DescriptionHealthcare delivery presents many opportunities for real-time data to support rapid decision making, but the COVID-19 pandemic placed unparalleled pressure on health systems in the United States to make decisions with limited information. Safe, efficient, and high quality COVID-19 vaccination delivery presented our health system a unique challenge that we addressed with an interdisciplinary approach to design our mass vaccination clinic.
Simulation Modeling in Healthcare
Simulation modeling has been used for decades in healthcare to evaluate the efficiency of existing workflows and to innovate novel approaches to care delivery[1,2,3,4,5]. Despite a significant base of literature extolling the benefit of simulation modeling in healthcare, its practical application is not routine practice, particularly in non-academic healthcare systems. In fact, few published works have documented actual implementation in the healthcare systems where simulation models were developed. Katsaliaki and Mustafee reported that only 11 out of 201 and Mohiuddin et al. found only three of 21 studies were implemented in the real-world. This was not the case for this project where we leveraged process improvement, simulation, and computer modeling to rapidly launch a COVID-19 vaccination clinic.
Vaccine Clinic Project
The COVID-19 pandemic has brought about one of the most pressing mass vaccination initiatives confronted in modern history. To decrease the effect of the virus on hospitalizations, lasting physical sequela, loss of jobs and mortality, a massive segment of the population must be vaccinated in a limited amount of time. Mass vaccination efforts have been used for over 200 years to rapidly increase population immunity, but there remain many challenges to quick and effective delivery of vaccines . As a primary mass vaccination site, we had to overcome these challenges and established three goals 1) maximize vaccine distribution with zero waste, 2) provide every clinic patient an excellent experience, and 3) maintain an excellent work environment for every clinic volunteer.
The development of the vaccine clinic was predicated on the delivery of 1000 shots in an 8-hour day. To achieve this target, along with the goal of providing an excellent patient experience with no lines or bottlenecks, one patient had to come in and one patient had to leave the clinic every 28.8 seconds.
Prior to the simulation, meetings with vaccine clinic leadership were held to validate project scope. Three tools were used to guide the conversation. The project form outlines the current situation, questions to be answered, and scope. It was used to determine the front-line coworkers who would simulate and develop the new standard process. The value stream map is a visual representation of the process, which was built using existing flu vaccine clinic standard work documents, door screening procedures for COVID-19, hospital registration requirements, and COVID-19 vaccination guidelines from the Indiana State Department of Health. The percent load chart shows the time each role takes to complete a cycle of work in the process.
The artifacts from these tools provided the foundation for the simulation – framing the problem, illuminating process gaps, and delineating information and supply requirements for each step. The simulation days were “staged rehearsals” with over 20 volunteers acting as mock patients and were utilized to collect task and walk times between service touchpoints for a variety of scenarios. At the end of three days of simulation, stakeholders were provided standard work for nine roles, process times for each area, and a functional physical clinic setup (Figure 1).
The standard of work documents and on-site rehearsal sessions were utilized to collect key data feeding into a custom web-based simulation software that was built using Dart. The COVID-19 vaccination clinic simulation tool (simulator) allows vaccination clinic managers to predict flows of patients going through the clinic on a given day based on various inputs (Figure 2), such as task times, walking times, supplies, and staffing numbers. The simulator models the action and movements of each individual patient and staff member throughout the hours of operation of the clinic, with a one-second granularity. The simulator distributes patients throughout the day in 15-minute “blocks” of time; to account for real-world “messiness,” the software randomly simulates patients arriving a little earlier or slightly past their appointment time.
Once all the inputs are entered, the simulator computes and then displays an overview of staff utilization; the average patient wait times at registration, vaccination, and screening; and the average time it takes a patient from point of entry to exiting the clinic. This overview screen facilitates the quick identification of any major problem with the inputs, such as too many vaccinators leading in an underutilization of vaccinators, as seen in Figure 2. The simulator also allows the operator to view minute-by-minute visualizations of the lines forming in front of the different stations, the occupancy of the holding area, and the number of supplies left at each station before replenishing. The simulator was made public and is available at https://hsir.parkview.com/covidvaccine/.
In addition to finding light in the darkness of the pandemic, our health system also realized the power of combining Lean methods, simulation, and modeling that has been revealed in the literature[10, 11]. While simulation models of healthcare operations have been developed for decades, including mass vaccination[12,13], these models are often developed without stakeholder engagement and are rarely operationalized[3,6,7]. Trust between health system leaders and the simulation developer is an important element in successful implementation and proved to be essential. Our interdisciplinary team worked closely with over 20 departments and applied process improvement and simulation techniques to build a digital model that continues to be used operationally to adapt clinic workflow to changes in patient population, vaccine delivery, and volunteer availability. With refinements projected by the model, the clinic exceeded the original target and can deliver 1300 vaccines in an 8-hour day. Most importantly, we have brought comfort to our community as depicted in this quote “Many things in society are negative. Problems abound. However, the recent COVID-19 vaccine site for the elderly at Parkview’s Mirro Center was an example of how things can be done well.”