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StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-.
Emily Barr ; Grace D. Brannan .
Last Update: January 11, 2024 .
Quality improvement is integral to many sectors, including business, manufacturing, and healthcare. Systematic and structured approaches are used to evaluate performance to improve standards and outcomes. The Institute of Medicine defines quality in healthcare as “the degree to which health services for individuals and populations increase the likelihood of desired health outcomes and are consistent with current professional knowledge.”[1]
In healthcare, quality improvement methods are traced back to the 19 th century; 2 examples are the advocacy for handwashing in medical care by an obstetrician, Ignaz Semmelweis, and the betterment of living conditions and excessive mortality of soldiers in army hospitals to nurse Florence Nightingale.[1] Many quality improvement methods can be applied to healthcare, 3 of which include Plan-Do-Study-Act (PDSA), Lean, and Six Sigma. Each method has a unique goal-oriented outcome that has been applied to healthcare to streamline and optimize processes.
PDSA is a cyclical quality improvement method often compared to the application of the scientific method, differing from Lean philosophy due to its iterative format.[2] PDSA was adapted to healthcare in 1996 by statistician Gerald J. Langley and built upon its manufacturing origin in 1986 by statistician Edwards Deming.[2] PDSA focuses on 4 stages: plan, do, study, and act.
The first stage, plan, begins with identifying a project goal. The next stage, do, is a small-scale implementation of the plan applied to meet the goal. The scope or size is small to enable any pivots to be addressed promptly. The study stage compares predicted data outcomes to achieved data outcomes. The act stage combines data from the prior 3 stages into an improved executed plan. The 4 steps must be thought out and repeated for a refined process. PDSA is not a standalone method but utilizes other quality improvement tools and is a key component of the Model for Improvement.[[2][3][4]
Lean stems from the Toyota Production System (TPS) and focuses on improving quality and productivity through efficient and value-added processes by eliminating 3 items: waste (muda), unevenness or inconsistencies (mura), and overburden or unreasonableness (muri).[5][4][6][7] TPS, also called the “Toyota way,” is credited to Japanese engineer Taiichi Ohno. Its origin can be traced back to the Henry Ford assembly line and Toyota Motor Corporation production system in the 1950s, as they tried to increase value-added products or services—that is, entities customers were willing to pay for while decreasing extraneous products or services.[8]
Mura can be corrected by standardization to create dependability and reliability. Muri emphasizes creating a culture of problem-solving instead of blaming. Lean has identified 8 wastes or muda.[5][6] Defects refer to work that needs modification, alteration, or repair. Overproduction is ordering unnecessary tests.[6] Waiting can be in the form of waiting for supplies, a turn to use a machine, to be seen by a provider, or for test results, to name a few. Unutilized talent refers to wasted people skills. Transportation may include transporting supplies from one area to another or moving patients from the hospital room to the laboratory for tests. An example of inventory is storing or buying excessive medical supplies, especially if they expire before usage. Unnecessary motion may include wasted movement for providers, caregivers, and patients.[6] Extra-processing denotes unnecessary steps or work.
5 overarching principles contribute to Lean methodology implementation:[9][6]
Identifying the value of a product or service to the customer, which could be the patient or another department in the hospital.
Value stream mapping is a visualization method of processes, materials, the flow of information, and resources involved in creating a product or service to identify those that add value and remove those that are wasted.[5][10]]
Creating flow by eliminating barriers. Establishing pull based on actual customer demand rather than forecasted demand.Establishing perfection means that in every system, efforts to eliminate waste are continuous and should always strive to meet or exceed customer or patient needs and satisfaction.
Core to Lean is Kaizen, a focused, team-centric, continuous, and rapid improvement endeavor to implement small changes into systemic, standardized improvement cycles. The understanding of Kaizen is reflected in its etymology, derived from the “Japanese words “kai,” meaning change, and “zen,” meaning good.”[11][7]
Lean uses different tools to achieve its goals. 5S refers to sorting, setting in order, shining, standardizing, and sustaining elements required to sustain a clean, orderly, and organized workplace.[10] Just-in-Time (JIT) refers to supplies being available when needed.[12] This is feasible if there is consistency and uniformity in the system, which allows predictability and control. JIT works in tandem with Kanban or the inventory system, which relies on supplies approval and documentation. A3 is a visual and structured tool that identifies problems and solutions using an A3-sized or 11 x 17 inches paper.[13]
Like Lean thinking, Six Sigma is a methodology focused on optimizing performance, controlling, and decreasing variability.[14][4] Six Sigma techniques were developed in the ’80s by Motorola.[15] Six Sigma is derived from a statistical concept of 6 standard deviations from the mean or 3.4 defects per million units.[16] Six Sigma often focuses on quantitative healthcare analysis to refine delivery efficiency while increasing patient safety.
Six Sigma is different from other methodologies in that it is focused on financial outcomes and statistical outcomes and requires management support.[15] Leadership support is needed to set the goals for Six Sigma initiatives and train or hire specific personnel in the form of “Belts” as part of the more formalized quality management structure.[17] The “Belts” signify training and project involvement levels and usually require certification.[17] A Master Black Belt is the most experienced, trains the other belts, and is the project consultant. Black Belts leads the execution of the Six Sigma projects. Green Belts leads project implementation under the guidance of Black Belts, and Yellow Belts participates as a member in projects.[17]
Six Sigma employs 2 methods:[17][14][8][4]
DMAIC or Define, Measure, Analyze, Improve, and Control. DMAIC is used for improving current processes.
DMADV or Define, Measure, Analyze, Design, and Verify. DMADV is employed when developing new processes and products.
Different well-known quality improvement tools are used within the different phases of DMAIC or DMADV. Here are a few examples:[18][19][20][21]
Design of Experiments: An approach for projects that utilize a structured method of studying variables and outcomes. It may include randomization, established research approaches such as experimental or quasi-experimental, and statistical data analysis.
Cause and Effect Diagrams or Fishbone or Ishikawa Diagrams: A visualization of factors contributing to a given effect, such as prolonged length of stay.[22]
Control Chart: A graph that shows variation in data relative to a mean value and upper and lower limits.
Pareto Chart: Stemming from the 80/20 Pareto principle that 20% of factors cause 80% of the problems, is a bar chart showing the frequencies of factors in descending order from left to right to easily identify the most important factors.[22]
Root Cause Analysis (RCA): A multi-step process of identifying problems, reasons for the problem, and corrective actions after an adverse event occurs.
Failure Mode and Effect Analysis (FMEA): A process of identifying possible failure points in a process as a preventive way to address these weaknesses before they cause problems.
In the early 2000s, the Xerox corporation developed Lean Six Sigma or LSS.[8] LSS marries Lean and Six Sigma approaches and toolboxes and has been used in different business sectors, including healthcare.[8][17] Successful LSS implementations usually employ waste reduction first before optimization or variability reduction. The healthcare sector benefits from LSS because of reduced waste and cost, improved and optimized processes, and enhanced patient satisfaction in one continuous effort.[23][24]
Common challenges in Lean methodology include individual resistance to change, discomfort with inter-professional collaboration, and organizational process variations.[25] Methods to overcome barriers include maintaining qualified leadership, obtaining feedback, and pursuing feasible projects.[25] Adequate rollout from senior leadership can be executed by ensuring key stakeholders formally understand Lean practices.
JIT supply chain reduces extra inventory and cost. However, during COVID-19, the lack of supplies, especially personal protective equipment or PPE, exposed the healthcare goal of a slim inventory via reliance on JIT which, during the pandemic, endangered both providers and patients.[12]
PDSA relies on properly executed, small-scale tests before scaling to larger trials.[2] This belief lies in an understanding that small-scale projects are likely to harbor more controlled environments, allowing for more agile pivots upon seeing favorable changes. However, a recent systematic review indicated that fewer than 20% of articles used iterative cycles and small-scale tests, which could suggest that larger tests were not optimal.[2] Another area of concern when enacting a PDSA cycle is pursuing an overzealous, large-scale goal that may lie beyond the method's extent.[3]
A bigger issue with PDSA implementation is oversimplification, which results in projects not fully adhering to PDSA principles.[2] This opens the possibility of incorrect PDSA implementation with inadequate mobilization of resources and skills, jeopardizing scientific rigor.[2] When applying PDSA cycles to healthcare, leadership must ensure adequate resources, including clinical staff, medical technology, inventory, registries, and funding, are present to integrate PDSA cycles into the workflow.
Six Sigma aims to achieve process improvement by decreasing defects and enhancing quality. In healthcare, this often presents as reducing patient harm while increasing patient safety and patient satisfaction. One of the main challenges faced in Six Sigma operations is the cost of hiring a full-time project manager, an in-house expert, or a Six Sigma belt. Another obstacle is the institutional culture, which requires buy-in from all stakeholders for the project's success. This buy-in must last throughout the project duration, which can exceed 24 months in the case of major improvements.[26] While recognized Six Sigma belt certificates can be obtained and offer credible structure, they are not mandatory for process improvement. Formal Six Sigma programs offer training courses, which, combined with field experience, enable certificates to be sequentially obtained (white belt, yellow belt, green belt, black belt, to master black belt).[14] There are concerns that Six Sigma is not being properly used to its full potential in healthcare.[27]
Improving safety culture is critical for long-term quality improvement in healthcare despite challenges in PDSA, Lean, and Six Sigma.
Errors and hazards are present, realistic concepts in healthcare. An extrapolated estimate of over 250,000 deaths based on 2013 hospital admissions occurs in the US annually due to medical errors.[28] Such errors cause losses upwards of $20 billion annually.[28][29] Excessive wait times and process bottlenecks may lead to delayed diagnoses, treatment, and barriers to appropriate medical triaging.[30][31] Such outcomes may cause increased patient stress and detrimental effects if delayed reporting is congruent with disease progression, leading to adverse patient outcomes.[30][31]
Technology in medicine is critical to patient care, allowing centralized team communication, increased patient engagement, and digitized records. Though technological advances such as electronic health records have enabled ease of data acquisition and application of quality improvement functions such as medication allergy alert pop-ups, early rejection and abandonment of technological solutions are seen in healthcare, potentially linked to varied acceptance by users.[32]
The federal healthcare agency Centers for Medicare and Medicaid Services (CMS) has a reimbursement program in healthcare that draws attention to the clinical significance of quality improvement methods in healthcare.[33][34] The Medicare Value-Based Purchasing (VBP) program uses direct financial metrics to incentivize performance.[33] Metrics include adverse events, mortality, and cost reduction.
This agency evaluates organizations on quality measures and adjusts reimbursement based on metrics, promoting quality improvement and patient care.[34] By adopting quality improvement metrics, healthcare organizations can address patient safety and satisfaction while being mindful of long-term financial and efficiency goals.
Quality improvement is a “combined and unceasing effort of everyone – healthcare professionals, patients, and their families, researchers, payers, planners, and educators to make the change that will lead to better patient outcomes, better system performance, and better professional development.”[35]
Interdisciplinary teams used synonymously with interprofessional teams, represent multiple constituents within healthcare working in conjunction with one another. Interprofessional has historically been used more narrowly, signifying working professionals from different professions, while interdisciplinary has traditionally been used more broadly, encompassing distinct healthcare staff members.[36] Adopting interdisciplinary teamwork is critical in healthcare to foster collaboration and diversity, strengthening systemic culture and goals.
One example of quality improvement methods and interdisciplinary teamwork intervention is seen in the Swiss Cheese Model, which was first referenced in 1991 and published in 1997 by psychology professor James Reason.[37] The model compared natural eyes in Swiss cheese to eyes or holes in healthcare systems. Specifically, the holes in healthcare, synonymous with errors, led to adverse events due to an alignment of multiple holes or multiple opportunities for improvement. Each slice of cheese represents a protective barrier, including policies, technology, and teamwork.[38]
Though teamwork is needed in healthcare, it may fail without proper communication, which is a leading cause of inadvertent patient harm, including medication errors, treatment delays, and wrong-site surgeries.[39][40] Factors influencing communication failure include training differences among health fields, hierarchy, and lack of standardization.[39]
Without mutual collaboration and discussion based on unique perspectives, quality improvement metrics may be prone to fail. By having long-term end goals in mind, such as patient safety, interdisciplinary teamwork can foster quality improvement initiatives. A positive culture of safety does not focus on individual action or error but rather encompasses organizational accountability fostered by teamwork.[41]
Collaborative interaction in healthcare is seen in literature to contribute to improved medical effects.[42] Once an organization adopts the importance of interprofessional team interventions, proper interprofessional monitoring in systematic observation is implemented. A risk management team often achieves such tracking, a set of systems in place to detect, monitor, and prevent harm stemming from the 2005 Congress Patient Safety and Quality Improvement Act.[43]
One example of a risk management intervention is an RCA.[20] The National Patient Safety Foundation recommends an RCA comprising diverse team members ranging from physicians and supervisors to ancillary staff and quality improvement experts.[43][44] Appropriate monitoring can help maximize quality improvement in healthcare, allowing organizations to effectively utilize quality improvement methods such as LEAN, PDSA, and Six Sigma.
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Disclosure: Emily Barr declares no relevant financial relationships with ineligible companies.
Disclosure: Grace Brannan declares no relevant financial relationships with ineligible companies.
