Different Measures Of Effectiveness Research Articles

Exploring the effects of Connected and Autonomous Vehicles on traffic safety and operation at full-cloverleaf interchanges

The effects of Connected and Autonomous Vehicles (CAVs) on interchanges such as full-cloverleaf interchanges have not yet been examined in prior studies. This study aims to explore the impacts of CAVs on traffic operation and safety at full-cloverleaf interchanges. It also assesses the influence of various Market Penetration Rates (MPRs) of CAVs on travel time, queues lengths, and conflict points considering various weaving lengths using VISSIM. The model calibration and validation were conducted considering different measures of effectiveness (throughput, speed, and travel time). The finding showed that higher MPRs of CAVs led to consistent travel time reductions across on-ramps, off-ramps, and weaving segments. Specifically, moving from the base scenario to 100% MPRs, travel times decreased by 46%, 41%, and 32% at the three interchanges under investigation, respectively. Additionally, safety evaluations utilizing the Surrogate Safety Assessment Model demonstrated considerable declines in the numbers of vehicle conflicts with increases in MPRs, averaging reductions of 20%, 32%, and 26% at the three interchanges from the base scenario to full MPRs, respectively. Also, it was found that increasing the weaving lengths enhanced traffic operation and safety. Overall, the findings highlight the promising benefits of integrating CAVs into the transportation system at full-cloverleaf interchanges.

Quantifying the impact of COVID-19 on essential health services: a comparison of interrupted time series analysis using Prophet and Poisson regression models.

Coronavirus disease 2019 (COVID-19) altered healthcare utilization patterns. However, there is a dearth of literature comparing methods for quantifying the extent to which the pandemic disrupted healthcare service provision in sub-Saharan African countries. To compare interrupted time series analysis using Prophet and Poisson regression models in evaluating the impact of COVID-19 on essential health services. We used reported data from Uganda's Health Management Information System from February 2018 to December 2020. We compared Prophet and Poisson models in evaluating the impact of COVID-19 on new clinic visits, diabetes clinic visits, and in-hospital deliveries between March 2020 to December 2020 and across the Central, Eastern, Northern, and Western regions of Uganda. The models generated similar estimates of the impact of COVID-19 in 10 of the 12 outcome-region pairs evaluated. Both models estimated declines in new clinic visits in the Central, Northern, and Western regions, and an increase in the Eastern Region. Both models estimated declines in diabetes clinic visits in the Central and Western regions, with no significant changes in the Eastern and Northern regions. For in-hospital deliveries, the models estimated a decline in the Western Region, no changes in the Central Region, and had different estimates in the Eastern and Northern regions. The Prophet and Poisson models are useful in quantifying the impact of interruptions on essential health services during pandemics but may result in different measures of effect. Rigor and multimethod triangulation are necessary to study the true effect of pandemics on essential health services.

Making global public policy work: A survey of international organization effectiveness

AbstractDo international organizations (IOs) actually help address global problems? This question is of major concern for global governance scholars and policy makers, yet few existing studies review issues of effectiveness across a range of different issue areas. This paper generates comparative insights on IO performance across seven policy domains, namely climate change, development, finance, investment, migration, security, and trade. Based on a detailed expert survey, we consider how key IOs in these issue areas perform across three different measures of effectiveness: constitutive effectiveness, compliance, and goal achievement. We also investigate causal claims on effectiveness, exploring how IO institutional design – and in particular measures of authority – influence their ability to shape policy outcomes. Taking stock of the distribution of authority across issue areas and policy functions, we ask whether highly formalized, deeply constraining institutional arrangements have a consistently stronger impact on state behaviour or whether less formalized institutions with fewer discretionary powers can also contribute to the effective implementation of internationally coordinated policies. Finally, we identify key cross‐cutting challenges for global governance effectiveness, including political conflict and politicization, concerns related to legitimacy and representation, and growing problem complexity.

Statistical methods for non-adherence in non-inferiority trials: useful and used? A systematic review

BackgroundIn non-inferiority trials with non-adherence to interventions (or non-compliance), intention-to-treat and per-protocol analyses are often performed; however, non-random non-adherence generally biases these estimates of efficacy.ObjectiveTo identify statistical methods that adjust...

Systematic review and meta-analysis of residential radon and lung cancer in never-smokers.

Globally, radon is the leading risk factor for lung cancer in never-smokers (LCINS). In this study, we systematically reviewed and meta-analysed the evidence of the risk of LCINS associated with residential radon exposure. Medline and Embase databases were searched using predefined inclusion and exclusion criteria to identify relevant studies published from 1 January 1990 to 5 March 2020 focused on never-smokers. We identified four pooled collaborative studies (incorporating data from 24 case-control studies), one case-control study and one cohort study for systematic review. Meta-analysis was performed on the results of the four pooled studies due to different measures of effect and outcome reported in the cohort study and insufficient information reported for the case-control study. In a post hoc analysis, the corresponding risk for ever-smokers was also examined. Risk estimates of lung cancer from residential radon exposure were pooled in the meta-analysis for 2341 never-smoker cases, 8967 never-smoker controls, 9937 ever-smoker cases and 12 463 ever-smoker controls. Adjusted excess relative risks (aERRs) per 100 Bq·m-3 of radon level were 0.15 (95% CI 0.06-0.25) for never-smokers and 0.09 (95% CI 0.03-0.16) for ever-smokers, and the difference between them was statistically insignificant (p=0.32). The aERR per 100 Bq·m-3was higher for men (0.46; 95% CI 0.15-0.76) than for women (0.09; 95% CI -0.02-0.20) among never-smokers (p=0.027). This study provided quantified risk estimates for lung cancer from residential radon exposure among both never-smokers and ever-smokers. Among never-smokers in radon-prone areas, men were at higher risk of lung cancer than women.

Performance Evaluation of Diverging Diamond Interchange Compared to Conventional Diamond Interchange: A Case Study in Riyadh City

The road users usually suffer from several kinds of congestion and delay especially at intersections. The traffic flow congestion due to increasing traffic volumes can be decreased by implementing some suitable alternative designs of interchanges such as Diverging diamond interchange (DDI) and conventional diamond interchange (CDI). In this study, a comparison between the DDI and CDI in traffic conditions in Riyadh city is conducted. The analysis involved different measures of effectiveness that includes delay, queue length, and number of stops. In this context, each interchange type was evaluated for traffic volumes at certain peak hours using micro-simulation program named as “Synchro.” The finding of this study shows that DDI provides a better result when compared with CDI in terms of delay, queue length and number of stops. The control delay for the DDI is approximately one third of the CDI. Also, the queue length for the DDI is about one half of the CDI. Furthermore, the number of stops for the DDI is as one half as the CDI.

Benefit–Cost Analyses of Rectangular Flashing Beacon Wrong-Way Driving Countermeasures on Toll Road Exit Ramps in Florida

In recent years, rectangular flashing beacons (RFBs) and other technologies have been used as wrong-way driving (WWD) countermeasures on limited access facilities. Studies have shown that these devices effectively reduce WWD, but no research has compared the financial benefits and costs of these countermeasures. Three different methodologies were used to conduct benefit–cost analyses for RFB WWD countermeasures installed on Central Florida toll road exit ramps. The studied benefits included savings from reductions in WWD crashes, non-crash events, and injuries, whereas costs included equipment, installation, and maintenance costs. For the first two methodologies, the reduction in WWD crash risk (WWCR) at the RFB-equipped ramps was determined. This WWCR considered non-crash WWD events, interchange design, and traffic volumes. Different measures of effectiveness (turn-around percentage of detected wrong-way vehicles at the RFB ramps and reduction in WWD 911 calls and citations at the RFB interchanges compared with similar comparison interchanges without RFBs) were used in these two methodologies to estimate the WWCR reduction and associated savings. For the third methodology, the relationship between WWD crashes and non-crash events was used to determine the average savings for WWD 911 calls and citations. Before–after analyses were then conducted to determine the individual reductions in WWD 911 calls and citations. Applying these three methods resulted in life-cycle benefit–cost ratios ranging from 2.49 to 4.10 (crash savings) and from 4.77 to 7.20 (injury savings). Other agencies could use these methodologies to determine the benefits of WWD countermeasures or other technologies with limited crash data.

Modelling horse management in the Australian Alps

SummaryManagement of the feral Horse (Equus caballus) in the Australian Alps bioregion is a difficult and emotive issue, with interested parties working from vastly differing perspectives. Compounding this, information regarding ecology and distribution of horses, and the cost and effectiveness of management strategies is often unknown or uncertain. Resolving these issues requires an objective approach with the flexibility to incorporate different potential scenarios. We used a spatially explicit population model to compare the potential effects of two different management strategies on populations of horses in the Australian Alps bioregion: culling from helicopters versus trapping and mustering. We populated the model using the results of population surveys conducted in 2014, vegetation data and cost estimates. We then provided an estimate of the effect of each strategy on population size across the Alps, and their corresponding costs, compared to no management. To account for uncertainties, we simulated different scenarios for horse population densities, dispersal rates and population growth rates. Management using aerial culling was more effective than mustering in every scenario modelled, and three to six times cheaper. Aerial culling was only slightly more effective within its control region. However, because mustering is necessarily restricted by road access, this translated to a substantial improvement in population control – up to 2000 horses where growth and dispersal rates were high. Our results unequivocally suggest aerial culling as the only strategy that could effectively control horses within the modelled range of scenarios; this result stands in addition to its other potential benefits of lower cost, animal stress and landscape disturbance. A major advantage of this modelling approach is that we can easily update it with new data, test different measures of effectiveness and add new scenarios to adapt to the rapidly changing situation on the ground, both in terms of the ecology and the political climate.

Comparative Evaluation of Cost – Effectiveness and Medication Adherence Between Olanzapine and Iloperidone in Patients of Psychosis

Background: To assess the cost – effectiveness between Iloperidone and Olanzapine in relation to different measures of effectiveness and to evaluate significance of medication adherence and costs and outcomes. Methods: A prospective, randomized, comparative, flexible dose clinical study of 1 year duration was conducted in 100 first episode (drug naive) cases of psychosis attending to psychiatric outdoor patient department of Rohilkhand Medical College and Hospital, Bareilly. 50 patients each in olanzapine (OLZ) and Iloperidone (ILO) group comprised the sample size. Patients were regularly evaluated by senior psychiatrist for dose titration. OLZ 10-20mg/day and ILO 6-12mg/day were used. Least expensive brands available in our hospital pharmacy were used. Cost – effectiveness and medication adherence were measured as per the formula. Results: It was observed that ILO (8mg/day) controlled 65-75% cases and 12mg/day dose controlled > 90% cases of psychosis. Whereas OLZ showed this level of control respectively with 10 – 15mg/day (average 12.5mg/day) and 15-20mg/day (average 17.5mg/d). Since olanzapine in 15-20mg/day dose cause more metabolic adverse events particularly obesity, hyperglycemia and dyslipidemia which need further management hence overall olanzapine is not cost-effective. 42(87.5%) cases had medication possession ratio (MPR) >90% in ILO group compared to 18 (37.5%) cases in OLZ group. Increased medication adherence led to better control and outcomes. Patients with 90% of patients on long term use.

Heterogeneous two-server queueing system with reverse balking and reneging

This paper presents an analysis of heterogeneous two-server queueing system with feedback, reverse balking, reneging and retention of reneged customers. The steady-state solution of the model is obtained and different measures of effectiveness are derived. Economic analysis of the model is performed studying the impact of balking probability and retention probability on the total expected profit of the system.

Performance Analysis of M/M(a,b)/1 Queuing Model with Balking and State-dependent Reneging and Service

The article investigates a M/M[Formula: see text]/1 queuing model with impatient customers. The size of a batch taken up for service depends on the number of customers present in the waiting line. The server serves a minimum of “ a” and a maximum of “ b” customers at a time. The service time is assumed to be exponentially distributed with mean dependent on the batch size. Customers arrive to the system as a Poisson process, and may leave on finding a long queue or may renege after waiting in the queue for an exponentially distributed time. The model is analyzed to find different measures of effectiveness of the system. A new measure of performance is also discussed. The approach adopted for analysis of the model is based on embedded Markov chain.

Matching Schemes and Public Goods: A Review

Matching schemes, where a party matches the contribution of others, reduce the effective price of a good and aim to foster its demand. We review the empirical literature on the effectiveness of these schemes in the context of public goods, especially in the field of charitable giving. As different measures of effectiveness are used, we classify results according to (i) the level of public good provision, (ii) the amount of individuals' contributions, (iii) the likelihood to give and (iv) the contribution conditional on contributing a positive amount. Generalizing results is challenging, since context specific factors matter. Predominantly, a match is found to create a significant increase in public good provision without crowding out individuals' contributions, while the effect on the likelihood of giving and contribution condition on contributing a positive amount is nonnegative. The discussion reveals several avenues for future research, as putting stronger emphasizes on long term effects, public good competition or heterogeneity in responses.

The effectiveness of payment for performance in health care: A meta-analysis and exploration of variation in outcomes

BackgroundPay for performance (P4P) incentive schemes are increasingly used world-wide to improve health system performance but results of evaluations vary considerably. A systematic analysis of this variation in the effects of P4P schemes is needed. MethodsEvaluations of P4P schemes from any country were identified by searching for and updating systematic reviews of P4P schemes in health care in four bibliographic databases. Outcomes using different measures of effect were converted into standardized effect sizes (standardized mean difference, SMD) and each study was categorized as to whether or not it found a positive effect. Subgroup analysis, meta-regression and multilevel logistic regression were used to investigate factors explaining heterogeneity. Random-effects models were used because they take into account heterogeneity likely to be due to differences between studies rather than just chance. Sensitivity analysis was used to test the effect of different assumptions. Findings96 primary studies were identified; 37 were included in the meta-analysis and meta-regression and all 96 in the logistic regression. The proportion of observed variation in study results that can be explained by true heterogeneity (I2) was 99.9%. Estimates of effect of P4P schemes were lower in evaluations using randomized controlled trials (SMD=0.08; 95% CI: 0.01–0.15) compared to no controls (0.15; 95% CI: 0.09–0.21), and lower for those measuring outcomes (e.g., smoking cessation) (SMD=0.0; 95% CI: −0.01 to 0.01) compared to process measures (e.g., giving cessation advice) (0.18; 95% CI: 0.06–0.31).Adjusting for other design features and the evaluation method, the odds of showing a positive effect was three times higher for schemes with larger incentives (>5% of salary/usual budget) (OR=3.38; 95% CI: 1.07–10.64). There were non-statistically significant increases in the odds of success if the incentive is paid to individuals (as opposed to groups) (OR=2.0; 95% CI: 0.62–6.56) and if there is a lower perceived risk of not earning the incentive (OR=2.9; 95% CI: 0.78–10.83). Schemes evaluated using less rigorous designs were 24 times more likely to have positive estimates of effect than those using randomized controlled trials (OR=24; 95% CI: 6.3–92.8). InterpretationEstimates of the effectiveness of incentive schemes on health outcomes are probably inflated due to poorly designed evaluations and a focus on process measures rather than health outcomes. Larger incentives and reducing the perceived risk of non-payment may increase the effect of these schemes on provider behavior.

Economic analysis of an M / M / c / N queuing model with balking, reneging and retention of reneged customers

In this paper, we study a finite capacity, multi-server Markovian queuing model with balking and reneging in which the probability of retaining the reneged customers is incorporated. This concept of retaining the reneged (impatient) customers has a great significance in revenue generating queuing systems. The queuing model developed in this paper is a new advancement in the fundamental queuing models dealing with balking and reneging. The transient and steady-state solutions of the model are obtained and different measures of effectiveness are derived. It is found that the average number of customers in the system increases as the probability of retaining the reneged customers (say, q) increases. Economic analysis of the model is also performed to study the effect of the probability of retaining the reneged customers on total expected profit of the system. Some important queuing models are obtained as particular cases of this model.

Economic analysis of M/M/c/N queue with retention of impatient customers

This paper investigates a finite capacity multi-server Markovian queuing model with customer impatience in which the probability of retaining the impatient customers is incorporated. This concept of retaining the impatient customers has a great significance in revenue generating queuing systems. The queuing model developed in this paper is a new advancement in the fundamental queuing models dealing with reneging (customer impatience). The steady-state solution of the model has been obtained and different measures of effectiveness have been computed. It has been found that the expected number of customers in the system increases as the probability of retaining the impatient customers (say, q) increases. The economic aspects of the model have also been discussed. It has been observed that the total expected profit of the system increases steadily with the increase in the probability of retaining the impatient customers. Such analysis may help decision makers decide about the formulation of different customer retention strategies by knowing costs and profits associated with them.

An M/M/c/N queuing system with reneging and retention of reneged customers

The customer impatience due to reneging results into loss of potential customers. But, if we have certain mechanism to retain such impatient customers, a significant amount of revenue can be increased. In this paper, we have developed a Markovian, finite capacity, multi-server queuing system which deals with retention of reneged customers. Accordingly, a reneged customer can be made (convinced) to stay in the queuing system for his further service with some probability, say q and he may abandon the queue without receiving the service with probability p (= 1 – q). The steady-state solution of the model has been derived. The different measures of effectiveness of the queuing model have been obtained. The effect of probability of customer retention on the expected system size has been studied. A comparative analysis of some queuing models has been carried out to see the impact of customer retention on the expected system size. Some queuing models have been derived as particular cases of this model.

Effectiveness of biodiversity surrogates for conservation planning: different measures of effectiveness generate a kaleidoscope of variation.

Conservation planners represent many aspects of biodiversity by using surrogates with spatial distributions readily observed or quantified, but tests of their effectiveness have produced varied and conflicting results. We identified four factors likely to have a strong influence on the apparent effectiveness of surrogates: (1) the choice of surrogate; (2) differences among study regions, which might be large and unquantified (3) the test method, that is, how effectiveness is quantified, and (4) the test features that the surrogates are intended to represent. Analysis of an unusually rich dataset enabled us, for the first time, to disentangle these factors and to compare their individual and interacting influences. Using two data-rich regions, we estimated effectiveness using five alternative methods: two forms of incidental representation, two forms of species accumulation index and irreplaceability correlation, to assess the performance of ‘forest ecosystems’ and ‘environmental units’ as surrogates for six groups of threatened species—the test features—mammals, birds, reptiles, frogs, plants and all of these combined. Four methods tested the effectiveness of the surrogates by selecting areas for conservation of the surrogates then estimating how effective those areas were at representing test features. One method measured the spatial match between conservation priorities for surrogates and test features. For methods that selected conservation areas, we measured effectiveness using two analytical approaches: (1) when representation targets for the surrogates were achieved (incidental representation), or (2) progressively as areas were selected (species accumulation index). We estimated the spatial correlation of conservation priorities using an index known as summed irreplaceability. In general, the effectiveness of surrogates for our taxa (mostly threatened species) was low, although environmental units tended to be more effective than forest ecosystems. The surrogates were most effective for plants and mammals and least effective for frogs and reptiles. The five testing methods differed in their rankings of effectiveness of the two surrogates in relation to different groups of test features. There were differences between study areas in terms of the effectiveness of surrogates for different test feature groups. Overall, the effectiveness of the surrogates was sensitive to all four factors. This indicates the need for caution in generalizing surrogacy tests.

Effectiveness analysis of a system with a special warranty scheme

This paper analyses a two-dissimilar-unit priority redundant system under the cover of a special warranty scheme. The first unit is a priority unit in operation and fails in three modes, namely minor, marginal and catastrophic. The cold standby unit fails in a single mode. The warranty scheme provides replacement cover for the priority unit for catastrophic failure and repair cover for other failure types. It also provides repair cover for the non-priority unit (standby unit) for failure. A single repair/replacement facility is available to cater to the needs of the system. Using regenerative point technique in Markov renewal process we find different measures of effectiveness and the expected profit incurred in ( 0 , t ] .

Differentiated Analysis of Level of Service F within the German Highway Capacity Manual

In the American as well as the German Highway Capacity Manual, the quality of service that is determined by different measures of effectiveness can be described by six levels of service. While there are five levels (A to E) to distinguish undersaturated flow conditions, only one level of service (LOS) describes congestion. A differentiation of oversaturated traffic flow conditions (LOS F) is not possible so far. As traffic networks have become more and more congested this is insufficient, and instruments are needed to identify the worst bottlenecks. The paper presents approaches for a division of LOS F into differentiated sublevels of saturated flow (F1 to F4) and proposes corresponding calculation methods. Different traffic flow models and queuing equations are considered for the estimation of travel times as a function of traffic demand. Four potential methods for standardization are discussed that differ in the performance measures used. They are described by using freeway sections as an example, but they can be applied for all types of road facilities. The methods are analyzed and compared in terms of their significance, their sensitivity, and the availability of input data. On that basis, a 24-h analysis of traffic performance is recommended for implementation within the guidelines because it is able to evaluate congestion in a multidimensional way. The evaluation methods developed within this research can be used to assess the quality of service on existing congested facilities depending on traffic demand. They can help decision making and ensure that funds are spent efficiently.

Evaluation of Effectiveness of School Zone Flashers in North Carolina

The North Carolina Department of Transportation has been placing flashing beacons on school zone signs where warranted in an attempt to provide more awareness of the school zone speed limit and at the request of schools. The purpose of this project was to evaluate the effectiveness of placing flashing beacons on school zone speed limit signs and to determine if speed compliance was improved in school zones. A sample set of 15 treatment school zones with flashers and 15 comparison school zones without flashers was selected for analysis throughout North Carolina. Sites were selected to include a mix of geometric features and geographic elements. Flashers had been installed at each of the sites for at least 3 years. The school-time speed limits at all sites ranged between 25 and 45 mph. Speed data were collected at all sites during the reduced-speed school zone hours of operation (school time) and outside the reduced-speed school zone hours of operation (nonschool time). Several different measures of effectiveness were calculated to compare the characteristics of the speed distributions, including the percentage of vehicles exceeding the speed limit, average speed, 85th percentile speed, and pace speed. Results showed no practical difference in vehicle speeds between the flasher and nonflasher locations during school-time hours. Although vehicle speeds did decrease from nonschool-time hours to school-time hours at both flasher and nonflasher sites, the speed reductions were not enough to bring drivers into compliance with the school-time speed limit. Both locations with and without flashers had an extremely low compliance rate with the school-time speed limit.