Spatio-Temporal Clustering of Multi-Location Time Series to Model Seasonal Influenza Spread.

Although seasonal influenza disease spread is a spatio-temporal phenomenon, public surveillance systems aggregate data only spatially, and are rarely predictive. We develop a hierarchical clustering-based machine learning tool to anticipate flu spread patterns based on historical spatio-temporal flu activity, where we use historical influenza-related emergency department records as a proxy for flu prevalence. This analysis replaces conventional geographical hospital clustering with clusters based on both spatial and temporal distance between hospital flu peaks to generate a network illustrating whether flu spreads between pairs of clusters (direction) and how long that spread takes (magnitude). To overcome data sparsity, we take a model-free approach, treating hospital clusters as a fully-connected network, where arcs indicate flu transmission. We perform predictive analysis on the clusters' time series of flu ED visits to determine direction and magnitude of flu travel. Detection of recurrent spatio-temporal patterns may help policymakers and hospitals better prepare for outbreaks. We apply this tool to Ontario, Canada using a five-year historical dataset of daily flu-related ED visits, and find that in addition to expected flu spread between major cities/airport regions, we were able to illuminate previously unsuspected patterns of flu spread between non-major cities, providing new insights for public health officials. We showed that while a spatial clustering outperforms a temporal clustering in terms of the direction of the spread (81% spatial v. 71% temporal), the opposite is true in terms of the magnitude of the time lag (20% spatial v. 70% temporal).

Internet of things in healthcare for patient safety: an empirical study.

INTRODUCTION: This study evaluates the impact of an Internet of Things (IoT) intervention in a hospital unit and provides empirical evidence on the effects of smart technologies on patient safety (patient falls and hand hygiene compliance rate) and staff experiences. METHOD: We have conducted a post-intervention analysis of hand hygiene (HH) compliance rate, and a pre-and post-intervention interrupted time-series (ITS) analysis of the patient falls rates. Lastly, we investigated staff experiences by conducting semi-structured open-ended interviews based on Roger's Diffusion of Innovation Theory. RESULTS: The results showed that (i) there was no statistically significant change in the mean patient fall rates. ITS analysis revealed non-significant incremental changes in mean patient falls (- 0.14 falls/quarter/1000 patient-days). (ii) HH compliance rates were observed to increase in the first year then decrease in the second year for all staff types and room types. (iii) qualitative interviews with the nurses reported improvement in direct patient care time, and a reduced number of patient falls. CONCLUSION: This study provides empirical evidence of some positive changes in the outcome variables of interest and the interviews with the staff of that unit reported similar results as well. Notably, our observations identified behavioral and environmental issues as being particularly important for ensuring success during an IoT innovation implementation within a hospital setting.

Evaluation framework for automatic privacy auditing tools for hospital data breach detections: A case study.

OBJECTIVE: We aim to 1) design an evaluation framework to examine the accuracy of automatic privacy auditing tools, 2) apply the evaluation method at a hospital to validate the performance of an auditing tool that uses a machine learning algorithm to automate user access auditing, and 3) recommend further improvements in auditing for the hospital. MATERIALS AND METHODS: Using the black box method of user acceptance testing, we have designed an evaluation framework consisting of appropriate and inappropriate behaviour scenarios to examine the privacy auditing tools. The scenarios were designed from clinical and non-clinical hospital staff perspective, taking expert opinions from the privacy officers and considering examples from the Information and Privacy Commission (IPC) and were tested using Mackenzie Richmond Hill Hospital's data. RESULTS: The case study using this evaluation framework found that on average 98.09 % of total accesses of the hospital were identified as appropriate and the tool was unable to explain the remaining 1.91 % of accesses. In addition, a statistically significant (P < 0.05) increasing trend on categorizing appropriate accesses by the tool have been observed. Furthermore, an analysis of unexplained accesses revealed the contributing factors and found issues related to hospital workflows and data quality (information was missing about staff roles and departments). CONCLUSION: Given that adoption of these machine learning tools is increasing in hospitals, this research provides an evaluation framework and an empirical evidence on the effectiveness of automated privacy auditing and detecting anomalies for dynamic hospital workflows.

Discharge destination following hip fracture: comparative effectiveness and cost analyses.

This study determines outcomes and costs of similar hip fracture patients that were discharged from hospital to a rehabilitation facility or to the community within 1 year. Community patients had worse outcomes and lower costs compared to rehabilitation facility patients. This study contributes to understanding hip fracture quality of care. PURPOSE: The purpose of this study is to determine the impact on mortality and rehospitalization, as well as health system cost, of similar hip fracture patients being discharged to an inpatient rehabilitation facility or directly to the community within 1 year in Ontario, Canada. METHODS: This was a retrospective study of a propensity-matched cohort completed from the health system perspective. Administrative databases were used to identify and match two groups of older adults (total n = 18,773) discharged alive from acute care for hip fracture repair: patients discharged to inpatient rehabilitation were matched to patients discharged to the community. RESULTS: A higher proportion of patients discharged to the community (27-42%) died or were rehospitalized (SDhighipr = 0.21, SDlowipr = 0.33) and had substantially lower health system costs (SDhighipr = 0.65, SDlowipr = 0.42) up to 1 year post-acute discharge compared to similar patients discharged to inpatient rehabilitation facilities (IPR) (10-11%). CONCLUSIONS: This study demonstrates that similar hip fracture patients are discharged to different post-acute settings (i.e., home-based rehabilitation and inpatient rehabilitation) and have different outcomes, thereby calling into question the appropriateness of post-acute rehabilitation delivery in Ontario, Canada. Future research should focus on determining how trade-offs in resource allocation between settings would impact patient outcomes.

Post-acute pathways among hip fracture patients: a system-level analysis.

BACKGROUND: Hip fractures among older adults are one of the leading causes of hospitalization and result in significant morbidity, mortality, and health care use. Guidelines suggest that rehabilitation after surgery is imperative to return patients to pre-morbid function. However, post-acute care (which encompasses rehabilitation) is currently delivered in a multitude of settings, and there is a lack of evidence with regards to which hip fracture patients should use which post-acute settings. The purpose of this study is to describe hip fracture patient characteristics and the most common post-acute pathways within a 1-year episode of care, and to examine how these vary regionally within a health system. METHODS: This study took place in the province of Ontario, Canada, which has 14 health regions and universal health coverage for all residents. Administrative health databases were used for analyses. Community-dwelling patients aged 66 and over admitted to an acute care hospital for hip fracture between April 2008 and March 2013 were identified. Patients' post-acute destinations within each region were retrieved by linking patients' records within various institutional databases using a unique encoded identifier. Post-acute pathways were then characterized by determining when each patient went to each post-acute destination within one year post-discharge from acute care. Differences in patient characteristics between regions were detected using standardized differences and p-values. RESULTS: Thirty-six thousand twenty nine hip fracture patients were included. The study cohort was 71.9 % female with a mean age of 82.9 (±7.5SD). There was significant variation between regions with respect to the immediate post-acute discharge destination: four regions discharged a substantially higher proportion of their patients to inpatient rehabilitation compared to all others. However, the majority of patient characteristics between those four regions and all other regions did not significantly differ. There were 49 unique post-acute pathways taken by patients, with the largest proportion of patients admitted to either community-based or short-term institutionalized rehabilitation, regardless of region. CONCLUSIONS: The observation that similar hip fracture patients are discharged to different post-acute settings calls into question both the appropriateness of care delivered in the post-acute period and health system expenditures. As policy makers continue to develop performance-based funding models to increase accountability of institutions in the provision of quality care to hip fracture patients, ensuring patients receive appropriate rehabilitative care is a priority for health system planning.

Comparison of Mechanical Allodynia and Recovery of Locomotion and Bladder Function by Different Parameters of Low Thoracic Spinal Contusion Injury in Rats.

BACKGROUND: The present study was designed to examine the functional recovery following spinal cord injury (SCI) by adjusting the parameters of impact force and dwell-time using the Infinite Horizon (IH) impactor device. METHODS: Sprague-Dawley rats (225-240 g) were divided into eight injury groups based on force of injury (Kdyn) and dwell time (seconds), indicated as Force-Dwell time: 150-4, 150-3, 150-2, 150-1, 150-0, 200-0, 90-2 and sham controls, respectively. RESULTS: After T10 SCI, higher injury force produced greater spinal cord displacement (P < 0.05) and showed a significant correlation (r = 0.813) between the displacement and the force (P < 0.05). In neuropathic pain-like behavior, the percent of paw withdrawals scores in the hindpaw for the 150-4, 150-3, 150-2, 150-1 and the 200-0 injury groups were significantly lowered compared with sham controls (P < 0.05). The recovery of locomotion had a significant within-subjects effect of time (P < 0.05) and the 150-0 group had increased recovery compared to other groups (P < 0.05). In addition, the 200-0 and the 90-2 recovered significantly better than all the 150 kdyn impact groups that included a dwell-time (P < 0.05). In recovery of spontaneous bladder function, the 150-4 injury group took significantly longer recovery time whereas the 150-0 and the 90-2 groups had the shortest recovery times. CONCLUSIONS: The present study demonstrates SCI parameters optimize development of mechanical allodynia and other pathological outcomes.

Can hospitals compete on quality? Hospital competition.

In this paper, we consider two hospitals with different perceived quality of care competing to capture a fraction of the total market demand. Patients select the hospital that provides the highest utility, which is a function of price and the patient's perceived quality of life during their life expectancy. We consider a market with a single class of patients and show that depending on the market demand and perceived quality of care of the hospitals, patients may enjoy a positive utility. Moreover, hospitals share the market demand based on their perceived quality of care and capacity. We also show that in a monopoly market (a market with a single hospital) the optimal demand captured by the hospital is independent of the perceived quality of care. We investigate the effects of different parameters including the market demand, hospitals' capacities, and perceived quality of care on the fraction of the demand that each hospital captures using some numerical examples.

Dynamic optimization of chemotherapy outpatient scheduling with uncertainty.

Chemotherapy outpatient scheduling is a complex, dynamic, uncertain problem. Chemotherapy centres are facing increasing demands and they need to increase their efficiency; however there are very few studies looking at using optimization technology on the chemotherapy scheduling problem. We address dynamic uncertainty that arises from requests for appointments that arrive in real time and uncertainty due to last minute scheduling changes. We propose dynamic template scheduling, a novel technique that combines proactive and online optimization and we apply it to the chemotherapy outpatient scheduling problem. We create a proactive template of an expected day in the chemotherapy centre using a deterministic optimization model and a sample of appointments. As requests for appointments arrive, we use the template to schedule them. When a request arrives that does not fit the template, we update the template online using the optimization model and a revised set of appointments. To accommodate last minute additions and cancellations to the schedule, we propose a shuffling algorithm that moves appointment start times within a predefined time limit. We test the use of dynamic template scheduling against the optimal offline solution and the actual performance of the cancer centre. We find improvements in makespan of up to 20 % when using dynamic template scheduling compared to current practice.

Theory of constraints for publicly funded health systems.

Originally developed in the context of publicly traded for-profit companies, theory of constraints (TOC) improves system performance through leveraging the constraint(s). While the theory seems to be a natural fit for resource-constrained publicly funded health systems, there is a lack of literature addressing the modifications required to adopt TOC and define the goal and performance measures. This paper develops a system dynamics representation of the classical TOC's system-wide goal and performance measures for publicly traded for-profit companies, which forms the basis for developing a similar model for publicly funded health systems. The model is then expanded to include some of the factors that affect system performance, providing a framework to apply TOC's process of ongoing improvement in publicly funded health systems. Future research is required to more accurately define the factors affecting system performance and populate the model with evidence-based estimates for various parameters in order to use the model to guide TOC's process of ongoing improvement.

Allocating funds for HIV/AIDS: a descriptive study of KwaDukuza, South Africa.

OBJECTIVE: through a descriptive study, we determined the factors that influence the decision-making process for allocating funds to HIV/AIDS prevention and treatment programmes, and the extent to which formal decision tools are used in the municipality of KwaDukuza, South Africa. METHODS: we conducted 35 key informant interviews in KwaDukuza. The interview questions addressed specific resource allocation issues while allowing respondents to speak openly about the complexities of the HIV/AIDS resource allocation process. RESULTS: donors have a large influence on the decision-making process for HIV/AIDS resource allocation. However, advocacy groups, governmental bodies and local communities also play an important role. Political power, culture and ethics are among a set of intangible factors that have a strong influence on HIV/AIDS resource allocation. Formal methods, including needs assessment, best practice approaches, epidemiologic modelling and cost-effectiveness analysis are sometimes used to support the HIV/AIDS resource allocation process. Historical spending patterns are an important consideration in future HIV/AIDS allocation strategies. CONCLUSIONS: several factors and groups influence resource allocation in KwaDukuza. Although formal economic and epidemiologic information is sometimes used, in most cases other factors are more important for resource allocation decision-making. These other factors should be considered in any attempts to improve the resource allocation processes.

Modeling the cardiac surgery workforce in Canada.

BACKGROUND: Limited employment opportunities for recently trained cardiac surgeons are deterring medical students from entering cardiac surgery residency programs. Given the lengthy training period and the aging of both the general population and currently practicing cardiac surgeons, this reduced enrollment raises concerns about the adequacy of the future cardiac surgery workforce. A workforce model was developed to explore the future need for cardiac surgeons in Canada. METHODS: A novel system dynamics model was developed to simulate the supply and demand for cardiac surgery in Canada between 2008 and 2030 to identify whether an excess or shortage of surgeons would exist. Several different scenarios were examined, including varying surgeon productivity, revascularization rates, and residency enrollment rates. RESULTS: The simulation results of various scenarios are presented. In the base case, a surgeon shortage is expected to develop by 2025, although this depends on surgeons' response to demand-supply gap changes. An alternative scenario in which residency enrollment directly relates to the presence of unemployed surgeons also projects substantial shortages after 2021. The model results indicate that if residency enrollment rates remain at the 2009 level an alarming shortage may develop soon, possibly reaching almost 50% of the Canadian cardiac surgical workforce. CONCLUSIONS: These workforce model results project an eventual cardiac surgeon shortage in Canada. This study highlights the possibility of a crisis in cardiac surgery and emphasizes the urgency with which enrollment into cardiac surgery training programs and the employability of recently trained cardiac surgery graduates need to be addressed.

Effect of anesthesia and sedation on pediatric MR imaging patient flow.

PURPOSE: To determine the effect of sedative and anesthetic administration on the duration and costs of pediatric magnetic resonance (MR) imaging. MATERIALS AND METHODS: This prospective study was approved by the institutional research ethics board; informed consent and/or assent was obtained from all participants or their parents. A patient flow study was conducted in a pediatric MR imaging clinic in which research assistants tracked participants' progress through the clinic. Demographic, visit process, and medication information was collected for 237 participants, categorized as awake, sedated, or anesthetized. The data were analyzed to (a) determine total visit duration differences, (b) investigate variations in visit stage durations according to patient type, and (c) estimate visit costs on the basis of human resource and medication use. Linear regression, the Shapiro-Wilk test, the two-tailed t test, and the nonparametric Mann-Whitney test were used. RESULTS: Complete data sets were obtained for 148 awake, 28 sedated, and 27 anesthetized participants. Data revealed 12 stage sequences among patient visits; dominant sequences differed according to patient category. An awake patient's average visit duration (2 hours 21 minutes) differed significantly from that of sedated (3 hours 38 minutes, P < .001) and anesthetized (4 hours 7 minutes, P < .001) patients; sedated and anesthetized visit durations did not differ significantly (P < .073), although this finding may be attributable to the small sample sizes. Variation in stage durations was also evident within and among patient types. Visit costs for sedated and anesthetized patients were 3.24 and 9.56 times higher, respectively, than those for awake patients. Costs for anesthetized patients were 2.95 times higher than those for sedated patients. CONCLUSION: Visit durations were significantly longer for anesthetized and sedated patients. Anesthetized patients incurred the highest costs, followed by sedated patients.

Understanding hospital and emergency department congestion: an examination of inpatient admission trends and bed resources.

OBJECTIVE: Patients in the emergency department (ED) who have been admitted to hospital (inpatient "boarders") are associated with ED overcrowding. They are also a symptom of a hospital-wide imbalance between demand and supply of resources. We analyzed the trends of inpatient admissions, ED boarding volumes, lengths of stay and bed resources of 3 major admitting services at our teaching institution. METHODS: We used hospital databases from Jan. 1, 2004, to Dec. 31, 2007, to analyze ED visits that resulted in admission to hospital. RESULTS: During the study period, 21 986 ED patients were admitted to hospital. The percentage of cancer-related admissions to the oncology admitting service decreased from 48% in 2004 to 24% in 2007, and admissions to general internal medicine (GIM) increased nearly 2-fold, from 28% in 2004 to 54% in 2007. In addition, GIM admitted about 10% more myocardial infarction and heart failure patients than did cardiology. General internal medicine constituted the majority of ED boarders and had a median boarding length of stay of approximately 15 hours. Inpatient beds on oncology and cardiology services remained static. CONCLUSION: Without bed capacity to admit more patients, our specialty services relied on GIM to serve as a safety net. At the same time, GIM was cited as a main source of ED congestion as their patients occupied more ED beds for longer periods than any other admitting service. The data presented in this study has helped effect positive change within our institution. Other hospitals running at or near capacity and faced with similar ED congestion may apply the methods we used in this study to analyze the cause and nature of their situation.

Physician workload and the Canadian Emergency Department Triage and Acuity Scale: the Predictors of Workload in the Emergency Room (POWER) Study.

INTRODUCTION: The Canadian Emergency Department Triage and Acuity Scale (CTAS) is a 5-level triage tool used to determine the priority by which patients should be treated in Canadian emergency departments (EDs). To determine emergency physician (EP) workload and staffing needs, many hospitals in Ontario use a case-mix formula based solely on patient volume at each triage level. The purpose of our study was to describe the distribution of EP time by activity during a shift in order to estimate the amount of time required by an EP to assess and treat patients in each triage category and to determine the variability in the distribution of CTAS scoring between hospital sites. METHODS: Research assistants directly observed EPs for 592 shifts and electronically recorded their activities on a moment-by-moment basis. The duration of all activities associated with a given patient were summed to derive a directly observed estimate of the amount of EP time required to treat the patient. RESULTS: We observed treatment times for 11 716 patients in 11 hospital-based EDs. The mean time for physicians to treat patients was 73.6 minutes (95% confidence interval [CI] 63.6-83.7) for CTAS level 1, 38.9 minutes (95% CI 36.0-41.8) for CTAS-2, 26.3 minutes (95% CI 25.4-27.2) for CTAS-3, 15.0 minutes (95% CI 14.6-15.4) for CTAS-4 and 10.9 minutes (95% CI 10.1-11.6) for CTAS-5. Physician time related to patient care activities accounted for 84.2% of physicians' ED shifts. CONCLUSION: In our study, EPs had very limited downtime. There was significant variability in the distribution of CTAS scores between sites and also marked variation in EP time related to each triage category. This brings into question the appropriateness of using CTAS alone to determine physician staffing levels in EDs.

How much do operational processes affect hospital inpatient discharge rates?

BACKGROUND: The objective of this study is to determine the effect of day of the week, holiday, team admission and rotation schedules, individual attending physicians and their length of coverage on daily team discharge rates. METHODS: We conducted a retrospective analysis of the General Internal Medicine (GIM) inpatient service at our institution for years 2005 and 2006, which included 5088 patients under GIM care. RESULTS: Weekend discharge rate was more than 50% lower compared with reference rates whereas Friday rates were 24% higher. Holiday Monday discharge rates were 65% lower than regular Mondays, with an increase in pre-holiday discharge rates. Teams that were on-call or that were on call the next day had 15% higher discharge rates compared with reference whereas teams that were post-call had 20% lower rates. Individual attending physicians and length of attending coverage contributed small variations in discharge rates. Resident scheduling was not a significant predictor of discharge rates. CONCLUSIONS: Day of the week and holidays followed by team organization and scheduling are significant predictors of daily variation in discharge rates. Introducing greater holiday and weekend capacity as well as reorganizing internal processes such as admitting and attending schedules may potentially optimize discharge rates.

S4HARA: System for HIV/AIDS resource allocation.

BACKGROUND: HIV/AIDS resource allocation decisions are influenced by political, social, ethical and other factors that are difficult to quantify. Consequently, quantitative models of HIV/AIDS resource allocation have had limited impact on actual spending decisions. We propose a decision-support System for HIV/AIDS Resource Allocation (S4HARA) that takes into consideration both principles of efficient resource allocation and the role of non-quantifiable influences on the decision-making process for resource allocation. METHODS: S4HARA is a four-step spreadsheet-based model. The first step serves to identify the factors currently influencing HIV/AIDS allocation decisions. The second step consists of prioritizing HIV/AIDS interventions. The third step involves allocating the budget to the HIV/AIDS interventions using a rational approach. Decision-makers can select from several rational models of resource allocation depending on availability of data and level of complexity. The last step combines the results of the first and third steps to highlight the influencing factors that act as barriers or facilitators to the results suggested by the rational resource allocation approach. Actionable recommendations are then made to improve the allocation. We illustrate S4HARA in the context of a primary healthcare clinic in South Africa. RESULTS: The clinic offers six types of HIV/AIDS interventions and spends US$750,000 annually on these programs. Current allocation decisions are influenced by donors, NGOs and the government as well as by ethical and religious factors. Without additional funding, an optimal allocation of the total budget suggests that the portion allotted to condom distribution be increased from 1% to 15% and the portion allotted to prevention and treatment of opportunistic infections be increased from 43% to 71%, while allocation to other interventions should decrease. CONCLUSION: Condom uptake at the clinic should be increased by changing the condom distribution policy from a pull system to a push system. NGOs and donors promoting antiretroviral programs at the clinic should be sensitized to the results of the model and urged to invest in wellness programs aimed at the prevention and treatment of opportunistic infections. S4HARA differentiates itself from other decision support tools by providing rational HIV/AIDS resource allocation capabilities as well as consideration of the realities facing authorities in their decision-making process.

A decision tool for negotiating home care funding levels in Ontario.

This paper describes a decision tool created for the Simcoe County Community Care Access Center (SCCCAC) in Ontario. The tool allows the SCCCAC to quantitatively assess the trade-offs between cost, quality, and waiting time of their home care patients. This information can then be used to negotiate reasonable funding levels with the Ontario government and to appropriately allocate this funding among the various patient groups at the SCCCAC. This work can be expanded to other health care organizations that use prioritized waiting lists.

Filtered optical feedback induced frequency dynamics in semiconductor lasers.

We demonstrate experimentally and numerically that, by spectrally filtering the delayed optical feedback into a semiconductor laser, one can elicit novel dynamics in the frequency of the laser output light on a time scale that is set by the delay time of the feedback. In particular, we show that through a judicious choice of the filter bandwidth, and its frequency relative to that of the laser, one can produce controlled oscillations in the frequency of light from the laser.