Computer simulations in health policy: methodology and applications in the management of chronic diseases

Among the main challenges of public-health policy makers is reducing gaps in the delivery of care, given limited human and monetary resources. In a public health setting, decision-analysis tools such as simulation models can be used to inform decision-makers in answering what-if policy questions in order to improve public health and clinical practice, optimize resource allocation, or guide funding and reimbursement decisions. Of the main public-health challenges in the United States is the burden of chronic infectious diseases. The prevalence and associated cost of chronic infectious diseases, such as hepatitis C virus (HCV) and sexually transmitted diseases (STDs) has increased in the United States due to rising life expectancy and social changes. Many of these diseases have effective therapies, but there are gaps in research on effective mitigation strategies. The public health significance of this dissertation was to apply rigorous decision-sciences methods using computer simulations in health services research and to expand the application of existing methods to answer real-world questions in health policy of chronic infectious diseases. In the first section of this dissertation, I quantified the the effects of new HCV therapies and updated screening guidelines on the burden of HCV and associated disease outcomes in the United States using an individual-level state-transition microsimulation model. The second section of this dissertation, estimated the status of HCV disease burden and the potential budget impact of various treatment strategies in the Pennsylvania Medicaid population using the HCV microsimulation model that was calibrated to Pennsylvania Medicaid according to the claims data from 2007–2012. The last section of this dissertation, included the development and maintenance of sexual partnership networks using an agent-based simulation modeling approach, according to serial cross-sectional data obtained from the 2007–2014 National Health and Nutrition Examination Survey. This study provides a tool for understanding the dynamics of sexual partnership networks which is critical to improve the impacts of STD mitigation strategies that focus on the sexual behaviors of individuals. In conclusion, this dissertation provided the details of two computer-simulation applications in health-related multi-disciplinary policy research, and delivers insights on how to use computer simulation in medical decision-sciences and policy problems

Comparative impact of platelet rich plasma and transforming growth factor-β on chondrogenic differentiation of human adipose derived stem cells

Introduction: Transforming growth factor-beta (TGF-β) is known as standard chondrogenic differentiation agent, even though it comes with undesirable side effects such as early hypertrophic maturation, mineralization, and secretion of inflammatory/angiogenic factors. On the other hand, platelet-rich plasma (PRP) is found to have a chondrogenic impact on mesenchymal stem cell proliferation and differentiation, with no considerable side effects. Therefore, we compared chondrogenic impact of TGF-β and PRP on adipose-derived stem cells (ADSCs), to see if PRP could be introduced as an alternative to TGF-β. Methods: Differentiation of ADSCs was monitored using a couple of methods including glycosaminoglycan production, miRNAs expression, vascular endothelial growth factor (VEGF)/tumor necrosis factor alpha (TNFα) secretion, alkaline phosphatase (ALP) and calcium content assays. Results: Accordingly, the treatment of differentiating cells with 5% (v/v) PRP resulted in higher glycosaminoglycan production, enhanced SOX9 transcription, and lowered TNFα and VEGF secretion compared to the control and TGF-β groups. Besides, the application of PRP to the media up-regulated miR-146a and miR-199a in early and late stages of chondrogenesis, respectively. Conclusion: PRP induces in vitro chondrogenesis, as well as TGF-β with lesser inflammatory and hypertrophic side effects

Risk factors associated with long covid syndrome: A retrospective study

Background: Recently, people have recognized the post-acute phase symptoms of the COVID-19. We investigated the long-term symptoms associated with COVID-19, (Long COVID Syndrome), and the risk factors associated with it. Methods: This was a retrospective observational study. All the consecutive adult patients referred to the healthcare facilities anywhere in Fars province from 19 February 2020 until 20 November 2020 were included. All the patients had a confirmed COVID-19 diagnosis. In a phone call to the patients, at least three months after their discharge from the hospital, we obtained their current information. The IBM SPSS Statistics (version 25.0) was used. Pearson Chi square, Fisher’s exact test, t test, and binary logistic regression analysis model were employed. A P value of less than 0.05 was considered to be significant. Results: In total, 4,681 patients were studied, 2915 of whom (62.3%) reported symptoms. The most common symptoms of long COVID syndrome were fatigue, exercise intolerance, walking intolerance, muscle pain, and shortness of breath. Women were more likely to experience long-term COVID syndrome than men (Odds Ratio: 1,268; 95% Confidence Interval: 1,122-1,432; P=0.0001), which was significant. Presentation with respiratory problems at the onset of illness was also significantly associated with long COVID syndrome (Odds Ratio: 1.425; 95% Confidence Interval: 1.177-1.724; P=0.0001). A shorter length of hospital stay was inversely associated with long COVID syndrome (Odds Ratio: 0.953; 95% Confidence Interval: 0.941-0.965; P=0.0001). Conclusion: Long COVID syndrome is a frequent and disabling condition and has significant associations with sex (female), respiratory symptoms at the onset, and the severity of the illness

Entrepreneurial orientation in exporter and non-exporter SMEs

This research is a quantitative study which is conducted in fruits and vegetables SMEs of Tehran Province in Iran. The province of Tehran, capital of Iran, is selected mainly because of the most recent formal national statistics, published by Statistic Center of Iran (SCI), show that more than 27 of all SMEs in Iran are activating in this area. The purpose of this study is a comparison of entrepreneurial orientations in exporter and non-exporter SMEs. For the purpose of data collection, a structured questionnaire was designed and generated from 76 managers of SMEs (44 exporters and 32 non-exporters). The software �Statistical Package for the Social Sciences� (SPSS 20) is used to analyze the data with the aim of assessing the difference between exporter and non-exporter SMEs by means of entrepreneurial orientations. The results of the survey show that all dimensions of Entrepreneurial Orientations in exporter and non-exporter are correlated and Pro-activeness, Autonomy and Competitive Aggressiveness among dimensions of entrepreneurial orientations have a significant difference between exporter and non-exporter SMEs

Green synthesis of zinc oxide nanoparticles: a comparison

Green synthesis of nanoparticles by biological systems especially plant extracts has become an emerging field in nanotechnology. In this study, zinc oxide nanoparticles were synthesized using Laurus nobilis L. leaves aqueous extract and two different zinc salts (zinc acetate and zinc nitrate) as precursors. The synthesized nanoparticles were characterized by Ultraviolet–Visible spectroscopy (UV–Vis), Fourier Transform Infrared Spectroscopy (FT-IR), X-Ray Diffraction analysis (XRD), Energy-Dispersive X-ray analysis (EDX) and Scanning Electron Microscopy (SEM). UV–Vis spectra showed typical absorption peaks in around 350 nm due to their large excitation binding energy at room temperature. Chemical bond formations of zinc oxide were confirmed by FT-IR analyses. XRD results revealed the formation of hexagonal wurtzite structure, and SEM analyses showed spherical shape with the average size (21.49, 25.26) nm for the synthesized nanoparticles by zinc acetate and zinc nitrate respectively. EDX analyses confirmed high purity for the synthesized nanoparticles

Estimated Impact of Targeted Pre-Exposure Prophylaxis: Strategies for Men Who Have Sex with Men in the United States

Pre-exposure prophylaxis (PrEP) effectively reduces human immunodeficiency virus (HIV) transmission. We aimed to estimate the impact of different PrEP prioritization strategies among Black and Latino men who have sex with men (MSM) in the United States, populations most disproportionately affected by HIV. We developed an agent-based simulation to model the HIV epidemic among MSM. Individuals were assigned an HIV incidence risk index (HIRI-MSM) based on their sexual behavior. Prioritization strategies included PrEP use for individuals with HIRI-MSM ≥10 among all MSM, all Black MSM, young (≤25 years) Black MSM, Latino MSM, and young Latino MSM. We estimated the number needed to treat (NNT) to prevent one HIV infection, reductions in prevalence and incidence, and subsequent infections in non-PrEP users avoided under these strategies over 5 years (2016−2020). Young Black MSM eligible for PrEP had the lowest NNT (NNT = 10) followed by all Black MSM (NNT = 33) and young Latino MSM (NNT = 35). All Latino MSM and all MSM had NNT values of 63 and 70, respectively. Secondary infection reduction with PrEP was the highest among young Latino MSM (53.2%) followed by young Black MSM (37.8%). Targeting all MSM had the greatest reduction in prevalence (14.7% versus 2.9%−3.9% in other strategies) and incidence (49.4% versus 9.4%−13.9% in other groups). Using data representative of the United States MSM population, we found that a strategy of universal PrEP use by MSM was most effective in reducing HIV prevalence and incidence of MSM. Targeted use of PrEP by Black and Latino MSM, however, especially those ≤25 years, had the greatest impact on HIV prevention