Microsimulation Method Research Articles

Projecting the clinical burden of chronic kidney disease at the patient level (Inside CKD): a microsimulation modelling study

Chronic kidney disease (CKD) is a global concern that presents significant challenges for disease management. Several factors drive CKD prevalence, including primary risk factors, such as type 2 diabetes and hypertension, and an ageing population. Inside CKD is an international initiative that aims to raise awareness of the substantial burden incurred by CKD. Using a peer-reviewed microsimulation method, the clinical burden of CKD was estimated from 2022 to 2027. Demographic data from the Americas, Europe, and Asia-Pacific/Middle East were used to generate virtual populations and to project the prevalence of CKD, kidney replacement therapy, associated cardiovascular complications, comorbid conditions, and all-cause mortality in the CKD population over the modelled time frame. Across the 31 participating countries/regions, the total prevalence of CKD was projected to rise to 436.6 million cases by 2027 (an increase of 5.8% from 2022), with most cases (∼80%) undiagnosed. Inside CKD projected a mean of 8859 cases of heart failure, 10,244 of myocardial infarction, and 7797 of stroke per 100,000 patients with CKD by2027. The clinical impact of CKD is substantial and likely to increase; the high prevalence of undiagnosed cases and associated complications may benefit from the implementation of health policy interventions that promote screening, earlier diagnosis, and interventions to improve outcomes. AstraZeneca.

Influences of specialty identity when implementing a new emergency department in Denmark: a qualitative study

BackgroundThe Danish Health Authority recommended the implementation of new types of emergency departments. Organizational changes in the hospital sector challenged the role, identity, and autonomy of medical specialists. They tend to identify with their specialty, which can challenge successful implementation of change. However, investigations on specialty identity are rare in implementation science, and how the co-existence of different specialty identities influences the implementation of new emergency departments needs to be explored for the development of tailored implementation strategies. The aim of this study was to examine how medical specialty identity influences collaboration between physicians when implementing a new emergency department in Denmark.MethodsQualitative methods in the form of participants’ observations at 13 oilcloth sessions (a micro-simulation method) were conducted followed up by 53 individual semi-structured interviews with participants from the oilcloth sessions. Out of the 53 interviews, 26 were conducted with specialists. Data from their interviews are included in this study. Data were analysed deductively inspired by Social Identity Theory.ResultsThe analysis yielded three overarching themes: [1] ongoing creation and re-creation of specialty identity through boundary drawing; [2] social categorization and power relations; and [3] the patient as a boundary object.ConclusionsSpecialty identity is an important determinant of collaboration among physicians when implementing a new emergency department. Specialty identity involves social categorization, which entails ongoing creation and re-creation of boundary drawing and exercising of power among the physicians. In some situations, the patient became a positive boundary object, increasing the possibility for a successful collaboration and supporting successful implementation, but direct expressions of boundaries and mistrust were evident. Both were manifested through a dominating power expressed through social categorization in the form of in- and out-groups and in an “us and them” discourse, which created distance and separation among physicians from different specialties. This distancing and separation became a barrier to the implementation of the new emergency department.

Profitability Optimization of Dairy Farms: The Effect of Pregnancy Rate and Culling Decision.

One of the most important decisions in dairy cattle production today is the correct choice of culling time for cows. In the culling decision process, the farmer has to take into account a number of factors, the complexity of which makes the decision-making task difficult. A crucial factor is the evolution of reproductive indicators. The aim of the research was to develop a microsimulation method that can be used to easily investigate the impact on profitability of increasing pregnancy rates and when the culling decision is made. In the microsimulation, the stock was examined without changing any other conditions. A microsimulation method has been developed to determine with high accuracy the effect of the pregnancy rate and the increase in culling days on the economic indicators of individual dairy farms. By microsimulation, the effect of changing these two parameters on the expected milk production of cows, the most important economic indicator for cattle farms, was investigated. The other parameters of economic importance were simulated using a cattle farm database. The purpose of microsimulation is to assist in producing certain managerial decisions in order to achieve better profitability and economic efficiency. In summary, the results showed that increasing the pregnancy rate can successfully reduce the length of the calving interval, but the improved pregnancy rate did not show a significant increase in milk production. In order to obtain results that can be used by farms, the authors intend to further develop the model in the future, adapting it to farms and taking into account their specificities.

Türkiye için Demografik Mikrosimülasyon Modeli

This paper focuses on the use of microsimulation methodology to generate reliable population estimations for Türkiye. Microsimulation closely mimics life course dynamics and is therefore well-suited for predicting demographic changes. Using data from the 2018 Türkiye Demographic Health Survey, we developed a new microsimulation method that allows for greater customization and accuracy without relying on external patterns or models. The resulting population simulation includes age, education, marital status, usual residence, and labour force status for each individual until 2030. Our study demonstrates the flexibility and adaptability of microsimulation for demography and argues that it provides a coherent and meaningful way to estimate and project population attributes that other tools cannot provide. Ultimately, the dynamic simulation model has the potential to inform important policy decisions related to the population in Türkiye.

Personalized medicine comes to a blood center near you

Personalized medicine comes to a blood center near you

Dry port integrated port development with microsimulation method for solving port-city conflict: a case of Alsancak Port

Dry port integrated port development with microsimulation method for solving port-city conflict: a case of Alsancak Port

Estimating the population exposed to a risk factor over a time window: A microsimulation modelling approach from the WHO/ILO Joint Estimates of the Work-related Burden of Disease and Injury.

Burden of disease estimation commonly requires estimates of the population exposed to a risk factor over a time window (yeart to yeart+n). We present a microsimulation modelling approach for producing such estimates and apply it to calculate the population exposed to long working hours for one country (Italy). We developed a three-model approach: Model 1, a multilevel model, estimates exposure to the risk factor at the first year of the time window (yeart). Model 2, a regression model, estimates transition probabilities between exposure categories during the time window (yeart to yeart+n). Model 3, a microsimulation model, estimates the exposed population over the time window, using the Monte Carlo method. The microsimulation is carried out in three steps: (a) a representative synthetic population is initiated in the first year of the time window using prevalence estimates from Model 1, (b) the exposed population is simulated over the time window using the transition probabilities from Model 2; and (c) the population is censored for deaths during the time window. We estimated the population exposed to long working hours (i.e. 41-48, 49-54 and ≥55 hours/week) over a 10-year time window (2002-11) in Italy. We populated all three models with official data from Labour Force Surveys, United Nations population estimates and World Health Organization life tables. Estimates were produced of populations exposed over the time window, disaggregated by sex and 5-year age group. Our modelling approach for estimating the population exposed to a risk factor over a time window is simple, versatile, and flexible. It however requires longitudinal exposure data and Model 3 (the microsimulation model) is stochastic. The approach can improve accuracy and transparency in exposure and burden of disease estimations. To improve the approach, a logical next step is changing Model 3 to a deterministic microsimulation method, such as modelling of microflows.

Traffic Signalizing Application at Unsignalized Intersection Applying Vissim Software Microsimulation

An intersection is a meeting point of several road sections that have potential traffic conflicts. Each of these may become the intersection of opposite traffic flows. Therefore, it is critical to have the best traffic control to avoid potential collisions among vehicles. Simpang Jembatan 5 Kalimalang is an unsignalized-intersection with four legs—one of which is a bridge. The absence of traffic control in the intersection may lead to many traffic conflicts. This study aims to determine the best traffic control to increase safety in Simpang Jembatan 5 Kalimalang. It was a case study with a micro-simulation method of analysis. The data were analyzed using VISSIM and SSAM. VISSIM was used to analyze the performance of the existing intersection condition in Simpang Jembatan 5 and to analyze the counter condition for the recommendation. Meanwhile, SSAM was employed to analyze traffic conflict in the intersection. The result of the study revealed that the alternative counter condition of the intersection in terms of replenishment of two-phased-APPIL with 106 seconds of cycle time was effective in reducing 24% of traffic conflict; in addition, the delay value was 12.4 indicating that the intersection service level was down to B level. The reduction of traffic conflict and intersection service implied that the safety level in Simpang Jembatan 5 Kalimalang increased.

Use of a microsimulation method for assessing dynamics of smoking status and gains in life expectancy after quitting in a longitudinal cohort of US older adults

ObjectivesPrevious studies were unable to estimate the dynamics of smoking status in the US elderly general population, and no study has assessed the benefit of quitting in terms of resultant...

Exploring the discharge characteristics of personal care behaviors for high precision estimation of microplastic emission

Microplastics (MPs) from personal care and cosmetic products (PCCPs) pose a threat to aquatic environment due to the small size and the complexity of composition. Although the habits of personal care behaviors (PCBs) vary from individuals affecting MPs emissions, quantitative research is not sufficient to support high-precision emission estimates and targeted management decisions. Based on a questionnaire survey about PCBs and laboratory experiments on corresponding PCCPs utilization, this study proposed a bottom-up micro-simulation method to quantify MPs emissions combining multinomial logit model and categorized emission coefficients, and identified the impact of individual attributes on the emissions. The results show that the annual PCBs-derived MPs emissions amounted to 2931.8 trillion particles in China, of which teeth brushing, face washing, and bathing behavior accounted for 29%, 36% and 35%, respectively. The residents discharged an average of 2.18 million particles per capita per year with 95% confidence interval of 0.58–4.34 million particles. Gender, age and living region had greater impacts on PCBs-derived MPs emissions. The effect of living region was significantly related to local temperature and humidity. The estimation based on the MPs discharge characteristics of PCBs provides high-precision method regarding the MPs emission from people's daily life and contributes to further understanding the source of MPs and initiating environmental control strategies.

Dry Port Integrated Port Development with Microsimulation Method for Solving Port-City Conflict: A Case of Alsancak Port

Dry Port Integrated Port Development with Microsimulation Method for Solving Port-City Conflict: A Case of Alsancak Port

Obtaining mass normalized mode shapes of motorway bridges based on the effect of traffic movement

Ambient vibration testing has become a promising alternative for the forced vibration method due to its well-established practical advantages on bridge structures. However, because of the unavailability of the input data in output-only vibration tests, the extracted mode shapes are not mass normalized. Mass normalized mode shapes are essential in various modal analysis applications such as flexibility-based damage detection techniques. Mass change method was proposed to resolve this issue for Operational Modal Analysis (OMA); however, there are certain practical issues that limit the applicability of this method to real-world structures. In this paper, we propose to utilize the dynamic effects of the traffic movement over bridges as the required perturbation to the structure's modal properties. Numerous traffic conditions are considered, and uncertainty analyses are performed to evaluate the suitability of the loads in different traffic scenarios. Furthermore, a numerical case study is conducted on Hafez Bridge in the city of Tehran, Iran. Actual traffic conditions are simulated using the traffic micro-simulation method, and vehicle forces and masses are applied to the finite element model of the bridge using the equivalent nodal forces method. OMA is conducted in the time domain, and modal parameters are extracted using the Stochastic Subspace Identification method. Finally, it is shown that using the proposed framework, not only the modal scaling factors are estimated with satisfying accuracy, but also the practical difficulties of the conventional mass change method such as bridge shutdowns are eliminated.

Current Development in Microsimulation and Experimental Innovation method in JUTTA Model

Nowadays, microsimulation method has been introduced to different fields, such as Social Science, Medicine research and Economic study. This method evaluates the effects of the proposed interventions or policies before they are implemented in the real world. In this article, we will concentrate on microsimulation method used in Social Science by firstly explaining two main streams in microsimulation world, Static approach and Dynamic approach. In the following section, the uncertainty of a Finnish static microsimulation model JUTTA is assessed and Toimtuki model, one of the sub-models in JUTTA is detected to have space to be more accurate. In order to do so, two experimental statistical models-Linear Regression model and Two-Stage Least Squares(2SLS) model are applied to it. From the results, we could conclude that both the Linear Regression and 2SLS successfully improves the accuracy of TOIMTUKI to some extent.

Unobserved Population Heterogeneity and Dynamics of Health Disparities.

A growing body of literature has reported widening educational health disparities across birth cohorts or time periods in the United States, but has paid little attention to the implication of mortality selection on the cohort trend in health disparities. This study investigates how changes in the variance of unobserved frailty over time may complicate the interpretation of cohort trends in health disparities and life expectancy. We use the microsimulation method to test the effect of mortality selection and further propose a counterfactual simulation procedure to estimate its contribution. Data used in the simulations are based on Panel Studies of Income Dynamics 1968-2013, National Health and Nutrition Examination Survey data 1999-2012, and National Health Interview Survey data 1986-2011. Simulation shows that mortality selection may generate seemingly contradictory trends in health disparities and life expectancy across birth cohorts at the group and individual level. Life expectancy can change even when individual mortality curve is fixed. In the absence of a change in the causal effect of education on mortality at the individual level, an educational life expectancy gap can change across cohorts as a result of the change in frailty variance. Empirical analysis shows that mortality selection accounts for a sizeable amount of contribution to the widening educational life expectancy gap from the 1950s to 1960s birth cohorts in the United States. We demonstrate mortality selection can complicate the cohort trend in health disparities and life expectancy and propose a counterfactual simulation method to evaluate its contribution.

Multi-scale fatigue damage prognosis for long-span steel bridges under vehicle loading

Fatigue damage prognosis for long-span steel bridges is of the utmost importance in bridge maintenance and management. In this study, a multi-scale fatigue damage prognosis algorithm is developed to calculate the trans-scale fatigue damage accumulation of newly-built long-span steel bridges under vehicle loading. The necessity and procedure of establishing a multi-scale finite element (FE) model of a newly-built long-span bridge for fatigue damage prognosis are first introduced. The future vehicle loading on the bridge is forecasted using the recorded weigh-in-motion (WIM) data and the agent-based traffic flow micro-simulation method. Then, the multi-scale fatigue damage prognosis algorithm is developed based on the multi-scale FE model and using the future vehicle loading. Finally, the proposed algorithm is applied to a newly-built long-span cable-stayed bridge for the time period from 2010 to 2020. The results show that the macro-scale fatigue damage accumulation and micro-scale short crack evolution of the critical components of the bridge can be simultaneously predicted and visualized. The proposed algorithm can be used as a numerical tool for fatigue damage prognosis of steel bridges where (or near where) WIM station is installed.

Deflection analysis of long-span girder bridges under vehicle bridge interaction using cellular automaton based traffic microsimulation.

Deflection is a crucial indicator to reflect the operating condition of girder bridges, which can be used to evaluate structure condition and identify abnormal loading. The paper analyzed the deflection characteristics of long-span girder bridges based on the coupling vibration between stochastic traffic stream and bridge. First, the latest research advances were integrated to form an analytical model of the coupling vibration between stochastic traffic stream and bridge. Then, a generalized Pareto distribution model based on peaks-over-threshold theory was established to predict the extreme girder deflection. Next, a cellular automaton based microsimulation method was proposed to model the traffic loads on bridges, which utilized the intelligent driver car-following model and acceptance distance based lane-changing model. Finally, these theories were applied in the case study of a long-span prestressed concrete continuous girder bridge. It is discovered from the study that, under the coupling vibration between stochastic traffic stream and bridge, the predicted extreme deflection of the case bridge is far lower than the specified design value. Hence, a grading warning model was established and employed to the analysis of deflection monitoring data of the bridge, showing a wide potential prospect of application.

A simulation study of the role of cohort forces in mortality patterns

ABSTRACTThis study uses the micro-simulation method to investigate the role of cohort forces in age-dependent mortality pattern. We test the micro mechanisms for cohort evolution and mortality selection, and how these two biological and demographic forces may interact with epidemiologic transition to shape the cohort age-dependence of mortality pattern in both early- and later-transition countries. We show that cohort evolution is due to the declining rate of mortality acceleration at the individual level, which is associated with lower initial mortality rates but not smaller variance of frailty distribution in later birth cohorts. The steeper slope of mortality acceleration at the population level among later birth cohorts is due to mortality selection mechanism associated with smaller variance of frailty distribution but not lower initial mortality rates. These two forces jointly shape the non-crossover cohort age-dependence of mortality pattern regardless of the differential mechanisms of epidemiologic transition in early- and later-transition countries.

Estimating the economic effects of pharmaceutical reimbursement scheme reform by microsimulation

Estimating the effects of reforms in advance is an important part of evidence-based and transparent legislative processes. The aim of this study was to describe a microsimulation method created to produce ex ante estimates of pharmaceutical pricing and reimbursement policy reforms. As a case example, the estimates for the 2016 pharmaceutical reimbursement scheme reform, including, e.g., the introduction of a €50 annual deductible, are presented. A static microsimulation model was developed based on the reimbursed purchases of 380,931 individuals drawn at random (10% sample) from the prescription register. The 2016 reform was projected to create savings of €44 million/year for the National Health Insurance (NHI). For patients, the median annual out-of-pocket costs increased from €78 to €96 (by +€18). For 97%, the estimated change was less than €50/year. The majority of patients whose out-of-pocket costs increased had relatively low prior costs. However, >€50/year increases predominantly affected patients entitled to higher reimbursements based on chronic or severe illnesses, among whom older and lower-income individuals were overrepresented. Increases of >€100 were rare (0.003%) and derived from exceptional circumstances. The microsimulation produced prompt but versatile estimates of the effects of legislative reforms by factoring in the entire spectrum of individual situations among affected patients.

Distributional Impacts of Behavioral Effects –Ex-Ante Evaluation of the 2017 Unemployment Insurance Reform in Finland

In 2017, the potential duration of the Finnish earnings-related unemployment benefit was cut from 500 to 400 days (or 400 to 300 working days). We apply a microsimulation method to calculate both static and behavioral ex-ante effects of the reform on employment, public finances and income inequality. Relying on previous empirical literature, we employ three benefit elasticity levels. Individual heterogeneity is added by weighting the elasticities with estimated employment probabilities. According to the static scenario, the reform increases income inequality, albeit marginally. Accounting for the behavioral response mitigates the effect on inequality and more than doubles the effect on public finances.

A microsimulation model to measure the impact of the economic crisis on household income

Purpose– The current economic crisis has significantly increased unemployment, showing higher persistence than expected. However, since microdata from household surveys are issued with delay, they do not allow a prompt analysis of the impact of the economic cycle on households’ living conditions. The purpose of this paper is to propose a microsimulation methodology to achieve an evaluation of the impact of economic shocks in terms of household’s living conditions to guide policy makers.Design/methodology/approach– The microsimulation technique developed in this paper is based on a nowcasting approach by using different sources of data and by taking into account a whole set of potential transitions across the different statuses of the labour market and the related changes in income. To validate this microsimulation method, the authors apply it to Italy, a country that has been deeply affected by the crisis.Findings– Data have been drawn from the European Statistics on Income and Living Conditions Survey for Italy (IT SILC) and from the Labour Force Survey for Italy. The latter data allow us to take into account the changes in the labour market status of individuals due to economic shocks. The validation results support the capability of the model to simulate the effect of the cycle before actual data on income are available.Social implications– The results obtained would encourage the use of the suggested methodology to anticipate the effect of the economic cycle on household’s income therefore enabling the design of effective policies to sustain household income with positive practical and social implications.Originality/value– Distinct from other microsimulation techniques the methodology proposed in this paper allows us to take into account behavioural effects and the change in the composition of employment and unemployment. Moreover, the authors contribute to the existing literature by considering a whole set of transitions across different labour market statuses and the related changes in income.