Monday, October 20, 2008

Healthcare and OR in Canada: selected talks at INFORMS 2008

The Ontario Ministry of Health in Canada would like to reduce the delay in transfer of care from the ambulance to hospital emergency department. The delay usually occurs when the ambulance is at the hospital site waiting to transfer patients to the emergency wards. The ministry would like to use alternative sites, UCCs (Urgent Care Centres), to accommodate the ambulance patients who would typically be discharged on the same day, so as to free up time at the ED needed to deal with these type of patients. The good news is that the ministry has the smarts to research the feasibility of this solution before doing anything. However, the bad news is that the two databases necessary (EMS & hospital databases) for doing this study do not have identifiers for patients. What’s new, right? Healthcare and bad data almost always go hand in hand. Therefore, the team lead by Ali Vahit Esensoy at the University of Toronto cannot identify the same patient in both databases. However, using accurate GPS timestamps and various triage indicators, the team was able to come up with an algorithm to match over 90% of the patients in the two databases. Then with the help of the physicians and staff, the team was able to devise a set of decision rules to filter out the patients that would be candidates for UCC. The result of the study is that the proposed UCC solution is in fact not a good idea, because there are simply not enough such patients. This is a classic case illustrating the importance of quantitative analysis for informed decision making.

On the west coast of Canada, two groups within the CIHR (Canadian Institutes of Health Research) team in Operations Research to improve cancer care, are making impacts in the BC Cancer Agency. They would like to call out to the OR community to help them join in their efforts of establishing an online community to share resources among the OR people working in cancer care.

The British Columbia Cancer Agency (BCCA) is the sole cancer treatment provider for the entire province. The problem to be resolved at the facility is a lack of space (examination rooms and space for physicians to dictate) at the ambulatory care unit (ACU). However, again, the process flow related data was not available. The BCCA OR team, Pablo Santibáñez and Vincent Chow mapped the patient flow process, and then manually collected time and motion data to track the movement of patients and physicians. The data was used for a simulation model to evaluate different what-if scenarios: different appointment scheduling methods and room allocation methods. As a result, the team was able to achieve up to 70% reduction in patient appointment wait time with minimum impact on the clinical duration. They were also able to free up to 26% of the exam rooms to accommodate for other physician duties.

On the academic front, a Ph.D student at the Sauder School of Business in the University of BC, Antoine Sauré, has been helping BCCA in another department: Radiation Therapy treatment units. This research is motivated by the adverse effect of delays on patients’ health such as physical distress and deterioration of the quality of life, and the inefficiencies in the use of expensive resources. Rather than maximizing revenue, the main purpose of our work is to identify good scheduling policies for dynamically allocating available treatment capacity to incoming demand so as to achieve wait time targets in a cost-effective manner. Currently, the number of urgent treatments that would start after the recommended target time is significantly below the target. This goal involves the development of a Markov Decision Process model and simulation models for identifying and testing different types of policies. This is still an on-going research. No results are currently available. However, the team is ready to test algorithms for determining the optimal scheduling policy based on an affine approximation of the value function and a column generation algorithm to tackle the otherwise very large MDP problem.

The papers for the above two projects are available online at if you wish to obtain more information.

Credits: These 3 talks were given at the INFORMS 2008 conference in Washington DC. The track sessions were TB21, TB34, and TB34. Speakers are Ali Vahit Esensoy, University of Toronto, Canada; Pablo Santibanez, Operations Research Scientist, British Columbia Cancer Agency, Canada; and Antoine Saure, PhD Student, Sauder School of Business, University of British Columbia, Canada. The talks were titled "Evaluation of Ambulance Transfers into UCCs to Improve Ambulance Availability & Reduce Offload Delay", "Reducing Wait Times & Improving Resource Utilization at the BC Cancer Agency’s Ambulatory Care Unit", and "Radiation Therapy Treatment Scheduling".

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