41 research outputs found
Išplėsto dvipakopio klinikinio randomizacijos plano analizė Bajeso metodu.
No full textA. Mainelis.Two-way Enriched Clinical Trial Design in Bayesian Framework: master thesis/ supervisor Assoc. Prof. Dr. V. Skorniakov; Vilnius university, faculty of Mathematics and Informatics, department of Statistical Analysis. The objective of this master thesis is to apply Bayesian methodology to the two-way enriched design (TED) which helps to cope with the high rate of the placebo response. The main part is dedicated to the model parameters estimation using the maximum likelihood (ML) and Bayes approach. For the latter, the informative priors like constrained uniform, beta with appropriate parameters distributions and the objective priors like uniform distributions, Jeffreys, reference were tested. The parameters were estimated on the simulated data. The ML estimates had the lowest bias in almost all the cases, but Bayesian estimates had lower RMSE and Kullback-Leibler divergence in the majority of the configurations. Models with the informative priors showed the best results. In the rest part of this thesis Bayes credible intervals for the hypothesis testing in TED are proposed. The type I error and the power of the new testing procedure were evaluated using the Markov Chain Monte Carlo simulations with the various parameters configurations. The power for testing was higher than in the original approach in almost all the cases. However, type I error rate was controlled well only in the models with the uniform distributions as priors. Using the proposed method in TED, the sample size and the cost of the researches could be reduced. This work could be extend for the continuous outcome in Bayesian framework. Also, the alternative testing procedure might be developed
Sensing the invisible: understanding the perception of indoor air quality among children in low-income families
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On the P-wave model of a single electrocardiogram lead
No full textWe describe a parametric model for the P-wave of a single electrocardiogram (ECG) lead trajectory. Though previously met in the bioengineering literature, the model was not treated in a complete parametric fashion. The paper fills the gap by making use of both frequentist and Bayesian approaches. Supporting real data example is provided. Further potential applications are also discussed
The burden of pediatric atopic dermatitis: quality of life of patients and their families /
No full text(1) Background: Atopic dermatitis (AD) is one of the most common inflammatory skin conditions, thus having a significant impact on the quality of life (QoL) of patients and their families. We performed a survey to gather more data to help describe the burden of AD in Lithuania and to help expand the treatment plan to this important aspect of the disease. (2) Methods: A cross-sectional study was conducted involving healthy and AD pediatric patients. The assessment instruments used were the Patient-Oriented Eczema Measure (POEM), QoL, and original questionnaires (the original questionnaire was designed by the authors to determine the demographics, medical history, and treatment methods of the respondents). (3) Results: This study included 302 participants in total: 247 AD patients (51% boys) and 55 non-AD patients (51% boys). The mean age for AD patients was 6.8 ± 4.4. years, and this was 10.5 ± 3.1 years for the control patients. A significant difference was found between the QoL questionnaire scores and the Family Dermatology Life Quality Index (FDLQI) score for the atopic dermatitis group (QoL: 6.3 ± 5.6; FDLQI: 7.1 ± 6.9) and controls (QoL 0.5 ± 1.1; FDLQI 2.1 ± 5.9) (p = 0.000). The mean QoL questionnaire score for severe AD was 14.3 ± 6.2 (very large effect), that for moderate AD was 6.9 ± 4.4 (moderate effect), and that for mild AD was 4.4 ± 4.2 (small effect) (p = 0.000). (4) Conclusions: Our study revealed a moderate effect of AD on dermatology-related QoL in patients and their families. It has been shown that increased disease severity was associated with a greater impairment of QoL in both patients and patient’s parents. The burden of AD in children and their parents is considerable and should be taken into account in the management of atopic dermatitis
Associations between Atopic Dermatitis and Behavior Difficulties in Children
No full textBackground and Objectives: There has been increasing evidence that atopic dermatitis (AD) is associated with behavioral difficulties (BDs). There is currently a lack of evidence of how the severity of the disease determines BDs and what additional factors may contribute to their manifestation. The aim is to determine what kind of BDs occur in children with AD compared to healthy children and to find out what additional factors may contribute to the development of BDs in AD patients. Materials and Methods: This is a cross-sectional, prospective study with the application of a risk assessment instrument for behavior difficulties (Child Behavior Checklist, CBCL 6/18) in pediatric patients with AD and healthy controls (6–17 years) between 1 January 2020 and 31 December 2022. For statistical comparison, mainly Wilcoxon–Mann–Whitney and Student’s t-test were used, considering a significance level of 5%. Results: This study included a total of 101 children: 48% with AD, 52% non-AD. The mean age was 10 ± 2.7 years for AD, and10.5 ± 3.1 years for the control patients. AD patients had higher internal behavior scale scores and T-scores (6.6 ± 6.4 vs. 9.6 ± 6.9 and 47.9 ± 9.5 vs. 52.3 ± 10.2, p = 0.01), anxiety/depression scale score and T-score (2.8 ± 2.7 vs. 4.3 ± 3.5 and 47.7 ± 8.4 vs. 52.5 ± 11, p = 0.02), and somatic problems scale score and T-score (2.1 ± 2.3 vs. 3.5 ± 3 and 47.6 ± 8.5 vs. 52.7 ± 10.9, p = 0.005). Patients with severe AD had sleep disturbance and itching scores higher than those with mild–moderate AD (5.4 ± 2.6 vs. 2.4 ± 2.2, p = 0.000 and 6.6 ± 2.4 vs. 4 ± 2.8, p = 0.001). The mean morning serum cortisol concentration was lower in AD patients compared to controls (252.91 ± 304.34 vs. 351.55 ± 126.09 nmol/L, p = 0.047). Conclusions: Children with AD present a higher risk of BDs than healthy controls. Patients with severe AD experience more sleep disturbances and a greater intensity of itching compared to mild–moderate AD. The occurrence of BDs was not related to serum cortisol levels. The cortisol level, severity, age, gender, duration of illness, intensity of pruritus, and sleep disturbance did not affect the development of BDs
Comparison of real-time instruments and gravimetric method when measuring particulate matter in a residential building
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The Early Effects on Tricuspid Annulus and Right Chambers Dimensions in Successful Tricuspid Valve Bicuspidization
No full textBackground: It is unclear to what degree of tricuspid annulus (TA) reduction is necessary to achieve good postoperative results in surgical bicuspidization. The study aimed to evaluate TA and right heart chamber’s dimensions before and after heart surgery; and to compare TA parameters assessed by different modalities. Methods: Forty patients underwent mitral valve surgery with or without concomitant tricuspid valve (TV) bicuspidization. Preoperative and postoperative measurements of TA dimensions were performed prospectively using two-dimensional (2D) and three-dimensional (3D) transthoracic echocardiography (TTE). Additionally, preoperative transesophageal echocardiography (TOE) was performed in the operating room prior to surgery. Results: All patients had no or mild TR immediately after surgery. There was a significant reduction in 2D and 3D parameters of the TV and right chambers in the TV bicuspidization group. However, TV leaflets’ tethering parameters did not change significantly. Preoperative 3D TTE measurements were smaller than those obtained through 3D TOE in the operation room, before surgery under general anesthesia. The 2D systolic apical 4Ch diameter and the parasternal short axis diameter mainly represent the 3D minor axis of the TA and are smaller than its 3D major axis. Conclusions: Although bicuspidization results in a one-third reduction of the TV area, tethering of the TV leaflets remains unchanged. Moreover, 3D TOE parameters of the TV under general anesthesia are larger than preoperative 3D TTE measurements. Conventional 2D measurements are insufficient for evaluating the maximum diameter of the TA
Three-dimensional analysis of the tricuspid annular geometry in healthy subjects and in patients with different grades of functional tricuspid regurgitation
No full textAbstract Background Accurate sizing of the tricuspid valve annulus is essential for determining the optimal timing of tricuspid valve (TV) intervention. Two-dimensional (2D) echocardiography has limitations for comprehensive TV analysis. Three-dimensional (3D) imaging of the valve provides a better understanding of its spatial anatomy and enables more accurate measurements of TV structures. Objectives The study aimed to analyze tricuspid annulus (TA) parameters in normal heart and in different grades of functional tricuspid regurgitation (TR); to compare TA measurements obtained by 2D and 3D echocardiography. Methods One hundred fifty-five patients (median age 65 years, 57% women) with normal TV and different functional TR grades underwent 2D and 3D transthoracic echocardiography. The severity of TR was estimated using multiparametric assessment according to the guidelines. Mid-systolic 3D TA parameters were calculated using TV dedicated software. The conventional 2D systolic TA measurements in a standard four-chamber view were performed. Results In mid-systole, the normal TA area was 9.2 ± 2.0 cm2 for men and 7.4 ± 1.6 cm2 for women. When indexed to body surface area (BSA), there were no significant differences in the 3D parameters between genders. The 2D TA diameters were smaller than those measured in 3D. The ROC curve analysis identified that all 3D TA parameters can accurately differentiate between different functional TR grades. Additionally, the optimal cut-off values were identified for each TA parameter. Conclusions Gender, body size, and age have an impact on the TA parameters in healthy subjects. 2D measurements are smaller than 3D parameters. The reference values for 3D metrics according to TR severity can help in identifying TA dilation and distinguishing between different functional TR grades. Graphical Abstrac
Age as a risk factor in the occurrence of complications during or after bronchoscopic lung biopsy /
No full textIntroduction: Bronchoscopic lung biopsy (BLB) is a widely used procedure. As the world’s population is ageing, more BLBs are performed for older people with comorbidities. The aim of the study was to investigate if an older age is a risk factor for BLB related complications. Materials and Methods: A prospective study at the Centre of Pulmonology and Allergology of Vilnius University Hospital Santaros klinikos was conducted. Seven hundred and eighty-six patients (male 60.6%), mean age 57 ± 16, who underwent BLB, were included. The complications that occurred due to BLB were evaluated. Bleeding and pneumothorax were classified into I° or II° grades depending on their severity. Potential determinants, which may increase the risk of complications, emphasizing on age, were analyzed. Results: Fifty-seven (7.2%) BLB-related complications occurred. There were 27 (3.4%) pneumothoraxes, and 19 (70%) of them required thoracic drainage. Thirty (3.8%) bleeding complications occurred, and four (16%) of them were severe. Higher rates of bleeding were found in the age group ≥65 years, p = 0.001. The risk of bleeding in older patients was 3.2 times higher (95% CI 1.51–6.87). Conclusions: Older age is related to a higher incidence of mild bleeding during BLB. However, the risk of life-threatening complications is low despite the age, and older age should not be considered as a contraindication for the procedure if needed
Airborne particulate matter in two multi-family green buildings: concentrations and effect of ventilation and occupant behavior
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