Using machine learning algorithms and techniques for defining the impact of affective temperament types, content search and activities on the internet on the development of problematic internet use in adolescents' population.

Background: By using algorithms and Machine Learning - ML techniques, the aim of this research was to determine the impact of the following factors on the development of Problematic Internet Use (PIU): sociodemographic factors, the intensity of using the Internet, different contents accessed on the Internet by adolescents, adolescents' online activities, life habits and different affective temperament types. Methods: Sample included 2,113 adolescents. The following instruments were used: questionnaire about: socio-demographic characteristics, intensity of the Internet use, content categories and online activities on the Internet; Facebook (FB) usage and life habits; The Internet Use Disorder Scale (IUDS). Based on their scores on the scale, subjects were divided into two groups - with or without PIU; Temperament Evaluation of Memphis, Pisa, Paris, and San Diego scale for adolescents (A-TEMPS-A). Results: Various ML classification models on our data set were trained. Binary classification models were created (class-label attribute was PIU value). Models hyperparameters were optimized using grid search method and models were validated using k-fold cross-validation technique. Random forest was the model with the best overall results and the time spent on FB and the cyclothymic temperament were variables of highest importance for these model. We also applied the ML techniques Lasso and ElasticNet. The three most important variables for the development of PIU with both techniques were: cyclothymic temperament, the longer use of the Internet and the desire to use the Internet more than at present time. Group of variables having a protective effect (regarding the prevention of the development of PIU) was found with both techniques. The three most important were: achievement, search for contents related to art and culture and hyperthymic temperament. Next, 34 important variables that explain 0.76% of variance were detected using the genetic algorithms. Finally, the binary classification model (with or without PIU) with the best characteristics was trained using artificial neural network. Conclusion: Variables related to the temporal determinants of Internet usage, cyclothymic temperament, the desire for increased Internet usage, anxious and irritable temperament, on line gaming, pornography, and some variables related to FB usage consistently appear as important variables for the development of PIU.

Healthcare Professionals' Knowledge and Behaviors Regarding Drug-Dietary Supplement and Drug-Herbal Product Interactions.

Given the widespread use of dietary supplements (DS) and herbal products (HP), healthcare professionals (HCPs) will increasingly encounter patients who use these preparations with conventional drugs and who need their services to reduce the consequences of adverse therapeutic outcomes. The aim of our survey was to assess the knowledge and behaviors of HCPs regarding the risk of potential drug−dietary supplement (DDSIs) and drug−herbal product (DHPIs) interactions. This cross-sectional survey collected data via on paper-based questionnaire among general practitioners (GPs) (n = 105), specialty doctors (n = 87) and nurses (n = 154). The HCPs were mostly familiar with the interaction of doxycycline with magnesium (83%) and were least familiar with interaction of warfarin with glucosamine (14%). The results on DDSIs and DHPIs knowledge showed that GPs scored significantly higher than nurses (p < 0.001 and p = 0.003, respectively), while specialty doctors scored significantly higher than nurses only on DDSIs knowledge (p < 0.001). Only 28% of respondents reported that they often or always ask patients on drug therapy about the use of DS or HP, and 25% of respondents record such data in the medical documentation of patients. Our results showed that HCPs have sufficient knowledge about most major DDSIs and DHPIs, but insufficient knowledge about most moderate interactions. However, their overall knowledge and behavior regarding the risk of these interactions indicate the need for further continuing education and training.

Effects of problem-based learning modules within blended learning courses in medical statistics - A randomized controlled pilot study.

Problem-based learning (PBL) allows students to learn medical statistics through problem solving experience. The aim of this study was to assess the efficiency of PBL modules implemented in the blended learning courses in medical statistics through knowledge outcomes and student satisfaction. The pilot study was designed as a randomized controlled trial that included 53 medical students who had completed all course activities. The students were randomized in two groups: the group with access to PBL modules within the blended learning course (hPBL group) and the group without access to PBL modules-only blended learning course (BL group). There were no significant differences between the groups concerning socio-demographic characteristics, previous academic success and modality of access to course materials. Students from hPBL group had a significantly higher problem solving score (p = 0.012; effect size 0.69) and the total medical statistics score (p = 0,046; effect size 0.57). Multivariate regression analysis with problem solving as an outcome variable showed that problem solving was associated with being in hPBL group (p = 0.010) and having higher grade point average (p = 0.037). Multivariate regression analysis with the medical statistics score as an outcome variable showed the association between a higher score on medical statistics with access to PBL modules (p = 0.045) and a higher grade point average (p = 0.021). All students in hPBL group (100.0%) considered PBL modules useful for learning medical statistics. PBL modules can be easily implemented in the existing courses within medical statistics using the Moodle platform, they have high applicability and can complement, but not replace other forms of teaching. These modules were shown to be efficient in learning, to be well accepted among students and to be a potential missing link between teaching and learning medical statistics. The authors of this study are planning to create PBL modules for advanced courses in medical statistics and to conduct this study on other universities with a more representative study sample, with the aim to overcome the limitations of the existing study and confirm its results.

The Development of Temperament Evaluation of Memphis, Pisa, Paris, and San Diego - Auto-questionnaire for Adolescents (A-TEMPS-A) in a Serbian Sample.

BACKGROUND: Previous studies suggest that temperament features of adolescents may be good predictors of the development of future psychopathology in this population. The aim of the study was to adapt the content and validate the psychometric properties of the Temperament Evaluation of Memphis, Pisa, Paris, and San Diego - Auto-questionnaire in a sample of Serbian adolescents. SUBJECTS AND METHODS: The sample included 2113 adolescents, 56% girls and 44% boys, average age 16.73±0.47, attending 48 Serbian secondary schools. The base for the development of this scale included Serbian standardised versions as well as the TEMPS-I, Interview version. RESULTS: The final scale is comprised of 36 items, with six factors (depressive, cyclothymic, hyperthymic, irritable, and anxious-cognitive/somatic) explaining 39.9% of the total variance, the internal consistency coefficient α=0.77, and the average test-retest coefficient (rho=0.84). The correlations among the temperaments ranged from weak to moderate, with the highest positive correlations between the depressive, cyclothymic and anxious scales. The highest values were detected on hyperthymic and the lowest on depressive temperament. Significantly higher scores of depressive, cyclothymic and anxious temperaments were detected in girls, whereas boys had higher scores on the hyperthymic scale. CONCLUSIONS: The scale has shown good psychometric properties, which encourages its further use in adolescent population. The results show certain specific features of this population, such as higher scores on all temperament types than the ones in student and adult population and a tendency of socially desirable answers.

Analysis of expired medications in Serbian households.

INTRODUCTION: An ongoing issue of expired medications accumulating in some households is a universal problem around the world. The aim of the study was to investigate the extent and structure of expired medications in Serbian households, and to determine which therapeutic groups generated the most waste. METHODS: This was an observational, cross-sectional study conducted in households in the city of Novi Sad, Serbia. The study had been performed over 8 month period (December 2011 - July 2012) and it consisted of personal insights into the medication inventory in households. RESULTS: Of 1008 families, 383 agreed to participate and complete the questionnaire (38.3% response rate). In almost a half of households (44.4%), expired medications were maintained. The amount of expired medications was 402 items, corresponding to 9.2% of total medications presented in surveyed households. The majority of expired medications (64.7%) was in solid dosage (tablets, capsules, granules, lozenges), following semisolid (ointments, creams, gel, suppositories) and liquid dosage forms (drops, syrups). Expired medications in the households belonged mostly to 3 categories: antimicrobials for systemic use (16.7%), dermatological preparation (15.9%) and medications for alimentary tract and metabolism (14.2%). CONCLUSIONS: This study revealed that there were relatively large quantities of expired medications in Serbian households, with a high prevalence of antibiotics for systemic use, anti-inflammatory and antirheumatic products, and medications for alimentary tract and metabolism.

Improving Education in Medical Statistics: Implementing a Blended Learning Model in the Existing Curriculum.

BACKGROUND: Although recent studies report on the benefits of blended learning in improving medical student education, there is still no empirical evidence on the relative effectiveness of blended over traditional learning approaches in medical statistics. We implemented blended along with on-site (i.e. face-to-face) learning to further assess the potential value of web-based learning in medical statistics. METHODS: This was a prospective study conducted with third year medical undergraduate students attending the Faculty of Medicine, University of Belgrade, who passed (440 of 545) the final exam of the obligatory introductory statistics course during 2013-14. Student statistics achievements were stratified based on the two methods of education delivery: blended learning and on-site learning. Blended learning included a combination of face-to-face and distance learning methodologies integrated into a single course. RESULTS: Mean exam scores for the blended learning student group were higher than for the on-site student group for both final statistics score (89.36±6.60 vs. 86.06±8.48; p = 0.001) and knowledge test score (7.88±1.30 vs. 7.51±1.36; p = 0.023) with a medium effect size. There were no differences in sex or study duration between the groups. Current grade point average (GPA) was higher in the blended group. In a multivariable regression model, current GPA and knowledge test scores were associated with the final statistics score after adjusting for study duration and learning modality (p<0.001). CONCLUSION: This study provides empirical evidence to support educator decisions to implement different learning environments for teaching medical statistics to undergraduate medical students. Blended and on-site training formats led to similar knowledge acquisition; however, students with higher GPA preferred the technology assisted learning format. Implementation of blended learning approaches can be considered an attractive, cost-effective, and efficient alternative to traditional classroom training in medical statistics.

Distribution and mobility of heavy elements in floodplain agricultural soils along the Ibar River (Southern Serbia and Northern Kosovo). Chemometric investigation of pollutant sources and ecological risk assessment.

This work investigates the influence of a high-magnitude flood event on heavy elements (HEs) pollution and mobility in the agricultural soils along Ibar River in Southern Serbia and Northern Kosovo. The study area was one of the most important Pb/Zn industrial regions in Europe. Soil samples (n = 50) collected before and after the floods in May 2014 were subjected to the sequential extraction procedure proposed by the Community Bureau of Reference (BCR). The results indicated that the floods significantly increased not only the pseudo total concentrations of HEs in the soil but also their mobile and potentially bioavailable amounts. Moreover, higher concentrations (both pseudo total and potentially bioavailable) were found in the agricultural soils closer to the industrial hotspots. Principal component analysis and hierarchical cluster analysis successfully grouped the analyzed elements according to their anthropogenic or natural origin. The floods significantly increased the potential ecological risk of HEs associated with Pb/Zn industrial activities in the study area. The potential ecological risk of Cd after the floods was highest and should be of special concern.

Meta-analysis of the changes in correlations between depression instruments used in longitudinal studies.

BACKGROUND: Correlations between instruments measuring the same construct reflect their concurrent validity. Little is known about changes in correlations between such instruments employed in studies with repeated assessment. The aim of this meta-analysis was to examine the changes in correlations between depression instruments in the course of longitudinal studies. METHODS: A literature search was conducted using MEDLINE and PsycINFO for the period from 1960 to 2013. The total number of collected articles was 3723, of which 61 were included. Three meta-analyses were performed for the changes in correlations between each pair of the three depression scales: Hamilton Rating Scale for Depression (HAMD), Montgomery-Asberg Depression Rating Scale (MADRS) and Beck Depression Inventory (BDI). The effect size in these meta-analyses was obtained by the z-transformation of correlation coefficients. RESULTS: Correlations between depression scales increased over time in 52 studies. Significant changes in correlation coefficients were found for correlations between HAMD and BDI (p<0.001) and for correlations between HAMD and MADRS (p<0.001). An increase in correlations between the scales was associated with a decrease in depression scores and increase in their variability. LIMITATIONS: Univariable and multivariable meta-regression models were not obtained in all three meta-analyses because of the lack of data. CONCLUSIONS: A finding that correlations between depression instruments tended to increase over time has significant implications for assessment of the concurrent validity of these instruments. In longitudinal designs it is important to estimate correlations between depression scales over time because different thresholds for scale correlations indicate acceptable concurrent validity at different times.

The Burden of Gastroesophageal Reflux Disease on Patients' Daily Lives: A Cross-Sectional Study Conducted in a Primary Care Setting in Serbia.

INTRODUCTION: Recent data from the studies conducted in the Western countries have proved that patients with gastroesophageal reflux disease have significantly impaired health-related quality of life compared to general population. OBJECTIVE: The study is aimed at evaluating the burden of reflux symptoms on patients'health-related quality of life. METHODS: The study involved 1,593 patients with diagnosed gastroesophageal reflux disease.The Serbian version of a generic self-administered Centers for Disease Control and Prevention questionnaire was used. Statistical analyses included descriptive statistics, Pearson chi-square test and a multiple regression model. RESULTS: Among all participants, 43.9% reported fair or poor health. Mean value of unhealthy days during the past 30 days was 10.4 days, physically unhealthy days 6.4 days, mentally unhealthy days 5.3 days and activity limitation days 4.3 days. Furthermore, 24.8% participants reported having ≥ 14 unhealthy days, 14.9% had 14 physically unhealthy days, 11.8% reported 14 mentally unhealthy days, and 9.4% had ≥ 14 activity limitation days. CONCLUSION: This study addressed complex relationships between reflux symptoms and patients'impaired everyday lives.

Analysis of the factors influencing development of urinary tract infections in patients with spinal cord injuries.

BACKGROUND/AIM: Urinary tract infections are still the most frequent complications in patients with spinal cord injury (SCI). The aim of this study was to analyze the factors influencing development of urinary tract infections during rehabilitation in patients with SCI. METHODS: This retrospective case/control study including 540 patients with SCI which were rehabilitated in the Clinic for Rehabilitation "Dr Miroslav Zotovic" between January 2000 and December 2009. We used patient files and other available medical documentation for obtaining information contained in this study, such as the manner of bladder emptying, the type of neurological disorder of the bladder, the neurological level and completeness of a lesion, the injury etiology, treatment method, secondary complications and associated injuries, kidney and bladder calculosis, age and sex. RESULTS: Out of the total number of patients included in the study, 152 (28.1%) were without urinary tract infections, whereas 388 (71.9%) had urinary tract infections. There were 389 (72%) male and 151 (28%) female patients. The average age of patients without urinary tract infections was 51.0 ± 15.4 years, whereas the mean age of patients with urinary tract infections was 44.3 ± 16.9 years. The results of our study showed that the occurrence of urinary tract infections during rehabilitation in patients with SCIs was associated with the following factors: combined injuries (OR = 3.5), anemia (OR = 5.67), type of the bladder functional disorder (OR = 40-60) and crystals in urine (OR = 7.54). CONCLUSION: The physicians should take precautions and try to make the early diagnosis and rapid appropriate treatment of urinary tract infections in patients with SCI who also have functional bladder disorder, combined spinal injuries, anemia or urine crystals.

Analysis of the factors influencing functional outcomes in patients with spinal cord injury.

[Purpose] The extent of functional independence ultimately achieved by an individual patient will be influenced by a variety of medical and non-medical factors. [Subjects and Methods] this study included 419 patients with spinal cord lesions treated in the Clinic for Rehabilitation "Dr M. Zotovic", Belgrade, Serbia, from January 2000 to December 2009. The patients were divided in two groups according to achievement of increase in Functional Independence Measure (FIM) score of more than 13 at discharge compared to admission. A variety of clinical variables were followed in both groups. [Results] one hundred twenty-one patients (28.9%) showed improvements in FIM score of ≤13, while 298 (71.1%) patients showed an increases in FIM score of >13 at discharge compared to admission. Better functional recovery was observed in patients with non-traumatic spinal cord lesions, lower neurological levels of the lesion (OR = 6.07), and in patients treated surgically, but the level of the spinal cord lesion was the most influential factor affecting outcome. [Conclusion] the patients with spinal cord lesions should not only be grouped by traumatic and non-traumatic lesions only, but also sub-categorized, according to the etiology, level of injury and treatment method.

[Morbidity patterns of workers employed in pharmaceutical-chemical industry].

INTRODUCTION: Work in pharmaceutical-chemical industry is characterized by exposure to numerous hazards, both physical (microclimate, illumination, noise) and chemical (organic solvents). Organic solvents can cause damage to many organic systems and have carcinogenic, teratogenic and mutagenic effects. OBJECTIVE: The aim of this study was to analyze patterns of chronic morbidity of workers employed in pharmaceutical-chemical industry during 2002. METHOD: The study was conducted in the pharmaceutical-chemical industry "Zdravlje" Leskovac in 2002. A total of 143 workers in workplaces with special working conditions exposed to chemical hazards as well as 40 workers from control group took part in the study. The physical examinations of the participants were performed at the Department of Occupational Health in Health Center, Leskovac. RESULTS: Heart diseases were the most frequent both among exposed workers (17.8%) and in control group (33.3%). Respiratory diseases were at the second place (16.9% in the exposed group, and 7.4% in control group). Arterial hypertension was diagnosed in 14.7% workers occupationally exposed to hazards, and in 12.5% workers from control group (p > 0.05). Chronic bronchitis was diagnosed in 175% of the exposed workers and in only 5.0% of controls (p > 0.05). The highest prevalence of diseases in both groups was observed among workers aged 40-49 years, with 20-29 years of exposure working time. 73.4% of the exposed workers and 85% of control workers were capable of work (p > 0.05). CONCLUSION: Workers occupationally exposed to hazards in pharmaceutical-chemical industry have higher prevalence of various diseases compared to non-exposed workers, which can be the result of work, working conditions and work activity. Preventive measures should be directed towards the decrease of occupational hazards and unfavorable working conditions and increase of work protection. Regular physical examinations of workers are of prime importance for the prevention of occupational morbidity, traumatism and invalidity.