Aim To investigate knowledge, attitudes and practice towards COVID-19 among selected population. Methods An anonymous online questionnaire based on a Chinese study was distributed via online social media platforms among general population of Bosnia and Herzegovina, Germany, India, Kosovo and Romania. Results In total 1032 subjects, predominately females, 615 (59.6%) with a mean age of 31.23±12.94 years, single, 705 (68.3%), with high school degree or lower, 469 (45.4%), students, 528 (51.1%) and living in an urban environment, 824 (79.8%), have completed the survey. The median knowledge score was 10.0 (range 0-12). Being male (β: -0.437; p=0.003) and older (β: -0.028; p<0.001) were associated with lower knowledge scores, while being single (β: 1.026; p<0.001) and mental labour employee (β: 0.402; p=0.032) were associated with higher knowledge scores. The vast majority of subjects had not visited crowded places, 630 (61.0%) and wearing masks when they were going out, 928 (89.9%). Being female (OR=0.731; p=0.022), having higher knowledge scores (OR=0.929; p=0.017) and being a mental labour employee (OR=0.713; p=0.031) decreased the exposure to crowded places. High school or lower education level (OR=0.616; p=0.024) decreased the action of wearing a mask in public places, while higher knowledge scores (OR=1.112; p=0.013) increased it. Conclusion Our study suggests that residents of the selected regions have had good knowledge, pessimistic attitudes and relatively appropriate practices towards COVID-19 during the second wave of the outbreak.

BACKGROUND Indoor air quality (IAQ) in classrooms affects children's health and academic perfor-mance. The aim of this pilot study was to determine IAQ in elementary schools different in their inter-nal and external characteristics, in settings of COVID-19 epidemics. METHODS IAQ parameters: fine particulate matter (PM2,5) mass concentration, CO2 concentration, tempera-ture and relative humidity were measured in parallel in four elementary schools/classrooms during October (non-heating season) and four months (including holiday in January) of heating season. IAQ parameters were measured in settings of anti-epidemic restrictions (≤13 students in classroom, frequent ventilation). RESULTS During October, except in one school, PM2,5 concentrations were below the upper recommended value (25 μg/m³), but started rising in all schools in the heating season. The highest concentrations of PM2,5 were registered in two schools with closed or shortly opened windows. CO2 concentrations were mostly in the recommended range (up to 1000ppm) except in the school with constantly closed windows and in three schools in February when concentrations were higher. Except in one, the same school, and in January, both temperature and relative humidity were out of the recommended range (24,0-27,0°C in non-heating; 20,0-24,0°C in heating season; and 45-55%), with temperature mainly above and relative humidity mainly below it in three schools. The largest deviation in temperature and relative humidity were registered in urban schools. Registered differ-ences may be explained by different internal and external characteristics. CONCLUSION Despite anti-epidemic restrictions, most of the measured IAQ parameters were out of the recom-mended values in heating season. In addition, further deterioration of IAQ could be expected if all students had been presented in the classroom. Finally, to assure a healthy school environment in heating season, further optimisation of both indoor and outdoor conditions is needed in both pandemic and non-pandemic settings.

BACKGROUND Occurrence of symptoms of fear and depression among general population during the outbreak of COVID-19 seems to present an emerging problem worldwide. The aim of this study was to examine levels of fear and depressive symptoms in association with COVID-19 outbreak and to assess other contributing factors in the population of Bosnia and Herzegovina. SUBJECTS AND METHODS Link to an anonymous questionnaire, mainly based on The Fear of COVID-19 Scale (Ahorsu et al. 2020) and two-item and nine-item Patient Health Questionnaires (PHQs) (Maurer et al. 2018) (background information, fear assessment and information regarding depression) was distributed online to general population of Bosnia and Herzegovina. RESULTS Out of 1201 respondents, 217 (18.0%) reported experiencing fear and 341 (28.4%) reported having symptoms of depression during COVID-19 outbreak. The mean age of the subjects was 30.57±11.26. Being older (OR=1.044; 95% CI 1.031-1.057; p<0.001) and having moderate to severe depressive symptoms (OR=1.093; 95% CI 1.067-1.120; p<0.001) were independent significant predictors for developing fear; living in rural environment (OR=0.551; 95% Cl 0.325-0.935; p=0.0027) significantly decreased the risk of developing fear; being female (OR=1.750; 95% CI 1.242-2.466; p=0.001), unemployed (OR=1.557; 95% CI 1.040-2.330; p=0.032) or student (OR=1.943; 95% CI 1.450-2.604; p<0.001) were independent significant predictors for developing moderate to severe depressive symptoms in association with COVID-19. Mann Whitney U-test showed that being older was statistically associated with fear (p<0.001) and being younger was statistically associated with depressive symptoms (p<0.001). CONCLUSIONS In conclusion, based on our findings, fear and depressive symptoms in general population of Bosnia and Herzegovina during the outbreak of COVID-19 were present in 18.06% (fear) and 28.39% (depression) of subjects and it was statistically associated with age, gender, occupation, living environment and may present a secondary uprising problem connected to outbreak of COVID-19.

Aim To investigate the association of ABO blood types and appearance of myocardial infarction (MI) among the population in Bosnia and Herzegovina. Methods This was a cross sectional study conducted at the Department for Cardiovascular Surgery at the Clinical Centre of the University of Sarajevo from January 1st to December 31st 2019. Patients were divided into two groups, defined by their blood type, A (N=91) and non-A (N=109). ABO blood groups were determined using standard agglutination techniques. Information regarding history of MI was taken from their medical documentation during the preparation for surgery. Results In total 200 patients were involved in this study. The study sample consisted of 151 (74.5%) males and 49 (25.5%) females. Mean age was 62.98 ± 7.73. Various risk factors associated with myocardial infarction were tobacco 92 (46.0%) and alcohol 54 (27.0%) consumption, obesity 77 (38.5%), diabetes mellitus 47 (23.5%) and hypertension 91 (45.3%). Being A blood type (OR=3.308; 95% Cl 1.317-8.311; p=0.011) and being male and having hypertension (OR=3.086; 95% Cl 1.262-7.545; p=0.013) significantly increased the risk for the development of MI among young adults. Patients with A blood type were significantly younger [median 58.0 vs. 63.0; U = 2738.5; p =0.027] when they developed MI compared to non-A blood type. Conclusion The age of myocardial infarction occurrence in the population of Bosnia and Herzegovina is lower in patients with blood group A compared to non-A blood types.

Aim To investigate quality of life and exposure to lifestyle risk factors of cancer patients in Bosnia and Herzegovina and a correlation of cancer type with lifestyle risk factors. Methods This was a cross-sectional study conducted on 200 cancer patients from the Clinical Centre of the University of Sarajevo. The respondents completed an anonymous questionnaire consisting of seven sections: basic patient information, physical activity, dietary habits including alternative medicine, tobacco use, alcohol consumption, anxiety, and comorbidities. Results A total of 150 (75%) patients were overweight with 113 (56%) of them being less physically active after the confirmed diagnosis. After the diagnosis, 79 (40%) patients ate less food, and 154 (77%) healthier; 130 (65%) reported consumption of alternative medicine and food supplements, 39 (30%) spent >1/4 of average monthly salary on these products. Majority never consumed alcohol, 135 (68%) and 101 (51%) patients reported history of tobacco use. Being obese was an independent predictor for colorectal carcinoma; being less obese was linked to a decreased risk of breast cancer diagnosis. Physical activity was linked to a decreased risk of lung cancer diagnosis. Many patients (122; 61%) reported having chronic comorbidities, mostly hypertension, while 44 (22%) patients were proven to be clinically anxious. Conclusion Our data suggest lack of public awareness of the consequences of unhealthy lifestyles. Risk factors such as alcohol consumption and tobacco use differed from other European countries. Significance of lifestyle changes after the diagnosis for reducing mortality and cancer recurrence requires further research. Prevention programs and more data are needed.