Chest
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Retraction Of Publication
Clinical and Genetic Spectrum of Children with Primary Ciliary Dyskinesia in China.
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Cross-sectional studies are observational studies that analyze data from a population at a single point in time. They are often used to measure the prevalence of health outcomes, understand determinants of health, and describe features of a population. Unlike other types of observational studies, cross-sectional studies do not follow individuals up over time. ⋯ They are useful for establishing preliminary evidence in planning a future advanced study. This article reviews the essential characteristics, describes strengths and weaknesses, discusses methodological issues, and gives our recommendations on design and statistical analysis for cross-sectional studies in pulmonary and critical care medicine. A list of considerations for reviewers is also provided.
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Survival (time-to-event) analysis is commonly used in clinical research. Key features of performing a survival analysis include checking proportional hazards assumptions, reporting CIs for hazards ratios and relative risks, graphically displaying the findings, and analyzing with consideration of competing risks. This article provides a brief overview of important statistical considerations for survival analysis. ⋯ Different kinds of bias that influence survival estimation and avenues to model the data under these circumstances are also described. Several analysis techniques are accompanied by graphical representations illustrating proper reporting strategies. We provide a list of guiding statements for researchers and reviewers.
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Sample size determination is an essential step in planning a clinical study. It is critical to understand that different study designs need different methods of sample size estimation. Although there is a vast literature discussing sample size estimation, incorrect or improper formulas continue to be applied. ⋯ To assist clinical researchers in performing sample size calculations, we have developed an online calculator for common clinical study designs. The calculator is available at http://riskcalc.org:3838/samplesize/. Finally, we offer our recommendations on reporting sample size determination in clinical studies.
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Practice Guideline
Managing Chronic Cough as a Symptom in Children and Management Algorithms: CHEST Guideline and Expert Panel Report.
Cough is one of the most common presenting symptoms to general practitioners. The objective of this article is to collate the pediatric components of the CHEST chronic cough guidelines that have recently updated the 2006 guidelines to assist general and specialist medical practitioners in the evaluation and management of children who present with chronic cough. ⋯ The recommendations and suggestions related to the management of chronic cough in the pediatric age group have been based upon high-quality systematic reviews and are summarized in this article. Compared to the 2006 Cough Guidelines, there is now high-quality evidence for some aspects of the management of chronic cough in children. However, further studies particularly in primary health care are required.