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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Guidelines for clinical documentation of evaluation and management face-to-face services were developed > 20 years ago. Recently, the Centers for Medicare & Medicaid Services (CMS) have addressed office and other outpatient services and the corresponding reimbursement, intending to reduce the amount of required documentation and to alleviate clerical burden. A CMS final rule for 2021 will eliminate the history and physical examination as criteria for level of service, allow time or medical decision-making to be used as coding criteria, and will recognize a code for prolonged service. The net effect of these changes may be some decrease in documentation burden, a change in the composition of clinical notes, and greater recognition by CMS of primary care and those who see highly complex patients requiring prolonged services.