Determining the impact of current Canadian stem cell registry policy on donor availability via dynamic registry simulation.

BACKGROUND AND OBJECTIVES: When a haematopoietic stem cell registry size is constrained by limits on recruiting, as in Canada, identifying the right person to recruit is a critical determinant of effectiveness. The aim of this study was to evaluate the impact of changes to donor recruitment effort, within ethnic groups, on the matching effectiveness of the Canadian registry as it evolves over time. MATERIALS AND METHODS: Simulation methods are applied to create a cohort of donor recruits and patients over a 10-year time horizon. New recruits are added to the registry each year, while some existing donors 'age-out' upon reaching their 36th birthday. In a similar fashion, simulated patient lists are created. At the end of each simulated year, simulated patients are matched against the simulated registry. RESULTS: There are increased matches in non-White populations when diverse registrants are preferentially recruited, but there are larger decreases in the number of matches for Caucasian patients. Additionally, ethnic communities that have limited registrants in the Canadian registry in 2021 do not benefit from increased recruiting efforts as much as communities with a larger initial number of registrants. CONCLUSION: Preferentially recruiting from non-Caucasian populations reduces the number of matches from Canadian sources because increases in non-Caucasian populations will not fully counterbalance decreases to Caucasian patient matches. Nevertheless, more than 80% of all matches are for Caucasian patients, regardless of the donor recruiting effort within ethnic groups.

The operational impact of introducing cold stored platelets.

BACKGROUND: Cold stored platelets (CSP) undergo physical changes that make them better at initiating a clot. While cold stored platelets are superior for reducing bleeding in actively bleeding patients, room temperature platelets (RTP) are better for increasing platelet count in patients requiring a prophylactic transfusion. However, whether the overhead required to maintain a dual platelet inventory of both RTP and CSP could be compensated by reduced platelet wastage resulting from the longer shelf life of CSP has not been determined. STUDY DESIGN AND METHODS: A simulation model of a regional blood supply was built, with focus on the operations of a case hospital. Two scenarios were considered: "No-CSP," in which the hospital issues only RTP, and "CSP," in which the hospital issues both RTP and CSP Within the CSP scenario, conditions were tested under which the hospital receives only RTP and converts some to cold stored platelets and a second strategy where the hospital receives CSP from the regional supplier in addition to converting RTP. RESULTS: A centralized supply of CSP is necessary since on-site conversion is limited by platelet age. Product shortages decrease with increased CSP inventory, but CSP wastage increases. It was also determined that, because relatively few RTP units can be converted on-site, RTP wastage is not significantly decreased with the introduction of CSP. CONCLUSION: Given the clinical benefits for treatment of trauma, CSP is a desirable addition to a blood formulary. However, it is unlikely that significant reductions in RTP wastage will occur because of the introduction of CSP.

Evaluating the inventory impact of utilizing low titer platelets in regional hospitals.

BACKGROUND: As a result of constrained supply, it is sometimes necessary to provide patients with ABO-mismatched platelets. Such practices increase the risk of acute hemolytic transfusion reaction (AHTR). Providing patients with platelets suspended in O plasma having low-titer Anti-A and Anti-B antibodies (LtABO) could reduce the incidence of AHTR. However, natural scarcity limits the number of such units that can be produced. In this paper we present a study to evaluate strategies for deploying LtABO at regional hospitals in Canada. STUDY DESIGN AND METHODS: Regional hospitals often experience demand for platelets on an irregular basis. They are, however, required to stock some number of platelets (typically one A-unit and one O-unit) for emergencies; outdates are common, with discard rates sometimes >>50%. A simulation study was completed to determine the impact of replacing a (1A, 1O) inventory with 2 or 3 units of LtABO at regional hospitals. RESULTS: A significant decreases in wastage and shortage can be expected by replacing a (1A, 1O) inventory policy with 2 units of LtABO. In tested cases, a 2-unit LtABO dominated a (1A, 1O) policy, resulting in statistically fewer outdates and instances of shortage. Holding 3 units of LtABO, increases product availability, but results in an increase in outdates when compared to a (1A, 1O) policy. CONCLUSION: Providing LtABO platelets to smaller, regional hospitals will lower wastage rates and improve patient access to care, when compared to existing (1A, 1O) inventory policies.

Modeling unrelated blood stem cell donor recruitment using simulated registrant cohorts: Assessment of human leukocyte antigen matching across ethnicity groups.

BACKGROUND: Human leukocyte antigen (HLA)-matched unrelated donors are not available for some patients considered for allogeneic hematopoietic cell transplantation, particularly among certain ethnic groups. Simulated recruitment modeling can inform efforts to find new matches for more patients. METHODS: Simulated recruits were generated by assigning a pair of donor HLA haplotypes from historical data files and matched against HLA data of patient searches in the Canadian Blood Services Stem Cell Registry. Recruitment cohorts reflected the proportion of five specific ethnic groups in the 2016 Canadian census data. RESULTS: Novel 8/8 HLA matches between simulated recruits and patients increased linearly with larger recruitment cohorts. The proportion of novel 8/8 HLA matches from Caucasian, Hispanic, and Native American/First Nations recruits was equal to or greater than their relative proportion in the recruited cohort (match to: recruit ratio (MRR) ≥ 1). In contrast, African American and Asian & Pacific Islander recruits represented a smaller proportion of novel matches relative to their percentage of the recruited cohort (MRR <1). The proportion of novel 7/8 HLA-matches from each ethnic group was approximately the same as their proportion in the recruited cohort (MRR ~ 1) and high rates of 7/8 HLA-matching already exist within the Canadian Blood Services registry for all ethnic groups. CONCLUSION: Continued large recruitment cohorts are needed to add new 8/8 HLA matches to registry inventories. Likelihoods of novel HLA matches varied across ethnic groups, reflecting varied HLA haplotype frequencies across groups. Simulated cohort modeling can inform recruitment strategies that will generate new donor options for patients.

The impact of donor ferritin testing on blood availability in Canada.

BACKGROUND AND OBJECTIVES: Iron depletion is a side effect of blood donation. Agencies have developed policies to test donors and to extend inter-donation intervals (IDIs) for individuals with low ferritin levels. Ferritin testing, however, has an impact on product availability due to longer IDIs and the effect of test results on donor behaviour. In this paper we apply a model to evaluate the impact of ferritin testing in the Canadian donor population on whole blood donations. MATERIALS AND METHODS: A discrete event simulation was adopted for the study. The model represents a population of individuals that donate blood, are tested for ferritin levels, and may exit the system. Data for the simulation was derived from operational data, donor research studies from Canadian Blood Services and previously published sources. RESULTS: Red cell collections will decline by at least 3.1% and could decline by as much as 19.2% after ferritin testing is put in place. Requirements for new donors could rise by as much as 36.0%. CONCLUSION: The impact of ferritin testing on repeat donor behaviour, rather than extensions to the mandated inter-donation interval, is the largest factor influencing declines in whole blood donations. Because behaviour changes following the receipt of a low ferritin result, blood agencies must ensure that donors with low ferritin are motivated to modify their lifestyle and, when healthy, return to the donor pool.

Estimating the impact on the inventory of implementing pathogen-reduced platelets in Canada.

BACKGROUND: Pathogen reduction (PR) technology will be implemented in pooled platelets in Canada. It is anticipated that PR platelets will be licensed in Canada for a maximum shelf life of 5 days, while non-treated apheresis platelet products will continue to be licensed for 7 days. STUDY DESIGN AND METHODS: This study evaluates the impact on inventory, wastage, and shortages of implementing PR platelets. A custom-built simulation model was used to represent a regional distribution network. Experiments with the model were used to estimate product wastage and shortages when a 5-day PR pooled platelet product is introduced alongside a 7-day apheresis platelet product. RESULTS: Pooled platelet waste and shortages both increase as pooled shelf life decreases. Apheresis platelets, however, show a different response: While shortages of apheresis platelets increase as the shelf life of pooled units decreases, apheresis waste declines as pooled shelf life decreases. CONCLUSION: Additional platelet collections will be necessary to accommodate the shorter PR platelet shelf life and to cover increased patient transfusion needs due to a lower platelet yield in PR units. Increases of 9% for pooled units and 6% for apheresis units beyond expected demand, were found to be sufficient to ensure a non-inferior level of customer service while minimizing waste.

Modeling rare blood in Canada.

BACKGROUND: Many countries maintain rare blood programs to provide access to blood for patients with complex serologies. These include a process to screen donors and a registry to record information about rare donors; blood agencies may also freeze some units. However, frozen blood is much more expensive than liquid blood. STUDY DESIGN AND METHODS: A two-phase approach to analysis was used to evaluate how rare a blood type must be before a frozen inventory is necessary and what screening rates are required to support a rare blood program. A simulation model was employed to evaluate the impact of inventory on patient access. RESULTS: Results suggested that, for 27 of 29 phenotypes managed by Canadian Blood Services, insufficient donors had been identified to ensure a stable inventory. Analytic results showed the screening rate necessary to ensure a stable inventory and the time frame to build a rare donor base. Twenty-nine simulation scenarios were executed to evaluate patient access to rare blood against inventory levels. Results show that some amount of frozen inventory is necessary for phenotypes rarer than 1 in 3000. However, holding more than two units apiece of O-, O+, A-, and A+ did not improve patient access. CONCLUSION: While some level of frozen blood is needed for rare blood, large inventories do not improve access. Modest amounts of frozen inventory, combined with increased door screening, provides the greatest chance of maximizing patient access.

Determining the inventory impact of extended-shelf-life platelets with a network simulation model.

BACKGROUND: The regulatory shelf life for platelets (PLTs) in many jurisdictions is 5 days. PLT shelf life can be extended to 7 days with an enhanced bacterial detection algorithm. Enhanced testing, however, comes at a cost, which may be offset by reductions in wastage due to longer shelf life. This article describes a method for estimating systemwide reductions in PLT outdates after PLT shelf life is extended. STUDY DESIGN AND METHODS: A simulation was used to evaluate the impact of an extended PLT shelf life within a national blood network. A network model of the Canadian Blood Services PLT supply chain was built and validated. PLT shelf life was extended from 5 days to 6, 7, and 8 days and runs were completed to determine the impact on outdates. RESULTS: Results suggest that, in general, a 16.3% reduction in PLT wastage can be expected with each additional day that PLT shelf life is extended. Both suppliers and hospitals will experience fewer outdating units, but wastage will decrease at a faster rate at hospitals. No effect was seen by blood group, but there was some evidence that supplier site characteristics influences both the number of units wasted and the site's ability to benefit from extended-shelf-life PLTs. CONCLUSION: Extended-shelf-life PLTs will reduce wastage within a blood supply chain. At 7 days, an improvement of 38% reduction in wastage can be expected with outdates being equally distributed between suppliers and hospital customers.

Understanding the Effects of Competition for Constrained Colonoscopy Services with the Introduction of Population-level Colorectal Cancer Screening.

BACKGROUND: Median wait times for gastroenterology services in Canada exceed consensus-recommended targets and have worsened substantially over the past decade. Meanwhile, efforts to control colorectal cancer have shifted their focus to screening asymptomatic, average-risk individuals. Along with increasing prevalence of colorectal cancer due to an aging population, screening programs are expected to add substantially to the existing burden on colonoscopy services, and create competition for limited services among individuals of varying risk. Failure to understand the effects of operational programmatic screening decisions may cause unintended harm to both screening participants and higher-risk patients, make inefficient use of limited health care resources, and ultimately hinder a program's success. METHODS: We present a new simulation model (Simulation of Cancer Outcomes for Planning Exercises, or SCOPE) for colorectal cancer screening which, unlike many other colorectal cancer screening models, reflects the effects of competition for limited colonoscopy services between patient groups and can be used to guide planning to ensure adequate resource allocation. We include verification and validation results for the SCOPE model. RESULTS: A discrete event simulation model was developed based on an epidemiological representation of colorectal cancer in a sample population. Colonoscopy service and screening modules were added to allow observation of screening scenarios and resource considerations. The model reproduces population-based data on prevalence of colorectal cancer by stage, and mortality by cause of death, age, and sex, and attendant demand and wait times for colonoscopy services. CONCLUSIONS: The study model differs from existing screening models in that it explicitly considers the colonoscopy resource implications of screening activities and the impact of constrained resources on screening effectiveness.

Determining staffing requirements for blood donor clinics: the Canadian Blood Services experience.

BACKGROUND: Canadian Blood Services runs approximately 16,000 donor clinics annually. While there were more than 220 different clinic configurations used in 2011 and 2012, 67% of all clinic configurations followed one of 51 standard models. As part of operational planning for current and future configurations it was necessary for Canadian Blood Services to calculate staffing requirements for standard clinic models. STUDY DESIGN AND METHODS: In this article we present a method that incorporates both cost control and impact on donor experience. We calculate staffing requirements to minimize costs, but adjust using queuing theory to ensure donor wait time metrics are met. The method can be applied in a wide variety of situations. RESULTS: Although developed for a particular study, the methods described in this article can be applied in a wide variety of situations. A case study in which the model is used to review existing staffing arrangements at Canadian Blood Services is presented. CONCLUSION: The staffing model can be used to balance the requirements of minimizing staffing costs with that of ensuring that donors do not suffer unnecessary delays. Moreover, in an example application, savings of 3.4% were identified through the modeling process.

Déjà-vu all over again: using simulation to evaluate the impact of shorter shelf life for red blood cells at Héma-Québec.

BACKGROUND: Since the 1970s red blood cells (RBCs) have had a rated shelf life of 42 days. Recently, studies have suggested poorer patient outcomes when older blood is transfused. However, shortening the shelf life of RBCs may increase costs and lead to greater instances of outdates and shortages. STUDY DESIGN AND METHODS: A simulation method to evaluate the impact of a shorter shelf life for RBCs on a regional blood network was developed. A network model of the production and distribution system in the province of Quebec was built and validated. RESULTS: The model suggests that a shelf life of 21 or 28 days will have modest impact on outdate and shortage rates. A shelf life of 14 days will create significant challenges for both blood suppliers and hospitals and will result in systemwide outdate rates of 6.64% and shortage rates of 2.75%. The impact of a shorter shelf life for RBCs will disproportionately affect smaller and midsize hospitals. CONCLUSION: A shelf life of 28 or 21 days is feasible without excessive increases to systemwide outdate, shortage, or emergency ordering rates. Large hospitals will see minimal impact; smaller hospitals will see larger increases and may be unable to find inventory policies that maintain both low outdate and shortage rates. Reducing the shelf life to 14 days, or lower, results in significant challenges for suppliers and hospitals of all sizes. All hospitals will see an impact on outdate and shortage rates; overall systemwide outdate rates (6% or more) will reach levels that would currently be considered unacceptably high.

A comprehensive simulation for wait time reduction and capacity planning applied in general surgery.

This paper describes the use of operational research techniques to analyze the wait list for the Division of General Surgery at the Capital District Health Authority in Halifax, Nova Scotia, Canada. A discrete event simulation model was developed to aid capacity planning decisions and to analyze the performance of the division. The analysis examined the consequences of redistributing beds between sites, and achieving standard patient lengths of stay, while contrasting them to current and additional resource options. From the results, multiple independent and combined options for stabilizing and decreasing waits for elective procedures were proposed.

Shooting arrows in the dark: the policies and practices of waitlist management in Canada.

Wait times for medical procedures in Canada are universally thought to be too long, particularly for elective procedures. In this paper we point out the conceptual and practical difficulties surrounding wait list management in Canada. We suggest that while waits need to exist as a distributive allocation policy, the data to make informed decisions about wait times and their impact on patient care is absent. We also show that current waitlist initiatives lack an underlying conceptual model of why waits occur. The paper concludes with a discussion of why operational research (OR) models are not in greater use for wait list management and suggest a program of research to improve knowledge uptake for OR models.

Sampling error can significantly affect measured hospital financial performance of surgeons and resulting operating room time allocations.

UNLABELLED: Hospitals with limited operating room (OR) hours, those with intensive care unit or ward beds that are always full, or those that have no incremental revenue for many patients need to choose which surgeons get the resources. Although such decisions are based on internal financial reports, whether the reports are statistically valid is not known. Random error may affect surgeons' measured financial performance and, thus, what cases the anesthesiologists get to do and which patients get to receive care. We tested whether one fiscal year of surgeon-specific financial data is sufficient for accurate financial accounting. We obtained accounting data for all outpatient or same-day-admit surgery cases during one fiscal year at an academic medical center. Linear programming was used to find the mix of surgeons' OR time allocations that would maximize the contribution margin or minimize variable costs. Confidence intervals were calculated on these end points by using Fieller's theorem and Monte-Carlo simulation. The 95% confidence intervals for increases in contribution margins or reductions in variable costs were 4.3% to 10.8% and 6.0% to 8.9%, respectively. As many as 22% of surgeons would have had OR time reduced because of sampling error. We recommend that physicians ask for and OR managers get confidence intervals of end points of financial analyses when making decisions based on them. IMPLICATIONS: The common approach of using one fiscal year of perioperative accounting data can be insufficient to prevent random error from influencing important management decisions. When accounting data are used for hospital and operating room management decision making, confidence intervals should be calculated for the key financial variables (e.g., variable cost per hour of operating room time).

Use of linear programming to estimate impact of changes in a hospital's operating room time allocation on perioperative variable costs.

BACKGROUND: Administrators at hospitals with a fixed annual budget may want to focus surgical services on priority areas to ensure its community receives the best health services possible. However, many hospitals lack the detailed managerial accounting data needed to ensure that such a change does not increase operating costs. The authors used a detailed hospital cost database to investigate by how much a change in allocations of operating room (OR) time among surgeons can increase perioperative variable costs. METHODS: The authors obtained financial data for all patients who underwent outpatient or same-day admit surgery during a year. Linear programming was used to determine by how much changing the mix of surgeons can increase total variable costs while maintaining the same total hours of OR time for elective cases. RESULTS: Changing OR allocations among surgeons without changing total OR hours allocated will likely increase perioperative variable costs by less than 34%. If, in addition, intensive care unit hours for elective surgical cases are not increased, hospital ward occupancy is capped, and implant use is tracked and capped, perioperative costs will likely increase by less than 10%. These four variables predict 97% of the variance in total variable costs. CONCLUSIONS: The authors showed that changing OR allocations among surgeons without changing total OR hours allocated can increase hospital perioperative variable costs by up to approximately one third. Thus, at hospitals with fixed or nearly fixed annual budgets, allocating OR time based on an OR-based statistic such as utilization can adversely affect the hospital financially. The OR manager can reduce the potential increase in costs by considering not just OR time, but also the resulting use of hospital beds and implants.

Operating room managers' use of integer programming for assigning block time to surgical groups: a case study.

UNLABELLED: A common problem at hospitals with fixed amounts of available operating room (OR) time (i.e., "block time") is determining an equitable method of distributing time to surgical groups. Typically, facilities determine a surgical group's share of available block time using formulas based on OR utilization, contribution margin, or some other performance metric. Once each group's share of time has been calculated, a method must be found for fitting each group's allocated OR time into the surgical master schedule. This involves assigning specific ORs on specific days of the week to specific surgical groups, usually with the objective of ensuring that the time assigned to each group is close to its target share. Unfortunately, the target allocated to a group is rarely expressible as a multiple of whole blocks. In this paper, we describe a hospital's experience using the mathematical technique of integer programming to solve the problem of developing a consistent schedule that minimizes the shortfall between each group's target and actual assignment of OR time. Schedule accuracy, the sum over all surgical groups of shortfalls divided by the total time available on the schedule, was 99.7% (SD 0.1%, n = 11). Simulations show the algorithm's accuracy can exceed 97% with > or =4 ORs. The method is a systematic and successful way to assign OR blocks to surgeons. IMPLICATIONS: At hospitals with a fixed budget of operating room (OR) time, integer programming can be used by OR managers to decide which surgical group is to be allocated which OR on which day(s) of the week. In this case study, we describe the successful application of integer programming to this task, and discuss the applicability of the results to other hospitals.

Calculating a potential increase in hospital margin for elective surgery by changing operating room time allocations or increasing nursing staffing to permit completion of more cases: a case study.

UNLABELLED: Administrators routinely seek to increase contribution margin (revenue minus variable costs) to better cover fixed costs, provide indigent care, and meet other community service responsibilities. Hospitals with high operating room (OR) utilizations can allocate OR time for elective surgery to surgeons based partly on their contribution margins per hour of OR time. This applies particularly when OR caseload is limited by nursing recruitment. From a hospital's annual accounting data for elective cases, we calculated the following for each surgeon's patients: variable costs for the entire hospitalization or outpatient visit, revenues, hours of OR time, hours of regular ward time, and hours of intensive care unit (ICU) time. The contribution margin per hour of OR time varied more than 1000% among surgeons. Linear programming showed that reallocating OR time among surgeons could increase the overall hospital contribution margin for elective surgery by 7.1%. This was not achieved simply by taking OR time from surgeons with the smallest contribution margins per OR hour and giving it to the surgeons with the largest contribution margins per OR hour because different surgeons used differing amounts of hospital ward and ICU time. We conclude that to achieve substantive improvement in a hospital's perioperative financial performance despite restrictions on available OR, hospital ward, or ICU time, contribution margin per OR hour should be considered (perhaps along with OR utilization) when OR time is allocated. IMPLICATIONS: For hospitals where elective surgery caseload is limited by nursing recruitment, to increase one surgeon's operating room time either another surgeon's time must be decreased, nurses need to be paid a premium for working longer hours, or higher-priced "traveling" nurses can be contracted. Linear programming was performed using Microsoft Excel to estimate the effect of each of these interventions on hospital contribution margin.