Das lineare Regressionsmodell von Aalen zur Analyse von Überlebenszeiten unter Berücksichtigung zeitveränderlicher Kovariablen

Data from clinical studies often contain time-dependent covariates, e.g. events like transplantation or an adverse drug reaction, or the changing measurements of laboratory data. The common approach uses only the covariate information at time t=0 for regression analyses, but this baseline analysis is not very satisfying. This paper applies the linear counting process by Aalen for failure time analysis, modified to deal with time-dependent covariates. In the main part we describe methods to estimate and visualize the cumulated regression function with respect to time-dependent covariates. After introducing a test for significance of the influence of covariates we display different methods to investigate model validity depending on martingale residuals, or by use of the Arjas plot. Coding and interpretation problems are shortly discussed. Results are illustrated with data from the Stanford Heart Transplantation Study and a study on Oropharynx carcinoma

Survivalanalysen mit Berücksichtigung der zeitlichen Kovariablenentwicklung in klinischen Studien

Data from the Stanford Heart Transplantation Study and our own study on brain tumor include time-dependent covariates like transplantation, which may switch only once, and others changing their value several times during follow-up. But classical analyses never used this additional information. In a comparative study we applied the time-dependent Cox model, pooled Cox regression and the linear counting process by Aalen to these data sets. All methods do show similar results when they are carried out in their 'fixed' version, i.e. using baseline information only, or when covariates are being treated as time-dependent. But the estimated effects do differ remarkably between fixed and time-dependent approaches, thus leading to different interpretations of risks

Validity and reliability of the Turkish version of DSM-5 level 2 anxiety scale (Child form for 11-17 years and parent form for 6-17 years)

Introduction: This study aimed to assess the validity and reliability of the Turkish Version of DSM-5 Level 2 Anxiety Scale’s child and parent forms. Methods: The scale was constructed by carrying out the translation and back translation of DSM-5 Level 2 Anxiety Scale. The study group consisted of a community and clinical sample. The scale was applied to 148 parents and 189 adolescents that represented the clinical and community sample. During the assessment process, Screen for Childhood Anxiety Related Emotional Disorders and Strengths and Difficulties Questionnaire-Parent Form were also used. Results: Reliability analyses indicated a high internal consistency regarding Level 2 Anxiety Scales, both for child and parent forms (0.915/0.933). In the meantime, it was shown that child form for Level 2 Anxiety Scale was significantly correlated with Screen for Childhood Anxiety Related Emotional Disorders (r=0.758, p<0.0001) while the parent form was significantly correlated with Strengths and Difficulties Questionnaire-Parent Form (r=0.717, p<0.0001). As for the content validity, one factor was obtained for both forms, and it was observed to be consistent with the original construct of the scale. Conclusion: It was concluded that Turkish version of DSM-5 Level 2 Anxiety Scale was a valid and reliable tool to be utilized both for clinical practice, and research purposes. © 2016 by Turkish Association of Neuropsychiatry

Food-induced anaphylaxis in early childhood and factors associated with its severity.

Background: Several factors that increase the risk of severe food-induced anaphylaxis have been identified

Early neonatal outcomes of very-low-birth-weight infants in Turkey: A prospective multicenter study of the Turkish Neonatal Society

Beken, Serdar/0000-0002-8609-2684; BAS, AHMET YAGMUR/0000-0002-1329-2167; Bulbul, Ali/0000-0002-3510-3056; Karatekin, Guner/0000-0001-7112-0323WOS: 000534242500056PubMed: 31851725Objective To investigate the early neonatal outcomes of very-low-birth-weight (VLBW) infants discharged home from neonatal intensive care units (NICUs) in Turkey. Material and methods A prospective cohort study was performed between April 1, 2016 and April 30, 2017. the study included VLBW infants admitted to level III NICUs. Perinatal and neonatal data of all infants born with a birth weight of.1500 g were collected for infants who survived. Results Data from 69 NICUs were obtained. the mean birth weight and gestational age were 1137 +/- 245 g and 29 +/- 2.4 weeks, respectively. During the study period, 78% of VLBW infants survived to discharge and 48% of survived infants had no major neonatal morbidity. VLBW infants who survived were evaluated in terms of major morbidities: bronchopulmonary dysplasia was detected in 23.7% of infants, necrotizing enterocolitis in 9.1%, blood culture proven late-onset sepsis (LOS) in 21.1%, blood culture negative LOS in 21.3%, severe intraventricular hemorrhage in 5.4% and severe retinopathy of prematurity in 11.1%. Hemodynamically significant patent ductus arteriosus was diagnosed in 24.8% of infants. Antenatal steroids were administered to 42.9% of mothers. Conclusion the present investigation is the first multicenter study to include epidemiological information on VLBW infants in Turkey. Morbidity rate in VLBW infants is a serious concern and higher than those in developed countries. Implementation of oxygen therapy with appropriate monitoring, better antenatal and neonatal care and control of sepsis may reduce the prevalence of neonatal morbidities. Therefore, monitoring standards of neonatal care and implementing quality improvement projects across the country are essential for improving neonatal outcomes in Turkish NICUs.Turkish Neonatal Society [2-2016]; Turkish Neonatal SocietyThis study was supported by the Turkish Neonatal Society, http://www.neonatology.org.tr, number 2-2016, received by AYB. Turkish Neonatal Society funded the study's online registry system. the funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript