Risk factors of postoperative complications after radical cystectomy with continent or conduit urinary diversion in Armenia

To estimate the surgical volume and the incidence of in-hospital complications of RC in Armenia from 2005 to 2012, and to investigate potential risk factors of complications. The study utilized a retrospective chart review in a cohort of patients who had RC followed by either continent or conduit urinary diversion in all hospitals of Armenia from 2005 to 2012. A detailed chart review was conducted abstracting information on baseline demographic and clinical characteristics, surgical procedural details, postoperative management and in-hospital complications. Multivariable logistic regression analysis was applied to estimate the independent risk factors for developing ‘any postoperative complication’. The total study sample included 273 patients (mean age = 58.5 years, 93.4 % men). Overall, 28.9 % (n = 79) of patients had at least one in-hospital complication. The hospital mortality rate was 4.8 % (n = 13). The most frequent types of complications were wound-related (10.3 %), gastrointestinal (9.2 %) and infectious (7.0 %). The ischemic heart disease (OR = 3.3, 95 % CI 1.5–7.4), perioperative transfusion (OR = 2.0, 1.1–3.6), glucose level [OR = 0.71 (0.63–0.95)], and hospital type (OR = 2.3, 95 % CI 1.1–4.7) were independent predictors of postoperative complications. The rate of RC complications in Armenia was similar to those observed in other countries. Future prospective studies should evaluate the effect of RC complications on long-term outcomes and costs in Armenia. Policy recommendations should address the issues regarding surgeon training and hospital volume to decrease the risk of RC complications

Automatic multi-camera extrinsic parameter calibration based on pedestrian torsors

Extrinsic camera calibration is essential for any computer vision task in a camera network. Typically, researchers place a calibration object in the scene to calibrate all the cameras in a camera network. However, when installing cameras in the field, this approach can be costly and impractical, especially when recalibration is needed. This paper proposes a novel, accurate and fully automatic extrinsic calibration framework for camera networks with partially overlapping views. The proposed method considers the pedestrians in the observed scene as the calibration objects and analyzes the pedestrian tracks to obtain extrinsic parameters. Compared to the state of the art, the new method is fully automatic and robust in various environments. Our method detect human poses in the camera images and then models walking persons as vertical sticks. We apply a brute-force method to determines the correspondence between persons in multiple camera images. This information along with 3D estimated locations of the top and the bottom of the pedestrians are then used to compute the extrinsic calibration matrices. We also propose a novel method to calibrate the camera network by only using the top and centerline of the person when the bottom of the person is not available in heavily occluded scenes. We verified the robustness of the method in different camera setups and for both single and multiple walking people. The results show that the triangulation error of a few centimeters can be obtained. Typically, it requires less than one minute of observing the walking people to reach this accuracy in controlled environments. It also just takes a few minutes to collect enough data for the calibration in uncontrolled environments. Our proposed method can perform well in various situations such as multi-person, occlusions, or even at real intersections on the street

Automatic extrinsic calibration of camera networks based on pedestrians

Extrinsic camera calibration is essential for any computer vision tasks in a camera network. Usually, researchers place calibration objects in the scene to calibrate the cameras. However, when installing cameras in the field, this approach can be costly and impractical, especially when recalibration is needed. This paper proposes a novel accurate and fully automatic extrinsic calibration framework for camera networks with partially overlapping views. It is based on the analysis of pedestrian tracks without other calibration objects. Compared to the state of the art, the new method is fully automatic and robust. Our method detects human poses in the camera images and then models walking persons as vertical sticks. We propose a brute-force method to determine the pedestrian correspondences in multiple camera images. This information along with 3D estimated locations of the head and feet of the pedestrians are then used to compute the camera extrinsic matrices. We verified the robustness of the method in different camera setups and for both single pedestrian and multiple walking people. The results show that the proposed method can obtain the triangulation error of a few centimeters. Typically, it requires 40 seconds of collecting data from walking people to reach this accuracy in controlled environments and a few minutes for uncontrolled environments. As well as compute relative extrinsic parameters connecting the coordinate systems of cameras in a pairwise fashion automatically. Our proposed method could perform well in various situations such as multi-person, occlusions, or even at real intersections on the street

Methods for identifying health state transitions from administrative data: the case of metastasis in prostate cancer

Introduction Health administrative data are a rich source of population-based information, useful for building state transition models for medical decision making. These models require identification of health state transitions and associated times. Indirect methods are needed to predict this information, as it is rarely available in administrative data. Objectives and Approach We considered a set of criteria to identify transitions to metastasis for prostate cancer patients in administrative data, utilizing dates of diagnostic and medical billing codes for secondary malignancy, palliative radiation therapy, chemotherapy and bone disorders or procedures. We evaluated the criteria using the true date of metastasis from medical charts of 195 patients linked to health care administrative data in Ontario, Canada. We also built a recursive partitioning tree to optimally combine these criteria and construct rules for identifying metastatic patients. For the evaluation, both misclassification and discrepancy between true and predicted dates for the true positives were considered. Results Criteria involving chemotherapy drugs or hospital visits with secondary malignancy ICD10 diagnosis gave the best results, with high sensitivity and specificity. Criteria involving bone related problems, radiation therapy or diagnosis of metastatic cancer in physician billing data were very specific but not sensitive. The criterion involving prescriptions for narcotics was sensitive but not specific. The fitted tree was parsimonious involving only two of the criteria, while improving the accuracy over individual criteria. Most criteria gave a “delayed” prediction, with criterion based on chemotherapy giving on average the smallest delay, as well as exhibiting the least variability. Criteria involving narcotics and bone related problems predicted metastasis date very prematurely, probably triggered by conditions other than prostate cancer. Conclusion/Implications Several criteria from administrative databases satisfactorily classified prostate cancer patients with metastasis. A classification tree was built and improved the results over single criteria, demonstrating the added benefits in using advanced statistical learning methods for this task. However, “transition to metastasis” dates were predicted inaccurately, often with significant delay

Designing Randomized Clinical Trials for Rare Diseases

Objectives: 1) To evaluate the quality of randomized clinical trials (RCTs) in rare diseases using Juvenile Idiopathic Arthritis (JIA) as an example, 2) to evaluate the time to treatment response in patients with rheumatic diseases, 3) to evaluate the power of the Randomized Placebo-Phase Design (RPPD) under various response time distributions, and 4) to examine the use of Value of Information (VOI) methodology in the optimal design of clinical trials for rare disease using hemophilia prophylaxis with factor VIII as an example. Methods. The methods include a systematic review, a secondary analysis of data from an RCT and from a patient registry, a computer simulation study, and an evaluation of hypothetical RCT scenarios with VOI methodology. Results. The quality of RCTs in JIA based on selected quality indicators was poor with some positive changes over time. In the data sets used for the assessment of hazard distributions, the response times followed mostly generalized gamma or lognormal distributions. The impact of time-to-event distribution on the power of RCTs was assessed in computer simulations. Based on the simulation results, the highest sample sizes were observed for response times following the exponential distribution. In most scenarios, the parallel groups RCT design had higher power than the RPPD. The conclusion of the VOI analyses indicated that at threshold values lower than 400,000 the current evidence supported the use of on-demand therapy. Threshold values higher than 1,000,000 supported the use of tailored or alternate day prophylaxis. At threshold values between 400,000 - 1,000,000 the optimal decision varied from on-demand to prophylaxis therapies. Conclusions. New, more powerful and acceptable designs should be developed for rare diseases. When time-to-event outcomes are used, investigators should use various sources of information to evaluate response time distributions before the new trial is designed, and consider this information in sample size calculation and analysis. VOI methodology should be used in the planning stage of studies to determine the relevant costs and benefits of future research, and to determine the optimal trial parameters that maximize the cost-benefit trade-off.Ph

Capacitive Measurer of Linear Displacement

The features of constructing of a linear displacement measurer with differential capacitive transducer are considered. The measuring circuit is analyzed, which makes possible to implement a linear algorithm for determining the measured displacement. With an appropriate choice of the base element, in the production conditions the device can provide measurement of linear displacements with a limit of the permissible basic comparative error not exceeding 0.12 %

Sex differences in long-term outcomes of patients with percutaneous coronary intervention: the Armenian experience

The present study aimed at assessing sex differences in perioperative characteristics and 3-year event-free survival from major adverse cardiac and cerebrovascular events (MACCE) in patients with percutaneous coronary intervention (PCI) in Armenia. The study utilized an observational, retrospective cohort design enrolling patients who underwent PCI from 2006 to 2008 at a single center in Yerevan, Armenia. Major adverse cardiac and cerebrovascular events included all-cause mortality, myocardial infarction (MI), repeat revascularization, or stroke/transient ischemic attack. Among 485 participants included in the analysis, 419 (86%) were men. Women were older, more hypertensive, more obese, and had significantly higher rates of diabetes. At the end of follow-up, the incidence of MACCE was 37% for men and 33% for women (P=0.9). Based on the results from the adjusted Cox proportional hazards model, the independent predictors of MACCE included acute MI [hazard ratio (HR)=1.43, 95% confidence interval (CI): 1.02-2.00], arrhythmia (HR=1.64, 95% CI: 1.07-2.50), sex (HR=2.46, 95% CI: 1.08- 5.61), diabetes (HR=5.65, 95% CI: 2.14-14.95), and the interaction between sex and diabetes (HR=0.16; 95% CI: 0.05-0.47). Among diabetic patients, men had better event-free survival from MACCE (HR=0.40, 95% CI: 0.19-0.85) than women, whereas in patients without diabetes men had worse outcomes than women (95% CI: 1.08-5.62). In Armenia, the baseline profile of women undergoing PCI differed considerably from that of men. In patients with diabetes, women had worse outcomes at long-term follow-up, while the opposite was noted in patients without diabetes

Comparative Effectiveness of Complete Revascularization Versus Infarct Related Artery-only Percutaneous Coronary Revascularization for Multivessel Disease After ST-Segment Elevation Myocardial Infarction

Objectives: The purpose of this study was to evaluate the event free survival from major adverse cardiac events (MACE) for STsegment elevation myocardial infarction (STEMI) patients with multivessel disease as a function of whether they underwent infarctrelated artery (IRA) only percutaneous coronary intervention (PCI) or complete revascularization at index admission. Background: The optimal management of patients with STEMI and multivessel disease while undergoing primary percutaneous coronary intervention (P-PCI) is uncertain. Methods and Results: STEMI patients with multivessel disease undergoing P-PCI between April 1, 2012, and March 31, 2014, were subdivided into those who underwent in-hospital complete revascularization (n= 150) or IRA-only revascularization (n = 156). Complete revascularization was performed during the index admission of P-PCI. The primary endpoint was a composite of allcause death, recurrent myocardial infarction (MI), heart failure, and ischemia-driven revascularization within 24 months. Patient groups were differed at baseline by gender and prevalence of heart failure. The average door-to-balloon time was significantly higher in the complete revascularization group. The primary endpoint occurred in 11.0% of the complete revascularization group versus 23% in the IRA-only revascularization group (hazard ratio: 0.51; 95% confidence interval: 0.34 to 0.93; p =0.039). There was a significant reduction in death, a non-significant reduction in all primary endpoint components was seen. Conclusions: In patients presenting for P-PCI with multivessel disease, index admission complete revascularization significantly lowered the rate of the primary composite endpoint at 24 months compared with treating only the IRA

An investigation into the relationship between the commitment of employees and their performance. A study within the Information and Communications Technology industry

Employee commitment has been in the center of growing interests and studies for several decades. During this time different approaches and theories have been developed regarding this concept. In the same way the concept of employee performance related to the latter’s work has been the focus of attention due to a potential improvement that this term offers to an organization. A review of scientific literature explores how important it is to have committed employees and describes its impact on a company’s competitive advantage expressed through customer satisfaction, productivity, low employee turnover, tolerance to changes, low absenteeism, etc. Moreover, managing employees’ performance is also crucial related to the motivational theory with positive outcomes, such as employees’ relations, productivity, quality of the service or product, as well as financial performance of an organization. Besides, a number of authors have drawn attention to the need of exploring conceptually and empirically the relationship between employee commitment and performance. Even though, research has identified both positive and negative relationships between these two concepts, there still remain confusing points. In this thesis the relationship between employees’ commitment and performance in Information and Communications Technology industry in Armenia has been investigated. To note, no research related to this subject has been carried out in Armenia before. The critical review is followed by a field study in three ICT companies with an email-based interview conducted among 14 employees. As mentioned in the findings not only the importance of employee commitment to the firm but also the relationship and effects it has on employees’ performance as a key outcome have been identified. The findings are analyzed and discussed and conclusions are drawn at the end of the report

An investigation into the relationship between the commitment of employees and their performance. A study within the Information and Communications Technology industry

Employee commitment has been in the center of growing interests and studies for several decades. During this time different approaches and theories have been developed regarding this concept. In the same way the concept of employee performance related to the latter’s work has been the focus of attention due to a potential improvement that this term offers to an organization. A review of scientific literature explores how important it is to have committed employees and describes its impact on a company’s competitive advantage expressed through customer satisfaction, productivity, low employee turnover, tolerance to changes, low absenteeism, etc. Moreover, managing employees’ performance is also crucial related to the motivational theory with positive outcomes, such as employees’ relations, productivity, quality of the service or product, as well as financial performance of an organization. Besides, a number of authors have drawn attention to the need of exploring conceptually and empirically the relationship between employee commitment and performance. Even though, research has identified both positive and negative relationships between these two concepts, there still remain confusing points. In this thesis the relationship between employees’ commitment and performance in Information and Communications Technology industry in Armenia has been investigated. To note, no research related to this subject has been carried out in Armenia before. The critical review is followed by a field study in three ICT companies with an email-based interview conducted among 14 employees. As mentioned in the findings not only the importance of employee commitment to the firm but also the relationship and effects it has on employees’ performance as a key outcome have been identified. The findings are analyzed and discussed and conclusions are drawn at the end of the report