Engineers who make a difference: Closing the waiting gap

University of Toronto researcher’s computer model improves scheduling for hip and knee procedures

By David Brandt 

Twelve years ago, Sherry Weaver’s father had to be hospitalized after he began to experience some challenges with his health. During the hospital stay, Weaver was trying to keep track of the progress for her father’s medical care. But there wasn’t a single source that could describe a specific pathway for her father’s treatment.

“I was the person who was with them at the hospital most of the time advocating, and the one thing I found is you have a variety of different specialists working with you, especially seniors,” Weaver said. “You have an oncologist, hematologist … you’ve got everybody, but there’s really nobody quarterbacking the team. I found it frustrating to try and get clear answers about the overall direction of what his treatment was going to be, because – really – there wasn’t one person who knew that. It’s done over the phone with consults.”

There were many opinions and diagnoses involved. Weaver said it was difficult to know when the next steps would need to be taken for her father’s care, specifically when it came to any necessary surgeries. Believing such service was unacceptable, Weaver, who today is a doctoral student in industrial engineering and researcher at the University of Toronto, turned the focus of her industrial engineering skill set and research toward healthcare improvement.

Weaver already has earned a bachelor’s degree and other training in industrial engineering as well as a master’s degree in post-secondary education and an MBA. She is approaching the end of her doctoral studies while working for the Center for Research and Healthcare Engineering.

One of the major healthcare improvements Weaver said her research has provided is the development of a computer mapping program that can create a model that gives more certainty about the date a hip or knee surgery can be performed within the Canadian public health system, which is operated province by province.

Having a better idea about the window of time in which the appointment can be made, she said, gives the patient an opportunity to plan ahead for recovery with family and/or caregivers.

“We’ve got fairly long wait lists for hip and knee surgery [in Canada],” she said. “Depending on where you are and what your urgency is, you could be waiting anywhere between three and nine months. It just depends.”

Weaver said her model incorporates several factors applied to determining a patient’s surgery window. A single patient’s candidacy for surgery is determined by the number of surgical spots that exist for more urgent patients to come through, so that a time window still can be set up for the more elective patients without bumping anyone’s scheduled surgery.

“Right now, the reason they don’t give patients dates is that they’re not planning ahead with the urgent and semi-urgent patients that have to come in before them,” Weaver said. “What they’re doing is just bumping the electives down so that the urgent patients can be seen right away. So it’s primarily probability distribution, statistical analysis and a queuing model that I use to do the first cut estimate of how much time to set aside for the urgent patients.“And that’s a simple tool that the surgeons will be starting to use fairly soon in the (health system) that I’m working with.”

Weaver said a robust simulation also must be built that will incorporate operating room times, patient lengths of stay in hospitals, and the actual care pathway the hip-and-knee patients follow. Based on that, the simulation casts out several different scheduling heuristics, which she said are still being tested.

“We’re still playing around with them to figure which ones are the best, but I have a feeling location-specific will be it,” she said. “Based on which one works the best, we can then use that to create the actual scheduling system.”

The primary goal of the model, Weaver said, is not to reduce the wait times but to “make the wait times more manageable … so it doesn’t seem like the same sort of wait as it used to.” Another goal is to try out different care pathways to develop best practices that can help determine human resource requirements or time requirements. Weaver said that given a certain population – rural or urban – or a certain mix of hips, knees and osteoarthritis within the community, there might be some models that work better than others.

She added that the overall satisfaction of patients who are candidates for surgery in Canada or the U.S. is influenced by the same factors. More team care, especially in orthopedics, has been implemented in the past few years, Weaver said.

“Our care pathway that we use here in Alberta involves a case manager, so you do have your surgeon, your [occupational therapist] and your physiotherapist, but you also have [a registered nurse] that’s your case manager. So anytime you have a question, whether you’re at home waiting or after surgery, that’s your point person, your quarterback. I’m starting to see that more and more, where we’re really acknowledging the fact that the patient needs a single point of entry for information or anything they require.”

The behaviors and attitudes of the healthcare professionals who treated her father (and later her mother) weren’t as much of a concern to Weaver as the surgical appointment process itself – “They’re all working their butts off.” But after seeing the process firsthand, Weaver offered her services in computer and mathematical modeling for healthcare groups that were working on streamlining surgical and operating room processes to improve overall patient satisfaction.

“I’m on a couple of different team grants that are very interdisciplinary, where I might be one of two engineers on the entire team – most of them are clinicians and health policy specialists,” she said. “They come from a wide range. It’s really interesting to see some of the research that’s coming out of these teams, of which mine is a part of that.”

Weaver said the long-term benefits of her mapping model include, among other results, a method for a patient to set a surgical appointment that is fairly similar to what a visitor to the “most magical place on Earth” can find.

“The analogy I use is that when you go to Disneyland, you get your fast pass for the ride. So you’ve got your [surgery scheduling] window, and you just show up for that window, and you’ll get your surgery within that window.”

David Brandt is the Web managing editor for the Institute of Industrial Engineers.