they mainly focus on environmental impacts [
34]. However, environmental aspects are not always analysed from the life cycle perspective. Also, the models designed do not provide a wholly quantitative assessment of the economic and social questions [
35]. It was found that nearly all the MCDA methods available have been used, although the analytic hierarchy process (AHP) is the leading technique.
Among the contributions that use one or more multicriteria techniques in a crisp environment are the following. Stefanović et al. [
36] compared the results obtained with AHP and the analysis and synthesis of parameters under information deficiency (ASPID) method to assess sustainability of waste management scenarios. The best sustainable waste management scenario is found to be similar with both methods, and is related to composting of organic waste and recycling of inorganic waste. Büyüközkan and Karabulut [
37] integrated AHP, for determining the weights of the evaluation criteria, and VIKOR for ranking energy project alternatives, to assess and rank the sustainability performance of one thermal power and three renewable energy projects. Loikkanen et al. [
38] applied stochastic multicriteria acceptability analysis (SMAA) to the assessment of sustainable energy solutions such as different configurations of solar power, ground source heat, and roof constructions, along with district heating for a building. Talukder and Hipel [
39] used the Preference Ranking Organization Method for Enrichment Evaluation (PROMETHEE) method to assess sustainability, using the productivity, stability, efficiency, durability, compatibility, and equity of agricultural systems in coastal Bangladesh. Melkonyan et al. [
40] analysed sustainability in last-mile logistics and distribution strategies, also estimating the impact of dynamic changes on the design, using the PROMETHEE. Ziemba [
41] looked at strong sustainability from the perspective of a limited capacity to replace certain natural capital with other kinds of capital. This was done using PROMETHEE for sustainability assessment (PROSA), a method that is more flexible in its choice of criteria and groups, and that offers the decision maker more analytical possibilities, allowing the expected strength of the sustainability to be defined. Deshpande et al. [
35] assessed the environmental, social and economic impacts of landfilling, incinerating, and recycling of waste fishing gear through two scenarios, i.e., recycling inland and exporting, using multi-attribute value theory (MAVT). Khan [
42] used a simple multi-attribute rating technique (SMART) to assess sustainability in the power generation sector in Bangladesh in a model built with 19 sustainability indicators, of which 10 concern social factors, four environmental, and five economic. The result was to show that the sustainability of the power generation sector will deteriorate in the future.
Research on environmental sustainability in the fuzzy environment is very scarce, but the following studies should be noted. Hu et al. [
43] created a framework based on the Global Reporting Initiative Guidelines, a kind of scorecard for assessing the quality and the content of sustainability reports from 16 companies operating in Taiwan. A fuzzy Delphi method with expert questionnaires was used to choose 44 indicators structured into 18 criteria. Subsequently, the fuzzy AHP was used to calculate the weights of the criteria and give a score to each sustainability report. Ezbakhe and Pérez-Foguet [
7] used a modified elimination and choice translating reality (ELECTRE) III model to incorporate the uncertainty in the decision process, and so determine discrimination thresholds for planning renewable energy in Turkey. The model was compared with other research which used three different MCDA techniques with the same goal, namely fuzzy set theory combined with AHP, used by Kahraman and Kaya [
44], fuzzy AHP and fuzzy technique for order preference by similarity to ideal solution (TOPSIS) by Erdogan and Kaya [
45], and modified ELECTRE in a hesitant fuzzy sets environment by Mousavi et al. [
46]. In all these studies, considering a veto-to-preference ratio of eight in Ezbakhe and Pérez-Foguet [
7], the findings are that wind energy is in first place, followed by solar, geothermal, biomass, and hydropower.
A further review of the literature on environmental questions analysed via MCDA techniques can be seen in Huang et al. [
31], Büyüközkan and Karabulut [
34], Kiker et al. [
47], Herva and Roca [
48], and Neste and Karjalainen [
49].
An increasing number of contributions combine geographic information systems (GIS) and MCDA techniques, as they can potentially support the solution of a wide variety of environmental decision and assessment problems, according to multiple criteria and decision makers’ preferences. Among them is Boggia et al. [
50] which described a model for sustainability assessment integrating TOPSIS with GIS to obtain a traceable and transparent system using a set of indicators structured in the economic, social and environmental sectors, to attempt balance between the three dimensions of sustainability. Jelokhani-Niaraki et al. [
51] focused on the semantic interoperability of GIS and MCDA, using an ontological framework to assist in environmental assessment and decision making.
However, in the area of health care organisations, environmental assessment is only beginning to be carried out, both for individual hospitals and for the health system in general [
21]. The literature includes some contributions analysing the assessment of environmental issues in health care organisations, for example, with respect to guidelines, ESC [
52] provided practical advice to help health care facilities improve their environmental management systems and performance. CMPBS [
53] provided a guide for a self-certifying metric toolkit of best practice that designers, owners, and operators can use to assess their evolution towards high-performance environments. The World Health Organization identified the elements of a climate-friendly hospital [
54]: energy efficiency, green building design, alternative energy generation, transportation, food, waste and water. Smith [
55] analysed the concept of sustainable health care. Intraruangsri [
56] broke down the idea of a green hospital to analyse the evolution of the concept, and the guidelines for applying it successfully.
McGain and Naylor [
21] identified the following essential areas of environmental sustainability in hospitals: hospital design, direct energy consumption, water, procurement, waste, travel and psychology and behaviour. Pinzone et al. [
57] analysed the role of green human resource management practices on the environment. Castro et al. [
58] set out a method for assessing the sustainability of health care buildings by means of a list of indicators and considering the perspectives of the main health care stakeholders. Ref. [
59] continued with that aim, but introduces the concept of sustainable-effective design, adapted to the Portuguese building sector. Kleber [
60] described the potential role of nurses in waste reduction in hospitals, by unifying and involving staff in shared governance models. Carino et al. [
9] identified the environmental and associated economic impacts of hospital food services and the results from different strategies that can improve the environmental sustainability of food services. Factors to bear in mind include the importance of commitment and communication between the hospital and local stakeholders in achieving environmentally sustainable food services, and also control processes to minimise the production of food waste, and bring about the long-term sustainable sourcing of some of the ingredients. Nutritionists should also analyse the environmental sustainability of the food services in hospitals.
In a more quantitative and practical way, Nascimento et al. [
16] assessed the level of sustainable practices with an environmental dimension in Brazilian hospitals. Areas such as operational performance, where ISO 14,001 certification, the publication of sustainability reports, and the existence of an area dedicated to corporate sustainability are looked at, together with the maturity of hospitals in relation to sustainability practices. 58% of the hospitals surveyed returned the rating very high or high, but additional sustainable actions are recommended, such as establishing dialogue with stakeholders. Also looking at Brazilian hospitals, Blass et al. [
19] developed a practical framework to measure environmental performance. The framework includes three phases, eight steps and fourteen worksheets, and has been applied to six hospitals, helping them to comply with current legislation and quality standards. Tomson [
11] describes a set of actions to minimise greenhouse gas emission in hospitals, with the categories reduction in pharmaceutical use, more efficient use of buildings, waste reduction, reduction of energy use, sustainable procurement, health care activity for hospital staff and the community (reducing obesity and smoking), separation of emergency and elective care, telemedicine, improvements in monitoring of chronic illnesses by patients (activated patients), improvements in end-of-life care and reform of the payment system. The study of Thiel et al. [
61] was along similar lines, but it focused on laparoscopic surgery, and showed that the greatest savings in carbon footprint were in the choice of specific anaesthetic gases, and minimising the materials used in surgery (reusing cotton towels, switching to reusable gowns and drapes, etc.). In addition, optimising energy use, specifically heating, ventilation, and air-conditioning systems can contribute to a reduction of 10% in the carbon footprint, and recycling surgical waste, 5%. Lenzen et al. [
5] assessed the contribution of health care organisations to environmental damage, and found an environmental impact of between 1% and 5%, depending on the indicator used, and over 5% in some countries. For example, in emissions of greenhouse gases and air pollutants, health care organisations have a high footprint: 4.4% of greenhouse gases, 2.8% of particulate matter, 3.4% of NO
x, and 3.6% of SO
2. These are mainly caused by transporting patients and heating buildings and water.
There is research that includes MCDA techniques in these assessments in the health care organizations, although it is very limited. It includes the following contributions in the crisp environment. Romero and Carnero [
62] built a model with the AHP, with the aim of facilitating recognition of Standard ISO 14,001 or Regulation EMAS. The model uses a total of 54 indicators classified into three categories: environmental behaviour, environmental management and environmental condition. This classification follows the recommendations of the Commission of the European Communities for the application of Regulation (CE) nº 761/2001 [
63]. Five alternatives are used to classify a hospital, according to the level of satisfaction of the indicators: excellent, very good, good, deficient and very deficient, as well as the alternatives maximum and minimum which characterise a hospital with the highest and lowest level respectively in all the indicators. Zamparas et al. [
64] built an AHP model to assess procedures, techniques and methods of handling infectious waste in the health care unit of a general hospital in Greece. Staff/patient environmental sensitivity was included in the criteria, patient judgements were not considered, as three experts in health care organisations were used. The resulting values are very good in environmental management, due to good behaviour in environmental policy standards and waste management procedures. However, staff sensitisation programmes, and other actions on green procurement, should be developed.
In the fuzzy environment, the following stand out: [
65] built a model using fuzzy AHP with utility functions to evaluate the quantitative criteria. This model was applied to a public (state-run) hospital, and gave a valuation of 0.764 out of 1, showing that this type of model can play a positive role in the process for certification to Standard ISO 14001. However, as the hospital performs a different number of care services each year, comparing results between years, or between organisations, is complex. Carnero [
8] described a model combining fuzzy AHP and utility theory to evaluate environmental sustainability in health care organisations. The model assesses the quantitative criteria, looking at the number of services provided annually by the organisation, meaning that the results are comparable over time, and between different health care organisations. The model has been applied to a hospital and to a walk-in centre which only treats out-patients, and it shows when given actions carried out in a given year have made a greater contribution to environmental sustainability.
It should be underlined that the inclusion of a variety of stakeholders in decision models, as a success factor in performance assessment models, is increasingly common [
66]. However, this is not true of environmental performance in health care organisations. Nonetheless, there is a need to include in the model the people directly involved in the production and handling of health care waste, such as care and non-care staff of the health care organisation or policy makers. In addition, environmental bodies, environmental health practitioners, voluntary groups, advisers, researchers and students should also be considered [
67], and the general population, due to broader environmental awareness, and the need to reduce public spending and the introduction of stronger environmental regulations. Also, the public is aware of real problems in this area, as they suffer environmental problems daily [
30]. Thus, ensuring that the results obtained are easily intelligible to non-experts, and that the assessment is traceable and transparent [
50], is key in the production of assessment models.