Developing an efficient scheduling template of a chemotherapy treatment unit: A case study

This study was undertaken to improve the performance of a Chemotherapy Treatment Unit by increasing the throughput and reducing the average patient's waiting time. In order to achieve this objective, a scheduling template has been built. The scheduling template is a simple tool that can be used to schedule patients' arrival to the clinic. A simulation model of this system was built and several scenarios, that target match the arrival pattern of the patients and resources availability, were designed and evaluated. After performing detailed analysis, one scenario provide the best system's performance. A scheduling template has been developed based on this scenario. After implementing the new scheduling template, 22.5% more patients can be served. 1.

INTRODUCTION

CancerCare Manitoba is a provincially mandated cancer care agency. It is dedicated to provide quality care to those who have been diagnosed and are living with cancer. MacCharles Chemotherapy unit is specially built to provide chemotherapy treatment to the cancer patients of Winnipeg. In order to maintain an excellent service, it tries to ensure that patients get their treatment in a timely manner. It is challenging to maintain that goal because of the lack of a proper roster, the workload distribution and inefficient resource allotment. In order to maintain the satisfaction of the patients and the healthcare providers, by serving the maximum number of patients in a timely manner, it is necessary to develop an efficient scheduling template that matches the required demand with the availability of resources. This goal can be reached using simulation modelling. Simulation has proven to be an excellent modelling tool. It can be defined as building computer models that represent real world or hypothetical systems, and hence experimenting with these models to study system behaviour under different scenarios.1, 2 A study was undertaken at the Children's Hospital of Eastern Ontario to identify the issues behind the long waiting time of a emergency room.3 A 20---day field observation revealed that the availability of the staff physician and interaction affects the patient wait time. Jyväskylä et al.4 used simulation to test different process scenarios, allocate resources and perform activity---based cost analysis in the Emergency Department (ED) at the Central Hospital. The simulation also supported the study of a new operational method, named "triage-team" method without interrupting the main system. The proposed triage team method categorises the entire patient according to the urgency to see the doctor and allows the patient to complete the necessary test before being seen by the doctor for the first time. The simulation study showed that it will decrease the throughput time of the patient and reduce the utilisation of the specialist and enable the ordering all the tests the patient needs right after arrival, thus quickening the referral to treatment. Santibáñez et al.5 developed a discrete event simulation model of British Columbia Cancer Agency"s ambulatory care unit which was used to study the impact of scenarios considering different operational factors (delay in starting clinic), appointment schedule (appointment order, appointment adjustment, add---ons to the schedule) and resource allocation. It was found that the best outcomes were obtained when not one but multiple changes were implemented simultaneously. Sepúlveda et al.6 studied the M. D. Anderson Cancer Centre Orlando, which is a cancer treatment facility and built a simulation model to analyse and improve flow process and increase capacity in the main facility. Different scenarios were considered like, transferring laboratory and pharmacy areas, adding an extra blood draw room and applying different scheduling techniques of patients. The study shows that by increasing the number of short---term (four hours or less) patients in the morning could increase chair utilisation. Discrete event simulation also helps improve a service where staff are ignorant about the behaviour of the system as a whole; which can also be described as a real professional system. Niranjon et al.7 used simulation successfully where they had to face such constraints and lack of accessible data. Carlos et al. 8 used Total quality management and simulation - animation to improve the quality of the emergency room. Simulation was used to cover the key point of the emergency room and animation was used to indicate the areas of opportunity required. This study revealed that a long waiting time, overload personnel and increasing withdrawal rate of patients are caused by the lack of capacity in the emergency room. Baesler et al.9 developed a methodology for a cancer treatment facility to find stochastically a global optimum point for the control variables. A simulation model generated the output using a goal programming framework for all the objectives involved in the analysis. Later a genetic algorithm was responsible for performing the search for an improved solution. The control variables that were considered in this research are number of treatment chairs, number of drawing blood nurses, laboratory personnel, and pharmacy personnel. Guo et al. 10 presented a simulation framework considering demand for appointment, patient flow logic, distribution of resources, scheduling rules followed by the scheduler. The objective of the study was to develop a scheduling rule which will ensure that 95% of all the appointment requests should be seen within one week after the request is made to increase the level of patient satisfaction and balance the schedule of each doctor to maintain a fine harmony between "busy clinic" and "quiet clinic". Huschka et al.11 studied a healthcare system which was about to change their facility layout. In this case a simulation model study helped them to design a new healthcare practice by evaluating the change in layout before implementation. Historical data like the arrival rate of the patients, number of patients visited each day, patient flow logic, was used to build the current system model. Later, different scenarios were designed which measured the changes in the current layout and performance. Wijewickrama et al.12 developed a simulation model to evaluate appointment schedule (AS) for second time consultations and patient appointment sequence (PSEQ) in a multi---facility system. Five different appointment rule (ARULE) were considered: i) Baily; ii) 3Baily; iii) Individual (Ind); iv) two patients at a time (2AtaTime); v) Variable Interval and (V---I) rule. PSEQ is based on type of patients: Appointment patients (APs) and new patients (NPs). The different PSEQ that were studied in this study were: i) first--- come first---serve; ii) appointment patient at the beginning of the clinic (APBEG); iii) new patient at the beginning of the clinic (NPBEG); iv) assigning appointed and new patients in an alternating manner (ALTER); v) assigning a new patient after every five---appointment patients. Also patient no show (0% and 5%) and patient punctuality (PUNCT) (on---time and 10 minutes early) were also considered. The study found that ALTER---Ind. and ALTER5---Ind. performed best on 0% NOSHOW, on---time PUNCT and 5% NOSHOW, on---time PUNCT situation to reduce WT and IT per patient. As NOSHOW created slack time for waiting patients, their WT tends to reduce while IT increases due to unexpected cancellation. Earliness increases congestion whichin turn increases waiting time. Ramis et al.13 conducted a study of a Medical Imaging Center (MIC) to build a simulation model which was used to improve the patient journey through an imaging centre by reducing the wait time and making better use of the resources. The simulation model also used a Graphic User Interface (GUI) to provide the parameters of the centre, such as arrival rates, distances, processing times, resources and schedule. The simulation was used to measure the waiting time of the patients in different case scenarios. The study found that assigning a common function to the resource personnel could improve the waiting time of the patients. The objective of this study is to develop an efficient scheduling template that maximises the number of served patients and minimises the average patient's waiting time at the given resources availability. To accomplish this objective, we will build a simulation model which mimics the working conditions of the clinic. Then we will suggest different scenarios of matching the arrival pattern of the patients with the availability of the resources. Full experiments will be performed to evaluate these scenarios. Hence, a simple and practical scheduling template will be built based on the indentified best scenario. The developed simulation model is described in section 2, which consists of a description of the treatment room, and a description of the types of patients and treatment durations. In section 3, different improvement scenarios are described and their analysis is presented in section 4. Section 5 illustrates a scheduling template based on one of the improvement scenarios. Finally, the conclusion and future direction of our work is exhibited in section 6. 2.

SIMULATION MODEL

A simulation model represents the actual system and assists in visualising and evaluating the performance of the system under different scenarios without interrupting the actual system. Building a proper simulation model of a system consists of the following steps. Observing the system to understand the flow of the entities, key players, availability of resources and overall generic framework.Collecting the data on the number and type of entities, time consumed by the entities at each step of their journey, and availability of resources.After building the simulation model it is necessary to confirm that the model is valid. (ABSTRACT TRUNCATED)

Pooled analyses of two international, multicenter clinical studies of romidepsin in 167 patients with cutaneous T-cell lymphoma (CTCL)

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Background: Romidepsin is a novel pan-HDAC inhibitor with demonstrated single-agent activity in 2 open-label clinical studies of 167 patients (pts) with CTCL [mycosis fungoides or Sézary Syndrome (SS)]. Data for these 2 studies were pooled for more accurate estimates of endpoints and investigation of subpopulations. Methods: GPI-04–0001 (pivotal study) enrolled 96 pts with confirmed CTCL who had recieved ≥1 prior systemic therapy. NCI 1312 (supportive study) enrolled 71 pts with CTCL. Pts recieved romidepsin, 14mg/m2 as a 4-hr infusion on days 1, 8, and 15 every 28 days until disease progression (≥25% increase). The primary efficacy endpoint for both studies was overall response rate (ORR) using a composite endpoint that included skin assessment, lymph node and visceral involvement and abnormal circulating T-cells/Sézary cells. Results: 167 pts received romidepsin (as-treated); 135 pts (81%) were in the efficacy evaluable population. Mean age was 57±12 yrs, 67% men, 87% white. 103 pts (76%) had stage ≥IIB disease. Median number of prior systemic therapies was 2 (range 1–8). ORR in the table. Responses were noted in: 42% of pts with stage ≥IIB; 11 (58%) of 19 pts with SS (erythroderma + Sézary cells, >1000/ml or >20% ); and 20 (38%) of 52 pts who received prior bexarotene and 8 (40%) of 20 pts who had received denileukin diftitox. Most common drug-related adverse events (AE), all grades, included: nausea (67%), fatigue (49%), anorexia (37%), ECG T-wave changes (29%), anemia (26%), dysgeusia (23%), neutropenia (22%), leucopenia (20%). Related serious AEs in 2% of pts: supraventicular arrhythmia, ventricular arrhythmia, infection, neutropenia, WBC decreased, hyperuricemia, hypotension; all other serious AEs in ≤1 pt. 3 deaths reported as possibly related. Conclusions: Romidepsin is a valuable new therapy for pts with CTCL based on the ORR, CR, durability of response, improvement in all disease compartments and responses at all stages and in all subpopulations analyzed.

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Systematic assessment of potential cardiac effects of the novel histone deacetylase (HDAC) inhibitor romidepsin

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Background: Romidepsin is a novel pan-HDAC inhibitor with single-agent activity in T-cell lymphoma. HDAC inhibitors reportedly have cardiovascular effects, in particular, QTc prolongation. To systematically and rigorously evaluate the potential cardiac effects of romidepsin, a cardiac safety monitoring plan was developed after discussions with the FDA. Methods: The effect of romidepsin on the change from baseline QTcF (Fridericia's correction) at key pharmacokinetic and pharmacodynamic (PD) time points was investigated. ECGs from 110 pts with advanced malignancies in 3 open-label, clinical studies of romidepsin 14 mg/m2 administered on days 1, 8 and 15 of a 28 day cycle were evaluated by blinded, independent assessors. Results: A mean 2.7 msec increase (90% confidence interval [CI]: 0.2, 5.3) in QTcF interval from a baseline post-antiemetic administration to after infusion of romidepsin was measured. A subanalysis of 74 patients (pts) evaluated QTcF from pre-antiemetic to post-romidepsin showed a mean change in QTcF of 5.0 msec (90% CI: 2.3, 7.7). Thus, antiemetic comedications likely accounts for a portion of the clinically apparent QTc effect. The QTc returned to baseline within 48 hrs. No absolute QTc values >480 msec and no QTc changes >60 msec were observed. No relationship was observed in an analysis of romidepsin plasma concentration versus QT changes. Mean heart rate (HR) increased 10.1±9.0 bpm after romidepsin administration, with a return to baseline by 24 hrs. Several treatment-emergent morphological changes in ECGs (including T wave and ST-segment) were reported. Many of the ECG morphologic abnormalities (determined by automated machine reading) were also observed at baseline. These ECG changes were transient and were not associated with functional cardiovascular changes or with symptoms. Conclusions: Romidepsin has a slight effect on the QT interval but rigorous ECG evaluation found this effect to be mild, below the threshold of regulatory and clinical concern, and not associated with any observed clinical cardiovascular events. Concentration response modeling found no PD relationship between romidepsin concentration and changes in QTcF, but did suggest a relationship between romidepsin concentration and HR.

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Candida albicans GRX2, encoding a putative glutaredoxin, is required for virulence in a murine model

Resistance of Candida albicans to reactive oxygen species is thought to enhance its virulence in mammalian hosts. Genes such as SOD1, which encodes the anti-oxidant, superoxide dismutase, are known virulence factors. We disrupted the gene GRX2, which encodes a putative glutathione reductase (glutaredoxin) in C. albicans, and we compared the mutant with an sod1Deltamutant. In vitro, the grx2Deltastrain, but not the sod1Delta strain, was defective in hypha formation. The grx2Deltastrain, but not sod1Delta, was significantly more susceptible to killing by neutrophils. When exposed to two compounds that generate reactive oxygen species, both mutants were susceptible to 1 mM menadione, but grx2Deltanull alone was resistant to diamide. Both mutants were attenuated in a murine intravenous challenge model, and a GRX2 reintegrant regained partial virulence. Emphasis on the putative function of products of genes such as SOD1 and GRX2 in resistance to oxidative stress may oversimplify their functions in the virulence process, since the grx2Deltastrain also gave defective hypha formation. Both mutants were sensitive to menadione and were slow to form germ tubes, though growth rates matched controls once the lag phase was passed.

Accuracy and usefulness of a clinical prediction rule and D-dimer testing in excluding deep vein thrombosis (DVT) in cancer patients

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Background: Cancer patients frequently present with thrombotic complications and rapid, accurate diagnostic testing would reduce morbidity and mortality. Although the combination of a low clinical probability using clinical prediction rules (e.g. Well’s Score) and a negative D-dimer result have proven to be safe and reliable in ruling out DVT in the general population, the accuracy of such a strategy is less certain in cancer patients. Because cancer patients often have alternative reasons for leg swelling and pain, and because malignancy and chemotherapy can render the D-dimer test positive in the absence of DVT, we hypothesize that the Well’s Score and D-dimer testing are potentially less accurate and less useful in excluding DVT in patients with active cancer. Methods: We performed a retrospective analysis of 2 prospective studies to compare the diagnostic test characteristics of the Well’s Score and D-dimer testing between patients with and without cancer presenting with suspected DVT. Results: A total of 1630 patients were studied; 107 had cancer. DVT was confirmed in 39.3% of patients with and 13.7% of patients without cancer. In both patient groups, the proportions of patients with DVT were significantly different among the high-, moderate- and low-probability groups according to the Well’s score (P<0.001). However, significantly fewer cancer patients (19.6%) had a low-probability score compared to patients without cancer (47.5%) (P<0.001). Similarly, 36.4% of cancer vs. 60.4% of noncancer patients had a negative D-dimer result (P<0.001). In cancer patients, a low probability score alone had a sensitivity of 95.2% (95%CI 82.6%-99.2%) and a specificity of 29.2% (95% CI 18.9%-42.0%). In combination with D-dimer testing, the sensitivity improved to 100% (95%CI 31.0%-100%) but the specificity was reduced to 26.4% (95%CI 13.5%-44.7%). In contrast, the specificity in patients without cancer was preserved at 53.9% (95%CI 50.4%-57.3%). Conclusion: DVT can be ruled out in cancer patients with a low clinical probability of DVT and a negative D-dimer result. However, the low specificity of these tests excludes very few patients and thereby limits their clinical usefulness.

No significant financial relationships to disclose.

Effect of an education programme on the utilization of a medical emergency team in a teaching hospital

BACKGROUND

Medical Emergency Teams (MET) have been developed to identify, review and manage acutely unwell ward patients. Previous studies have suggested that there may be obstacles to the utilization and activation of the MET.

AIMS

To determine the effect of a detailed education programme on the rate of utilization of the MET system 3.5 years after its introduction in a University teaching hospital.

METHODS

Prospective interventional study involving a detailed programme of education, feedback and decision support for nursing and medical staff given before, during and after implementation of a MET system. We measured the number of MET calls per month for both medical and surgical patients for 109 250 consecutive admissions to the acute care campus of Austin Health from August 2000 to June 2004.

RESULTS

Overall activation of the MET increased from 25 calls per month to a peak of 79 calls per month over the study period (average increase of one MET call/month). After standardization for monthly admissions, the increase in MET utilization for surgical patients (increase by 1.13 MET/1000 admissions/month) was 4.9-fold greater than for medical patients (increase by 0.23 MET/1000 admissions/month; P < 0.0001). At the peak level of activity (April 2004), the MET was called to review 8.4% of surgical and 2.7% of medical admissions (P < 0.0001).

CONCLUSIONS

There was a progressive increase in the utilization of the MET service in the 3.5 years after implementation, with the rate of uptake 4.9 times greater for surgical than for medical patients. Sustained uptake of the MET system is possible, but increased utilization may take several years to develop. Short-term studies testing the efficacy of the MET system are likely to significantly underestimate its effect on reducing adverse events. Intensive care unit resource adjustments will become necessary to meet increased demand.

Plasma glucose response to recreational diving in novice teenage divers with insulin-requiring diabetes mellitus

A growing number of individuals with insulin-requiring diabetes mellitus (IRDM) dive, but data on plasma glucose (PG) response to diving are limited, particularly for adolescents. We report on seven 16-17 year old novice divers with IRDM participating in a tropical diving camp who had recent at least moderate PG control (HbA1c 7.3 +/- 1.1%) (mean +/- SD). PG was measured at 60, 30 and 10 min pre-dive and immediately following 42 dives. Maximum depth (17 +/- 6 msw) and total underwater times (44 +/- 14 min) were not extreme. Pre-dive PG exceeded 16.7 mmol x L(-1) (300 mg x dL(-1)) in 22% of dives. Males had significantly higher pre-dive levels (15.4 +/- 5.6 mmol x L(-1) [277 +/- 100 mg x dL(-1)] vs. 12.8 +/- 2.9 mmol x L(-1) [230 +/- 52 mg x dL(-1)], respectively) and greater pre-post-dive changes (-4.3 +/- 4.4 mmol x L(-1) [-78 +/- 79 mg x dL(-1)] vs. -0.5 +/- 4.3 mmol x L(-1) [-9 +/- 77 mg x dL(-1)], respectively). Post-dive PG was < 4.4 mmol x L(-1) [< 80 mg x dL(-1)] in two dives by two different males (3.4 and 3.9 mmol x L(-1) [61 and 70 mg x dL(-1)]). No symptoms or complications of hypoglycemia were reported. These data show that in a closely monitored situation, and with benign diving conditions, some diabetic adolescents with good control and no secondary complications may be able to dive safely. The impact of purposeful elevation of PG to protect against hypoglycemia during diving remains to be determined.

A children's acute respiratory illness scale (CARIFS) predicted functional severity and family burden

OBJECTIVE

The Canadian Acute Respiratory Illness and Flu Scale (CARIFS) was developed to measure illness severity in children with acute respiratory infection. The objective of this study was to evaluate its performance in a European primary care setting.

STUDY DESIGN AND SETTING

178 children (median age 3 years) with cough and fever were recruited in UK general practice. Perceived severity of illness at recruitment was recorded by parents, doctors, and nurses. Parents also completed an illness diary, including the CARIF scale, until their child had recovered. In-depth interviews were conducted with 24 parents.

RESULTS

Parents found CARIFS relatively easy and quick to complete (78% of parents returned a fully completed diary covering the duration of the illness), internal consistency was high (minimum item correlation with total score 0.22; overall Cronbach's alpha statistic 0.85), and responsiveness to improvement in health was good (observed effect size of 0.45 at 8 h). At presentation, however, neither the overall CARIFS score nor the clinical element of the score correlated with physician assessment of clinical severity.

CONCLUSION

Of the three recognized domains of illness severity, CARIFS appears to be a good and valid measure of functional severity and burden of illness to the parent but it may not be a good measure of physiological severity.

Variability of the symptoms of chronic abacterial prostatitis/chronic pelvic pain syndrome during intermittent therapy with rectal prednisolone foam for ulcerative colitis

We describe the response of symptoms of chronic abacterial prostatitis/chronic pelvic pain syndrome (CAP/PPS) in a man treated with rectal prednisolone for concomitant ulcerative colitis. The temporal relationship of the symptoms of CAP/PPS to starting and stopping the topical corticosteroid over 2 treatment cycles lends further anecdotal support to our hypothesis that treatment of the immune-mediated response in this chronic condition has a beneficial effect upon symptomatic outcome.

A Phase I study of infusional vinblastine in combination with the P-glycoprotein antagonist PSC 833 (valspodar)

BACKGROUND

PSC 833 is a second-generation P-glycoprotein (Pgp) antagonist developed to reverse multidrug resistance (MDR). The authors conducted a Phase I study of orally administered PSC 833 in combination with vinblastine administered as a 5-day continuous infusion.

METHODS

Seventy-nine patients with advanced malignant disease were enrolled in the trial and treated with escalating doses of PSC 833. Pharmacokinetic interactions between PSC 833 and vinblastine were anticipated. Accordingly, when dose limiting toxicities were observed, the dose of vinblastine was reduced as PSC 833 was escalated. Three schedules and two formulations of PSC 833 were used in the study.

RESULTS

The maximum tolerated doses of PSC 833 were 12.5 mg/kg orally every 12 hours for 8 days for the liquid formulation in combination with 0.9 mg/m(2) per day vinblastine as a continuous intravenous infusion (CIV) for 5 days; and 4 mg/kg orally every 6 hours for 8 days for the microemulsion formulation in combination with 0.6 mg/m(2) per day vinblastine CIV for 5 days. The principal toxicities for PSC 833 were ataxia and paresthesias and for the combination, constipation, fever. and neutropenia. Increased oral bioavailability and increased peak and trough concentrations were observed with the microemulsion formulation. Significant interpatient variability in pharmacokinetic parameters was observed. Ten patients studied at the MTD for PSC 833 (4 mg/kg orally every 6 hours for 8 days) had inhibition of rhodamine efflux from CD56 positive peripheral lymphocytes as a surrogate for Pgp antagonism. Among 43 evaluable patients with clear cell carcinoma of the kidney, 3 patients had complete responses, and 1 patient had a partial response.

CONCLUSIONS

PSC 833 in combination with vinblastine can be administered safely to patients provided the vinblastine dose is adjusted for pharmacokinetic interactions. The high interpatient variability is a significant confounding factor. Surrogate studies with CD56 positive cells suggest that Pgp inhibition in the clinical setting is achievable. Improved methods for predicting pharmacokinetic interactions should improve future studies.

Characterisation of gene expression changes following permanent MCAO in the rat using subtractive hybridisation

Failure of several putative neuroprotectants in large multicentred clinical trials has re-focussed attention on the predictability of pre-clinical animal models of stroke. Model characterisation and relationship to heterogeneous patient sub-groups remains of paramount importance. Information gained from magnetic resonance imaging (MRI) signatures indicates that the Zea Longa model of rat middle cerebral artery occlusion may be more representative of slowly evolving infarcts. Understanding the molecular changes over several hours following cerebral ischaemia will allow detailed characterisation of the adaptive response to brain injury. Using a fully characterised model of Zea Longa middle cerebral artery occlusion we have used the representational difference analysis (RDA) subtractive hybridisation method to identify transcripts that accumulate in the ischaemic cortex. Along with a number of established ischaemia-induced gene products (including MCP-1, TIMP-1, hsp 70) we were also able to identify nine genes which have not previously been shown to accumulate following focal ischaemia (including SOCS-3, GADD45gamma, Xin).

Enhanced adenovirus transgene expression in malignant cells treated with the histone deacetylase inhibitor FR901228

The presence of coxsackie and adenovirus receptor (CAR) and alpha(v) integrin on cell surfaces is required for efficient adenovirus infection. Treatment of cells with the histone deacetylase inhibitor FR901228 (depsipeptide) increased CAR and alpha(v) integrin RNA levels in six cancer cell lines. Sodium butyrate and trichostatin A, other histone deacetylase inhibitors, caused similar increases. Cells treated with FR901228 prior to infection had a 4-10-fold increase in transgene expression from a beta-galactosidase-expressing adenoviral vector. These studies suggest that FR901228 increases the efficiency of adenoviral transgene expression and may be useful in cancer gene therapy.