Application of the D-Fullness Technique for Breakdown Point Study of the Trimmed Likelihood Estimator to a Generalized Logistic Model

2000 Mathematics Subject Classification: 62J12, 62F35A new definition for a d-fullness of a set of functions is proposed and its equivalence to the original one given by Vandev [11] is proved. The breakdown point of the WTLk estimator of Vandev and Neykov [13] for a grouped binary linear regression model with generalized logistic link is studied.Research partially supported by contracts: PRO-ENBIS: GTC1-2001-4303

A national study of patient safety culture in hospitals in Bulgaria

Background. Patient safety culture (PSC) is an essential component of the care quality. An important contribution to the evaluation of hospital culture and the enhancement of PSC is the HSOPSC questionnaire elaborated by the Agency for Healthcare Research and Quality (AHRQ). Objective of the study. To assess the patient safety culture among hospital staff using the Bulgarian version of Hospital Survey on Patient Safety Culture (B-HSOPSC) and explore the areas of deficiencies and opportunities for improvement regarding this issue. Material and Methods. A national cross-sectional survey was conducted using a special developed Web-based platform. The questionnaire for assessment of HSOPSC includes 42 questions, organized in 12 domains. To the Bulgarian version of B-HSOPSC two new items were added. In total, 545 healthcare professionals from hospitals were enrolled. Data were exported to SPSS 17.0 and analyzed with descriptive statistics. Results. In general, results show positive assessments of patient safety culture, regardless of few of exceptions. The dimensions “Handoffs and transitions” and „Supervisor/manager expectations and actions promoting safety “showed the highest mean values, respectively 3.76±0.79 and 3.64±0.79, whereas the “Staffing” and “Non-punitive response to error” have received the lowest mean values, respectively 2.79±0.60 and 2.99±0.89. Conclusion. For the first time in Bulgaria the level of hospital patient safety was measured. Special attention should be paid to the staff turnover in hospital, as well as the introduction of a patient safety reporting system in our country

Trimmed Likelihood Estimation of the Parameters of the Generalized Extreme Value Distributions: a Monte-Carlo Study

2000 Mathematics Subject Classification: Primary 62F35; Secondary 62P99The applicability of the Trimmed Likelihood Estimator (TLE) proposed by Neykov and Neytchev to the extreme value distributions is considered. The effectiveness of the TLE in comparison with the classical MLE in the presence of outliers in various scenarios is illustrated by an extended simulation study. The FAST-TLE algorithm developed by Neykov Müller is used to get the parameter estimate. The computations are carried out in the R environment using the packages ismev originally developed by Coles and ported in R by Stephenson.The work of N. Neykov and P. Neytchev is partially supported by the Ministry of Education, Science and Culture of Republic of Bulgaria, grant MM 1103/2001. Partialy supported by Pro-ENBIS GTC1 -2001-43031

The EUROPEP questionnaire for patient’s evaluation of general practice care: Bulgarian experience

Aim To validate the Bulgarian EUROPEP-questionnaire and its implementation to measure patient evaluation of general practice care in Bulgarian population. Methods A multicenter cross-sectional study was conducted at twenty five primary care practices from South-Central Region of Bulgaria. A total of 1000 adult patients aged over 18 years and visiting the practice for more than a year were approached consecutively to take part in the study. The internal consistency and test-retest reliability of the EUROPEP questionnaire were evaluated. To confirm the construct validity of the questionniare, еxplanatory factor analysis was performed. Results Cronbach’alpha for “clinical behaviour” is 0.95 and for “organisation of care” 0.81. Factor analysis identifed two factors, which accounted for 77.0% of the total variation in these items. On average, 58.7% of respondents rated the level of care received as excellent. The waiting time in the waiting room was the item most poorly rated (33.8%). The item “keeping patients’ records and data confidential” was the most highly rated (88.8%). Patients were less satisfied with “providing quick services for urgent health problems” (78.5% excellent or good) and “getting an appropriate for them appointment” (76.2% excellent or good). Conclusion Two scales with satisfactory psychometric properties were established in the Bulgarian version of the EUROPEP-questionnaire. The study identified areas requiring improvement in general practice, such as reduction in waiting times and obtaining patient’s convenience appointment

Machine learning and word sense disambiguation in the biomedical domain: design and evaluation issues

BACKGROUND: Word sense disambiguation (WSD) is critical in the biomedical domain for improving the precision of natural language processing (NLP), text mining, and information retrieval systems because ambiguous words negatively impact accurate access to literature containing biomolecular entities, such as genes, proteins, cells, diseases, and other important entities. Automated techniques have been developed that address the WSD problem for a number of text processing situations, but the problem is still a challenging one. Supervised WSD machine learning (ML) methods have been applied in the biomedical domain and have shown promising results, but the results typically incorporate a number of confounding factors, and it is problematic to truly understand the effectiveness and generalizability of the methods because these factors interact with each other and affect the final results. Thus, there is a need to explicitly address the factors and to systematically quantify their effects on performance. RESULTS: Experiments were designed to measure the effect of "sample size" (i.e. size of the datasets), "sense distribution" (i.e. the distribution of the different meanings of the ambiguous word) and "degree of difficulty" (i.e. the measure of the distances between the meanings of the senses of an ambiguous word) on the performance of WSD classifiers. Support Vector Machine (SVM) classifiers were applied to an automatically generated data set containing four ambiguous biomedical abbreviations: BPD, BSA, PCA, and RSV, which were chosen because of varying degrees of differences in their respective senses. Results showed that: 1) increasing the sample size generally reduced the error rate, but this was limited mainly to well-separated senses (i.e. cases where the distances between the senses were large); in difficult cases an unusually large increase in sample size was needed to increase performance slightly, which was impractical, 2) the sense distribution did not have an effect on performance when the senses were separable, 3) when there was a majority sense of over 90%, the WSD classifier was not better than use of the simple majority sense, 4) error rates were proportional to the similarity of senses, and 5) there was no statistical difference between results when using a 5-fold or 10-fold cross-validation method. Other issues that impact performance are also enumerated. CONCLUSION: Several different independent aspects affect performance when using ML techniques for WSD. We found that combining them into one single result obscures understanding of the underlying methods. Although we studied only four abbreviations, we utilized a well-established statistical method that guarantees the results are likely to be generalizable for abbreviations with similar characteristics. The results of our experiments show that in order to understand the performance of these ML methods it is critical that papers report on the baseline performance, the distribution and sample size of the senses in the datasets, and the standard deviation or confidence intervals. In addition, papers should also characterize the difficulty of the WSD task, the WSD situations addressed and not addressed, as well as the ML methods and features used. This should lead to an improved understanding of the generalizablility and the limitations of the methodology

Linguistic Validation and Cultural Adaptation of Bulgarian Version of Hospital Survey on Patient Safety Culture (HSOPSC)

BACKGROUND: Patient safety (PS) is one of the essential elements of health care quality and a priority of healthcare systems in most countries. Thus the creation of validated instruments and the implementation of systems that measure patient safety are considered to be of great importance worldwide.AIM: The present paper aims to illustrate the process of linguistic validation, cross-cultural verification and adaptation of the Bulgarian version of the Hospital Survey on Patient Safety Culture (B-HSOPSC) and its test-retest reliability.METHODS: The study design is cross-sectional. The HSOPSC questionnaire consists of 42 questions, grouped in 12 different subscales that measure patient safety culture. Internal con­sistency was assessed using Cronbach’s alpha. The Wilcoxon signed-rank test and the split-half method were used; the Spear­man-Brown coefficient was calculated.RESULTS: The overall Cronbach’s alpha for B-HSOPSC is 0.918. Subscales 7 Staffing and 12 Overall perceptions of safety had the lowest coefficients. The high reliability of the instrument was confirmed by the Split-half method (0.97) and ICC-coefficient (0.95).  The lowest values of Spearmen-Broun coefficients were found in items A13 and A14.CONCLUSION: The study offers an analysis of the results of the linguistic validation of the B-HSOPSC and its test-retest reliability. The psychometric characteristics of the questions revealed good validity and reliability, except two questions. In the future, the instrument will be administered to the target population in the main study so that the psychometric properties of the instrument can be verified

Academic Staff Satisfaction with their Work: A Cross-Sectional Study in a Medical University

BACKGROUND: Employees' work satisfaction, combined with democratic management, are important predictors of future productivity in any organisation. AIM: The aim of this study is to investigate job satisfaction in academic staff as well as the associated working environment factors, using an original self-administered questionnaire. METHODS: A cross-sectional survey was conducted using an original standardised questionnaire. It involved 370 academic staff members at one of the five medical universities in Bulgaria. The questionnaire consists of 17 items (including occupational hazards, management style, conflict solving and demographic characteristics) rated on a 5-point Likert scale. RESULTS: The results revealed that the majority of academic staff (71.7%) works in a risky environment. Employees indicate that “mental strainâ€, “work with chemical agents and dust†and “work with biological hazards†are the most common risk factors. Democratic leadership and cooperation are most commonly applied management styles. CONCLUSION: The instrument for the measurement of job satisfaction revealed high values of psychometric characteristics for reliability and validity. The study found a high level of satisfaction of academics with their working conditions. It is necessary to conduct similar studies periodically to detect more precisely the decrease in academic staff work satisfaction and take timely and adequate measures to improve it

FibroSURE as a noninvasive marker of liver fibrosis and inflammation in chronic hepatitis B

BACKGROUND: Noninvasive markers of liver fibrosis have not been extensively studied in patients with chronic hepatitis B virus (HBV) infection. Our aim was to evaluate the capacity of FibroSURE, one of the two noninvasive fibrosis indices commercially available in the United States, to identify HBV infected patients with moderate to severe fibrosis. METHODS: Forty-five patients who underwent liver biopsy at a single tertiary care center were prospectively enrolled and had FibroSURE performed within an average interval of 11 days of the biopsy. RESULTS: Of the 45 patients, 40% were Asian, 40% were African American, and 13% were Caucasian; 27% were co-infected with HIV and 67% had no or mild fibrosis. We found FibroSURE to have moderate capacity to discriminate between patients with moderate to high fibrosis and those with no to mild fibrosis (area under receiver operating characteristic [AUROC] curve = 0.77; 95% confidence interval [CI] [0.61, 0.92]). When we combined the fibrosis score determined by FibroSURE with aspartate aminotransferase (AST) measurements and HIV co-infection status, the discriminatory ability significantly improved reaching an AUROC of 0.90 (95% CI [0.80, 1.00]). FibroSURE also had a good ability to differentiate patients with no or mild from those with moderate to high inflammation (AUROC = 0.83; 95% CI [0.71, 0.95]). CONCLUSIONS: FibroSURE in combination with AST levels has an excellent capacity to identify moderate to high fibrosis stages in chronic HBV-infected patients. These data suggest that FibroSURE may be a useful substitute for liver biopsy in chronic HBV infection

A national study of patient safety culture in hospitals in Bulgaria

Dept, of Health management and health economic, Medical University Plovdiv, Bulgaria. Congresul consacrat aniversării a 75-a de la fondarea Universității de Stat de Medicină și Farmacie „Nicolae Testemițanu” din Republica Moldova, Ziua internațională a științei pentru pace și dezvoltareIntroduction Patient safety culture (PSC) is an essential component of the care quality. An important contribution to the evaluation of hospital culture and the enhancement of PSC is the HSOPSC questionnaire elaborated by the Agency for Healthcare Research and Quality (AHRQ) [1]. The questionnaire displays reliable psychometric characteristics and has been validated in more than 20 countries. Objective This study aimed to assess the patient safety culture among hospital staff using the Bulgarian version of Hospital Survey on Patient Safety Culture (B-HSOPSC) and explore the areas of deficiencies and opportunities for improvement regarding this issue. Methods A national cross-sectional survey was conducted using a special developed Internet-based software platform. The questionnaire for assessment of Hospital Survey on Patient Safety Culture (HSOPSC) includes 42 questions, organized in 12 domains. To the Bulgarian version of BHSOPSC two new items were added [2]. In total, 545 healthcare professionals from hospitals in different regions of Bulgaria were enrolled. The data were exported to SPSS 17.0 statistical software and analyzed with descriptive statistics. Results In general, results show positive assessments of patient safety culture, regardless of few of exceptions. The dimensions "Handoffs and transitions" and „Supervisor/manager expectations and actions promoting safety " showed the highest mean values, respectively 3.76+0.79 and 3.64+0.79, whereas the "Staffing" and "Non-punitive response to error" have received the lowest mean values, respectively 2.79+0.60 and 2.99+0.89. Conclusion For the first time in Bulgaria, with the aid of a web-based platform to report adverse events and errors in medical practice, the level of hospital patient safety was measured. Special attention should be paid to the staff turnover in hospital, as well as the introduction of a patient safety reporting system in our country. References 1. Sorra JS, Nieva VF. Hospital Survey on Patient Safety Culture. Rockville, MD: Agency for Healthcare Research and Quality; 2004. [Accessed January 23,2020]. 2. Stoyanova, R., Dimova, R., Tarnovska, M., & Boeva, T. (2018). Linguistic validation and cultural adaptation of Bulgarian version of hospital survey on patient safety culture (HSOPSC). Open access Macedonian journal of medical sciences, 6(5):925-930

The Survey of Health Care Managers’ Attitude towards the Implementation of Information and Communication System for the Registration of Medical Errors

The aim of the study has been to examine attitudeand motivation of managers of Health Care Establishments forthe implementation of information and communication systemfor the registration and reporting of medical errors.A sociological method: anonymous inquiry sent by e-mail or bypost has been used to register the initial information. More thanhalf of the health care managers (59.6% (62)) are willing toimplement an information system for the registration of medicalerrors in their respective health care establishment