One Simple Approach to Improve Healthcare Quality


The US healthcare system serves a rapidly expanding elderly population undergoing increasingly complex medical care shifted to an outpatient clinic environment. The resulting prolonged waiting time limits quality, patient and employee satisfaction, and represents waste.

While waiting time is commonly accepted as one measure of patient satisfaction, health care providers have not yet commonly recognized prolonged waiting time as a defect in care that can be formally assessed through traditional manufacturing techniques such as Lean and Six Sigma. Derived from the Toyota production system, Lean emphasizes value creation steps in a process by eliminating waste such as transportation, inventory, motion, waiting, over-processing, overproduction, and excessive production.[1]

From an operations standpoint, Lean can be applied to health care because processing a patient through an office visit represents the creation of relative value units through multiple steps, involving initial check-in at the reception desk, initial intake by a nurse or patient care technician, examination by the physician, diagnostic testing and treatment, followed by check-out.

Six Sigma, developed by Motorola in 1986 and popularized by Jack Welch’s adoption at General Electric in 1995, is a statistically rigorous process improvement method organized around steps to define, measure, analyze, improve and control a problematic process (corresponding to the acronym, “DMAIC”).[1] Processes with poor reproducibility and/or high variation are often identified as defects.

During a patient visit, high variations in throughput time are common, as the flow through the office varies, depending on whether patients are new or established, and whether they require extensive testing and/or treatments. This variation contributes to clinic inefficiencies, prolonged waiting times, and also represents a defect in care. Although widely used in the manufacturing industry, there is very little literature describing the use of Six Sigma techniques to improve waiting times in outpatient clinics.

In a recent study we conducted, Lean Six Sigma process improvement was employed in such an outpatient setting to decrease patient visit time, demonstrating that this approach can yield enormous aggregate improvement in health care. In this study, process flow maps were created to determine the most common care pathways within clinic. Three months’ visits from the electronic medical record system, which tracks patient flow times at each process step in the office were collected. Care tasks and care pathways consuming the greatest time and variation were objectively identified and modified.

Follow-up analysis from 6 weeks’ visits was conducted to assess and quantitate improvement. This analysis revealed that nearly all the patients took one of five paths through the office. This facilitated redesign of patient flow to eliminate some waiting room time by having staff members immediately start patients into one of those five paths. The follow up analysis revealed a statistically significant decline in mean visit time by 18% and in visit time standard deviation by 4.6%. The patient and employee satisfaction scores improved as well.

Because most health care is delivered in an outpatient clinic setting, process improvement in this setting would potentially result in the greatest aggregate improvement in health care delivery. However, the literature on the implementation of Lean and Six Sigma in this area is also limited. One study utilizing Six Sigma tools in a gynecology clinic improved waiting times, increased number of visits per year, improved patient satisfaction scores, and enhanced clinic revenues.[2] In an internal medicine residency clinic, a study employing Lean Six Sigma techniques showed that incremental changes in workflow processes improved overall practice efficiency and even improved adherence to preventive health care.[3] Although another study in an ophthalmology clinic revealed a significant correlation between patient waiting time and overall patient satisfaction score,[4] there have been no studies of Lean Six Sigma techniques in ophthalmology clinics to improve waiting times.

The Lean Six Sigma process employed in our current study can be applied to other clinics in which waiting times are problematic. Increasingly elderly populations, insured by taxpayer-funded Medicare programs, are undergoing increasingly complex care in an increasingly outpatient environment with prolonged waiting times, not only in ophthalmology, but in many other specialties such as internal medicine and cardiology. By improving flow through the clinic, patient satisfaction and clinic capacity can be improved with minimal increase in cost. This enhances the quality of care with concurrent cost containment, the holy grail of health care.



Pyzdek, T. and P.A. Keller, The six sigma handbook. Fourth edition. ed. 2014, New York: McGraw-Hill Education. xiv, 690 pages.

Bush, S.H., et al., Patient access and clinical efficiency improvement in a resident hospital-based women's medicine center clinic. Am J Manag Care, 2007. 13(12): p. 686-90.

Fischman, D., Applying Lean Six Sigma methodologies to improve efficiency, timeliness of care, and quality of care in an internal medicine residency clinic. Qual Manag Health Care, 2010. 19(3): p. 201-10.

McMullen, M. and P.A. Netland, Wait time as a driver of overall patient satisfaction in an ophthalmology clinic. Clin Ophthalmol, 2013. 7: p. 1655-60