Rev. Latino-am. Enfermagem How to Cite This Article Lean Thinking in Health and Nursing: an Integrative Literature Review 1

ABSTRACT Objectives: to demonstrate the scientific knowledge developed on lean thinking in health, highlighting the impact and contributions in health care and nursing. Method: an integrative literature review in the PubMed, CINAHL, Scopus, Web of Science, Emerald, LILACS and SciELO electronic library databases, from 2006 to 2014, with syntax keywords for each data base, in which 47 articles were selected for analysis. Results: the categories were developed from the quality triad proposed by Donabedian: structure, process and outcome. Lean thinking is on the rise in health surveys, particularly internationally, especially in the USA and UK, improving the structure, process and outcome of care and management actions. However, it is an emerging theme in nursing. Conclusion: this study showed that the use of lean thinking in the context of health has a transforming effect on care and organizational aspects, promoting advantages in terms of quality, safety and efficiency of health care and nursing focused on the patient.


Introduction
The term, lean thinking (lean, lean thinking mentality, or lean thinking, in Portuguese) originated from the Toyota Production System. This term was first used by Krafcik and popularized by Womack and Jones, in 1992 with the publication of the book "the machine that changed the world" (1)(2) .
Despite the origin of lean thinking in the industrial context, its principles have been used in various scenarios, including health. This universal applicability of the lean concept is due to the similarity of the production processes of organizations, regardless of their specific nature, which try to plan and execute a series of actions in a certain sequence and time, to provide value for a customer (3)(4) .
The introduction of lean thinking in health, or, lean healthcare, occurred in a structured and systematic way in 2006. That year, the Lean Enterprise Academy (LEA), a British non-profit, organization dedicated to the study and dissemination of lean thinking, organized the first congress on the implementation of lean principles in health services (5) .
Since then, health organizations have adopted lean thinking as a strategy to provide best care in several countries, including the United States- Kingdom -the Bolton Hospitals; and Australia-the Flinders Medical Centre (1,(6)(7)(8)(9)(10) .
Lean within the health environment is still little explored in Brazil. During the search on Google Scholar, in 2014, five Brazilian studies were found: one article and four dissertations. The studies explore aspects of applicability and benefits of lean in a hospital laundry (11) , the logistics activities of solid organ transplants (12) , surgical center waste material (13) , and the improvement of quality patient care and efficiency in health services (5) . Only one publication reviewed identified areas, tools, methods and best practices in the implementation of lean concepts in hospital environments (14) . Thus, lean health studies are incipient in Brazil, especially considering the magnitude of this issue in the international literature.
Lean thinking consists of a systematic approach that enables the identification and elimination of waste in production processes, focusing mainly on aggregate quality and delivering to the customer only what he considers to be of value (15) . In other words, lean is the maximization of value for the client by means of an efficient process without waste. In health, this means PubMed (Lean AND ("healthcare" OR "health care")) AND ("organization" OR "administration" OR "organization and administration" OR "organizations" OR "management" OR "health management") CINAHL (lean AND ("healthcare" OR "health care")) AND ("organization" OR "administration" OR "organization and administration" OR "organizations" OR "management" OR "health management") Scopus (lean AND ("healthcare" OR "health care")) AND ("organization" OR "administration" OR "organization and administration" OR "organizations" OR "management" OR "health management") Web of Science (lean AND ("healthcare" OR "health care")) AND ("organization" OR "administration" OR "organization and administration" OR "organizations" OR "management" OR "health management") Emerald (Lean AND (healthcare OR health OR "health care") in All fields and (nurse or nursing in All fields) SciELO lean AND (administra$ OR gestão OR organiza$ OR management OR "health management")  Data categorization was guided by the triad of a conceptual model for quality assessment in health, developed by Donabedian (19) . Aspects related to the physical structure of care environments, regulatory,  Another aspect analyzed was the profession of the authors. In this regard, of the 47 articles, 28 did not specify the professional background of the authors. Of the 19 who provided this information, it is emphasized that ten articles had nurse participation, four with the exclusive authorship coming from this profession. Figure 3 shows the characteristics of the selected studies based on the year, country, title, publication journal, study setting, and type of study.
Year/Country Title Journal Study Site Type of study

United Kingdom
Health service improvement through diagnostic waiting list management (26) Leadership in Health Services Hospital Qualitative

Netherlands
Improving the efficiency of a chemotherapy day unit: Applying a business approach to oncology (27) European  various units, including: chemotherapy (27) , cardiology (60) , hospital pharmacy (36) , emergency (42,53,69) , intensive care (65) , and surgical centers (43,45) . It is noted that by modifying the layout of these environments using the Most studies were implemented in the United States, which may be associated with the pioneering of this country in the implementation of lean concepts in health (6.73) .
With regard to the scenarios used for conducting these studies, the hospital environment predominated, across various units. This demonstrates the applicability of lean at a multiplicity of hospital care facilities. A similar result is described in a previous literature review on the implementation of lean thinking in healthcare (9) .
The incipient participation of nurses as authors on this subject was observed. This result may be associated with the origin of lean thinking in the area of administration and engineering (3) .
Regarding the content of the articles, the results will be discussed according to the categories of quality assessment from the triad in health.

Structure
Regarding the physical structure of the places where care is provided, the studies were implemented in Magalhães ALP, Erdmann AL, Silva EL, Santos JLG.
in orthopedic surgery can improve productivity due to reduced variation in practice, affecting the efficiency of the surgical procedure time and patients waiting for this procedure, control of infection, and reduction in costs due to more efficient use of surgical rooms..
It is highlighted that the use of lean thinking provides economic improvements and positive impacts on the financial income of healthcare organizations, by increasing the capacity for patient care (27,44,52,67) or allowing the reduction of financial costs due to the removal of fixed capital in the warehouses of health institutions (36.56) .
Another attribute of the structure component is human resources. By using lean to optimize the operating room capacity at a hospital in Luxembourg, it was possible to increase the number of annual surgeries without any increase in the quantity of personnel.
However, this required training and motivation of the hospital staff, which had repercussions on eliminating unnecessary waiting periods and stress before surgery and increased the transfer rate of patients in the operating room to other units (47) .

The lean methodology is anchored in appreciation
and respect for people, professional training and instructions on the workplace, enabling the improvement of professionals involved in the care process and optimizing the quality of care and patient safety (8)(9) .
Research performed in the United States revealed that the ideal professional to conduct a lean transformation in a hospital is the nurse because he has experience leading multidisciplinary teams and is committed to patient care, and can view hospital systems from the patient's perspective (49) . However, the authors indicated that nursing education needs to be rethought and the curriculum should include concepts, tools, and skills necessary to adapt lean to the patient care environment. Organizational development, lean principles, quality improvement, inventory management, consulting process, value chain management, analysis queues, diffusion of innovation, complexity science and negotiation are some disciplines that must be aggregated into nursing curricula to prepare new nurses for the lean work in health institutions. Furthermore, in a study performed in Australia, it was identified that the principles of lean methodology have provided nurses greater satisfaction and control over their work (74) .
Information systems, also recognized as a component of structure, bring together a set of data, information, and knowledge to support the planning, development and decision-making processes of health professionals involved in patient care for the health system patients (75) .
A study performed in diagnostic support services in a clinical hospital in the United Kingdom (UK) (26) used lean principles to manage the waiting list of patients awaiting diagnostic tests. The benefits identified by the study were the reduction in the waiting time for a diagnosis from 26 to 13 weeks, allowing for an early start of treatment. In addition, the study enabled increased control and better access to patient information, knowing who needed priority attention or who could remain on the waiting list for longer. Allied to this, managers were able to effectively manage the ability to meet demand because they came to understand the "profile" of waiting patients.
Thus, there was an improvement in performance and quality of service offered to patients.
Another study performed in an emergency room in Sweden (32) used a computer system for decision support, combined with lean as a tool to assist in making the best decisions. Through simulation, this program was considered and the potential effects of changes were evaluated by mimicking the behavior of a health system.
The study showed that there was an imbalance in the number of clinicians and surgeons and the supply and demand of patients received in the emergency room, which caused excessive waiting time for the patients.
In addition to allowing the comparison between the current and future state in a particular care environment, the combination of simulation with lean thinking can make the flow of care more efficient, reducing the waiting list of patients and assisting in the selection of optimal resources, the process for service management in hospitals, eliminating or minimizing the use of a trial and error approach (76) .

Process
For the care process to succeed there must be commitment, involvement and continued support of leaders for the "front line" professionals in the health institutions (26,28,(60)(61)64,68,70) and a consideration of relevant ideas proposed by these workers (29) . In a study performed in the emergency unit, managers allowed the "front line" professionals to identify problems in patient flow in that sector and to reach their own solutions (29) .  (42) .

Outcomes
All the articles analyzed reported successes and benefits for outcomes when using lean principles in health, both in health care and organizational aspects.
length; increasing the quality of service provided; increased patient satisfaction; increasing patient safety and health professionals; and employee satisfaction.
It emphasizes the need for further studies on the applicability of Lean thinking in care environments in Brazil due to most publications focus on an international level, mainly in the United States and the United Kingdom. It is also important to highlight the importance of new nursing research that specifically objectifies the participation of the profession in this context.
The participation of nurses in the scientific literature related to this issue is still incipient, even though he has been considered a professional able to lead a Lean transformation.