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Average Waiting Time (average + waiting_time)
Selected AbstractsWaiting time for rehabilitation services for children with physical disabilitiesCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 5 2002D. Ehrmann Feldman Abstract Background Early rehabilitation may minimize disability and complications. However, children often wait a long time to gain admission to rehabilitation centres. Objectives To describe waiting times for paediatric physical and occupational therapy and to determine factors associated with these waiting times. Research Design The study was a prospective cohort design. Patients were followed from 1 January 1999 to 1 March 2000. Subjects All children with physical disabilities, aged 0,18 years, referred in 1999 from the Montreal Children's Hospital to paediatric rehabilitation centres. Measures Data on date of referral, date of first appointment at the rehabilitation centre, age, gender, diagnosis, region and language were obtained from the rehabilitation transfer database. Primary family caregivers of children who were transferred to a rehabilitation facility participated in a telephone interview regarding their perceptions of the transfer process. Results There were 172 children referred to rehabilitation facilities. The mean age of the children was 2.5 years. Average waiting time was 157.4 days (SD 57.1) for occupational therapy and 129.4 days (SD 51.6) for physical therapy. Decreased waiting time was associated with living in the city as opposed to the suburbs (hazard ratio = 1.77; 95% confidence interval = 0.92,3.41) and inversely associated with age (hazard ratio = 0.46; 95% confidence interval = 0.34,0.62). Among the 41 primary family caregivers who participated in the survey, higher empowerment scores were associated with shorter waits for rehabilitation. Conclusion Waiting time for rehabilitation services needs to be reduced. Empowered parents appear to manoeuvre within the system to reduce waiting times for their children. [source] Efficient and fair scheduling for two-level information broadcasting systemsCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 18 2008Byoung-Hoon Lee Abstract In a ubiquitous environment, there are many applications where a server disseminates information of common interest to pervasive clients and devices. For an example, an advertisement server sends information from a broadcast server to display devices. We propose an efficient information scheduling scheme for information broadcast systems to reduce average waiting time for information access while maintaining fairness between information items. Our scheme allocates information items adaptively according to relative popularity for each local server. Simulation results show that our scheme can reduce the waiting time up to 30% compared with the round robin scheme while maintaining cost-effective fairness. Copyright © 2008 John Wiley & Sons, Ltd. [source] PERSPECTIVE: MODELS OF SPECIATION: WHAT HAVE WE LEARNED IN 40 YEARS?EVOLUTION, Issue 10 2003Sergey Gavrilets Abstract Theoretical studies of speciation have been dominated by numerical simulations aiming to demonstrate that speciation in a certain scenario may occur. What is needed now is a shift in focus to identifying more general rules and patterns in the dynamics of speciation. The crucial step in achieving this goal is the development of simple and general dynamical models that can be studied not only numerically but analytically as well. I review some of the existing analytical results on speciation. I first show why the classical theories of speciation by peak shifts across adaptive valleys driven by random genetic drift run into trouble (and into what kind of trouble). Then I describe the Bateson-Dobzhansky-Muller (BDM) model of speciation that does not require overcoming selection. I describe exactly how the probability of speciation, the average waiting time to speciation, and the average duration of speciation depend on the mutation and migration rates, population size, and selection for local adaptation. The BDM model postulates a rather specific genetic architecture of reproductive isolation. I then show exactly why the genetic architecture required by the BDM model should be common in general. Next I consider the multilocus generalizations of the BDM model again concentrating on the qualitative characteristics of speciation such as the average waiting time to speciation and the average duration of speciation. Finally, I consider two models of sympatric speciation in which the conditions for sympatric speciation were found analytically. A number of important conclusions have emerged from analytical studies. Unless the population size is small and the adaptive valley is shallow, the waiting time to a stochastic transition between the adaptive peaks is extremely long. However, if transition does happen, it is very quick. Speciation can occur by mutation and random drift alone with no contribution from selection as different populations accumulate incompatible genes. The importance of mutations and drift in speciation is augmented by the general structure of adaptive landscapes. Speciation can be understood as the divergence along nearly neutral networks and holey adaptive landscapes (driven by mutation, drift, and selection for adaptation to a local biotic and/or abiotic environment) accompanied by the accumulation of reproductive isolation as a by-product. The waiting time to speciation driven by mutation and drift is typically very long. Selection for local adaptation (either acting directly on the loci underlying reproductive isolation via their pleiotropic effects or acting indirectly via establishing a genetic barrier to gene flow) can significantly decrease the waiting time to speciation. In the parapatric case the average actual duration of speciation is much shorter than the average waiting time to speciation. Speciation is expected to be triggered by changes in the environment. Once genetic changes underlying speciation start, they go to completion very rapidly. Sympatric speciation is possible if disruptive selection and/or assortativeness in mating are strong enough. Sympatric speciation is promoted if costs of being choosy are small (or absent) and if linkage between the loci experiencing disruptive selection and those controlling assortative mating is strong. [source] Class-based weighted fair queueing: validation and comparison by trace-driven simulationINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 10 2005Rachid El Abdouni Khayari Abstract World-wide web as well as proxy servers rely for their scheduling on services provided by the underlying operating system. In practice, this means that some form of first-come-first-served (FCFS) scheduling is utilized. Although FCFS is a reasonable scheduling strategy for job sequences that do not show much variance, for the world-wide web it has been shown that the requested-object sizes do exhibit heavy tails. Under these circumstances, job scheduling on the basis of shortest-job first (SJF) or shortest remaining processing time (SRPT) has been shown to minimize the total average waiting time. However, these methods have the disadvantage of potential job starvation. In order to avoid the problems of both FCFS and SJF we present in this paper a new scheduling approach called class-based interleaving weighted fair queueing (CI-WFQ). This scheduling approach exploits the specific characteristics of the job stream being served, that is, the distribution of the sizes of the objects being requested, to set its parameters such that good mean response times are obtained and starvation does not occur. In that sense, the new scheduling strategy can be made adaptive to the characteristics of the job stream being served. In this paper we compare the new scheduling approach (using trace-driven simulations) to FCFS, SJF and the recently introduced ,-scheduling, and show that CI-WFQ combines very good performance (as far as mean and variance of response time and blocking probability are concerned) with a scheduling complexity almost as low as for FCFS (and hence, lower than for SJF and ,-scheduling). The use of trace-driven simulation is essential, since the special properties of the arrival process makes analytical solutions very difficult to achieve. Copyright © 2005 John Wiley & Sons, Ltd. [source] Intervention program to reduce waiting time of a dermatological visit: Managed overbooking and service centralization as effective management toolsINTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 8 2007Yuval Bibi MD Background, Long waiting times are an impediment of dermatological patient care world-wide, resulting in significant disruption of clinical care and frustration among carers and patients. Objective, To reduce waiting times for dermatological appointments. Methods, A focus group including dermatologists and management personnel reviewed the scheduling process, mapped potential problems and proposed a comprehensive intervention program. The two major approaches taken in the intervention program were revision of the scheduling process by managed overbooking of patient appointments and centralization of the dermatological service into a centralized dermatological clinic. Results, Following the intervention program, the average waiting time for dermatological appointments decreased from 29.3 to 6.8 days. The number of scheduled appointments per 6 months rose from 17,007 to 20,433. Non-attendance proportion (no-show) decreased from 33% to 28%. Dermatologist work-hours were without significant change. Conclusions, Waiting lists for dermatological consultations were substantially shortened by managed overbooking of patient appointments and centralization of the service. [source] Modelling the development of supply-restricted telecommunications marketsJOURNAL OF FORECASTING, Issue 4 2001Towhidul Islam Abstract A large proportion of the world telecommunications market can be characterized as supply restricted. In ITU (1999) official waiting lists numbered about 50 million worldwide with an average waiting time of two years. More than 100 countries had not eliminated the waiting list for telephone connections and hence a supply restricted market prevailed in all of these countries. Only about 25 countries have succeeded in eradicating their waiting list for basic telephone service. In terms of the pattern of diffusion, the subscriber's flow from waiting applicants to adopters is controlled by supply restrictions adding an important dimension that needs to be addressed when modeling and forecasting demand. An empirical analysis of the diffusion of main telephones in 46 supply-restricted countries is presented to demonstrate the usefulness of a three-stage Bass model that has been proposed to capture the dynamics of supply restrictions. We also compare the forecasting ability of different approaches to estimation when panel data are available. Copyright © 2001 John Wiley & Sons, Ltd. [source] Tertiary paediatric obesity services in AustraliaJOURNAL OF PAEDIATRICS AND CHILD HEALTH, Issue 5 2008Pamela J Spilchak Aim: To examine the nature and availability of paediatric obesity services in tertiary care settings across the states/territories of Australia. Methods: Surveys were sent to all clinicians identified as offering obesity services to children and adolescents. Respondents were asked to identify other service providers in their area, who were also asked to complete the survey. Results: Sixteen clinicians responded to the survey, from 20 requests. The clinicians who responded identified nine services in three of the eight states/territories of Australia. Existing services are limited to children and adolescents with severe obesity, with an average of 12 new referrals per service each month and an average waiting time of 5 months for an appointment. Most services involve a multidisciplinary approach, although the mix of staff varies considerably and emphasises nutrition rather than physical activity approaches. Conclusions: Despite the public attention devoted to paediatric obesity, tertiary services in Australia are inadequate to meet the increasing incidence and prevalence of this complex condition. The development of tertiary services as part of service delivery arrangements for paediatric obesity and its associated morbidities must become a priority within the health system. [source] A componentwise index of service measurement in multi-component systemsNAVAL RESEARCH LOGISTICS: AN INTERNATIONAL JOURNAL, Issue 2 2003Sridhar Seshadri Abstract In this paper we present a componentwise delay measure for estimating and improving the expected delays experienced by customers in a multi-component inventory/assembly system. We show that this measure is easily computed. Further, in an environment where the performance of each of the item delays could be improved with investment, we present a solution that aims to minimize this measure and, in effect, minimizes the average waiting time experienced by customers. © 2002 Wiley Periodicals, Inc. Naval Research Logistics 50: 2003 [source] Underutilization of Hepatitis C-Positive Kidneys for Hepatitis C-Positive RecipientsAMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2010L. M. Kucirka Hepatitis C-positive (HCV(+)) candidates likely derive survival benefit from transplantation with HCV(+) kidneys, yet evidence remains inconclusive. We hypothesized that lack of good survival benefit data has led to wide practice variation. Our goal was to characterize national utilization of HCV(+) kidneys for HCV(+) recipients, and to quantify the risks/benefits of this practice. Of 93,825 deceased donors between 1995 and 2009, HCV(+) kidneys were 2.60-times more likely to be discarded (p < 0.001). However, of 6830 HCV(+) recipients, only 29% received HCV(+) kidneys. Patients over 60 relative rate (RR 0.86), women (RR 0.73) and highly sensitized patients (RR 0.42) were less likely to receive HCV(+) kidneys, while African Americans (RR 1.56), diabetics (RR 1.29) and those at centers with long waiting times (RR 1.19) were more likely to receive them. HCV(+) recipients of HCV(+) kidneys waited 310 days less than the average waiting time at their center, and 395 days less than their counterparts at the same center who waited for HCV(,) kidneys, likely offsetting the slightly higher patient (HR 1.29) and graft loss (HR 1.18) associated with HCV(+) kidneys. A better understanding of the risks and benefits of transplanting HCV(+) recipients with HCV(+) kidneys will hopefully improve utilization of these kidneys in an evidence-based manner. [source] Coordination of staffing and pricing decisions in a service firmAPPLIED STOCHASTIC MODELS IN BUSINESS AND INDUSTRY, Issue 4 2008an A. Serel Abstract Customer demand is sensitive to the price paid for the service in many service environments. Using queueing theory framework, we develop profit maximization models for jointly determining the price and the staffing level in a service company. The models include constraints on the average waiting time and the blocking probability. We show convexity of the single-variable subproblem under certain plausible assumptions on the demand and staffing cost functions. Using numerical examples, we investigate the sensitivity of the price and the staffing level to changes in the marginal service cost and the user-specified constraint on the congestion measure. Copyright © 2008 John Wiley & Sons, Ltd. [source] Delay analysis of a probabilistic priority disciplineEUROPEAN TRANSACTIONS ON TELECOMMUNICATIONS, Issue 6 2002Yuming Jiang In computer networks, the Strict Priority (SP) discipline is perhaps the most common and simplest method to schedule packets from different classes of applications, each with diverse performance requirements. With this discipline, however, packets at higher priority levels can starve packets at lower priority levels. To resolve this starvation problem, we propose to assign a parameter to each priority queue in the SP discipline. The assigned parameter determines the probability or extent by which its corresponding queue is served when the queue is polled by the server. We thus form a new packet service discipline, referred to as the Probabilistic Priority (PP) discipline. By properly adjusting the assigned parameters, not only is the performance of higher priority classes satisfied, but also the performance of lower priority classes can be improved. This paper analyzes the delay performance of the PP discipline. A decomposition approach is proposed for calculating the average waiting times and their bounds are studied. Two approximation approaches are proposed to estimate the waiting times. Simulation results that validate the numerical analysis are presented and examined. A numerical example which demonstrates the use of the PP discipline to achieve service differentiation is presented. This example also shows how the assigned parameters can be determined from the results of analysis mentioned above. [source] The effects of expanding patient choice of provider on waiting times: evidence from a policy experimentHEALTH ECONOMICS, Issue 2 2007Diane Dawson Abstract Long waiting times for inpatient treatment in the UK National Health Service have been a source of popular and political concern, and therefore a target for policy initiatives. In the London Patient Choice Project, patients at risk of breaching inpatient waiting time targets were offered the choice of an alternative hospital with a guaranteed shorter wait. This paper develops a simple theoretical model of the effect of greater patient choice on waiting times. It then uses a difference in difference econometric methodology to estimate the impact of the London choice project on ophthalmology waiting times. In line with the model predictions, the project led to shorter average waiting times in the London region and a convergence in waiting times amongst London hospitals. Copyright © 2006 John Wiley & Sons, Ltd. [source] Latest news and product developmentsPRESCRIBER, Issue 2 2008Article first published online: 11 FEB 200 NICE should evaluate all new medicines NICE should determine the cost effectiveness of all new medicines, the Health Select Committee has concluded in its second review of the Institute. The review, prompted by criticisms from patients, health professionals and the pharmaceutical industry, found that NICE is doing ,a vital job in difficult circumstances'. The Committee called for the costs to carers and society to be included in cost effectiveness estimates (this is currently prohibited) and for cost per QALY thresholds to be aligned with NHS affordability. NICE should publish brief appraisals at the time of a product launch , these could be used to negotiate prices. GPs responsible for unlicensed co-proxamol GPs who prescribe co-proxamol are now responsible for the consequences, the MHRA warns. The Agency agrees that the drug may be needed by ,a small group of patients who are likely to find it very difficult to change from co-proxamol or where alternatives appear not to be effective or suitable'. Following the withdrawal of product licences, stock that is currently in the supply chain may be dispensed but no new stock should be released by suppliers. The Drug Tariff price of co-proxamol has now increased from £2.79 to £20.36 per 100 tablets. Vitamin D deficiency on the increase Pregnant and breastfeeding women may need vitamin D supplements, the Department of Health has warned, and GPs are seeing increasing numbers of patients with vitamin D deficiency. Endogenous synthesis may be low in some ethnic groups and dark-skinned people, and north of Birmingham there is no light of the appropriate wavelength for the synthesis of vitamin D during the winter. The Department says free vitamin supplements are available for eligible patients through its Healthy Start Scheme (www.healthystart.nhs.uk) and may also be supplied at low cost by some PCTs. Innovation and good practice recognised Innovative practice and better outcomes for patients have been recognised through awards from the NHS Alliance and Improvement Foundation presented by the Secretary of State for Health, Rt Hon Alan Johnson, at the annual NHS Alliance conference held in Manchester. The Mountwood Surgery in Northwood, Middlesex, won the CHD QOF GP Practice Award sponsored by Schering Plough for their outstanding multidisciplinary approach to tackling CHD. In addition to having a highly organised in-house cardiology team, they have produced an interactive, patient-empowering booklet for CHD. Mountwood Surgery achieved blood pressure targets of 96.79 per cent in their CHD patients. North Tees PCT wins the CHD QOF PCO Award, also sponsored by Schering Plough, for their support and encouragement to GP practices to ,own' CHD care. They provide timely feedback of performance data using funnel plots and regular communication by the CHD LIT and Cardiac Network. Even though North Tees PCT has a high CHD prevalence, 4.2 per cent vs 3.6 per cent nationally, across the 27 practices 85 per cent of patients achieved cholesterol targets and 91 per cent reached the QOF blood pressure target. The St Benedict's Hospice Day Centre Project (for the Sunderland Teaching Primary Care Trust) won the Guy Rotherham Award for its excellent multidisciplinary team improvement of the palliative care provided. This team demonstrated a thorough understanding of the use of quality improvement methods to improve patient care, and carefully measured the individual improvements they made. Through the use of a referral ,decision tree', nonattenders were reduced by 300 per cent and average waiting times halved. The Extended Primary Care (EPC) Gynaecology Service (for the Practice Based Commissioning Consortium South Manchester Hub) was highly commended for its development of an effective and innovative service offering gynaecological treatment managed within a primary care setting, allowing patients improved access closer to home. The Salford Perinatal Mental Health Project was also highly commended for effectively challenging the high levels of maternal suicides. The awards were also supported by Prescriber, the British Cardiac Patients Association and the British Cardiac Society. Anastrozole superior to tamoxifen in long term A new analysis of the ATAC trial (Lancet Oncology 2008;9:45-53) shows that the advantages of the aromatase inhibitor anastrozole (Arimidex) over tamoxifen as adjuvant therapy for breast cancer persist for at least four years after the end of treatment. After primary treatment with surgery, chemotherapy or radiotherapy, postmenopausal women with localised invasive breast cancer were randomised to five years' treatment with anastrozole or tamoxifen. Among 5216 women who were hormone-receptor positive, anastrozole increased disease-free survival by 15 per cent after 100 months. Time to recurrence and distant recurrence were also increased, though overall survival was similar; the absolute difference in time to recurrence was greater at nine years (4.8 per cent) than at five years (2.8 per cent). Joint symptoms and fractures were more frequent with anastrozole during treatment but not thereafter. Use a steroid with a LABA , MHRA reminder The MHRA has reminded clinicians that patients treated with an inhaled long-acting beta-agonist (LABA) should also use an inhaled steroid. In the latest edition of Drug Safety Update (2008;1:No.6), the Agency reviews the implications of the SMART study (Chest 2006;129:15-26), which reported an increased risk of respiratory- and asthma-related deaths among patients using salmeterol (Serevent). This is contradicted by epidemiological data suggesting that asthma-related admissions have declined since LABAs were introduced. Randomised trials also do not support such a risk, probably because inhaled steroids are used more consistently in trial settings. The latest Update notes that product licences for carisoprodol (Carisoma) have been suspended due to concerns about the risk of abuse and psychomotor effects. It also includes a comprehensive summary of drug interactions with statins, a warning that methylene blue should not be prescribed for a patient taking a drug with serotonergic activity, and a reminder that only oral formulations of desmopressin are now licensed for primary nocturnal enuresis. This issue of Update is available at www.mhra.gov.uk. Copyright © 2008 Wiley Interface Ltd [source] | ||||||||||||||||