Effect of choice of reference equation on analysis of pulmonary function in cystic fibrosis patients

Pulmonary function is an important measure of disease severity and prognosis in cystic fibrosis (CF). It is generally expressed as a percentage of a predicted value, calculated using regression equations derived from a reference population. A number of reference equations are in widespread use. The purposes of this study were to determine: 1) the extent to which, for a given absolute FEV(1) value, percent of predicted (PPFEV(1)) values vary when derived by different reference equations; and 2) whether these differences affect conclusions of longitudinal and cross-sectional analyses. Subjects were all Caucasians 6-18 years old in the 1990 Cystic Fibrosis Foundation Registry. We found clinically important discrepancies in PPFEV(1) when calculated by the methods of Dockery et al. [Am Rev Respir Dis 1983;128:405-412] and Wang et al. [Pediatr Pulmonol 1993;15:75-78] as compared to Knudson et al. [Am Rev Respir Dis 1983;127:725-734] or Polgar and Promadhat [Pulmonary Function Testing in Children 1971; Philadelphia: W.B. Saunders]. In longitudinal analyses, the choice of reference equation resulted in varying apparent rates of decline in FEV(1). For example, among subjects ages 12-14 years in 1990, the decline in PPFEV(1) from 1990-1995 varied between 2-11%, depending on the choice of reference equation. In cross-sectional analyses, the choice of reference equation affected the distribution of subjects classified as having mild, moderate, or severe lung disease. CF physicians should be aware of the impact of choice of reference equation in both clinical care and research.     

Multiple cluster analysis for the identification of high-risk census tracts for out-of-hospital cardiac arrest (OHCA) in Denver,Colorado

Background

Prior research has shown that high-risk census tracts for out-of-hospital cardiac arrest (OHCA) can be identified. High-risk neighborhoods are defined as having a high incidence of OHCA and a low prevalence of bystander cardiopulmonary resuscitation (CPR). However, there is no consensus regarding the process for identifying high-risk neighborhoods.

Objective

We propose a novel summary approach to identify high-risk neighborhoods through three separate spatial analysis methods: Empirical Bayes (EB), Local Moran's I (LISA), and Getis Ord Gi* (Gi*) in Denver, Colorado.

Methods

We conducted a secondary analysis of prospectively collected Emergency Medical Services data of OHCA from January 1, 2009 to December 31, 2011 from the City and County of Denver, Colorado. OHCA incidents were restricted to those of cardiac etiology in adults ≥18 years. The OHCA incident locations were geocoded using Centrus. EB smoothed incidence rates were calculated for OHCA using Geoda and LISA and Gi* calculated using ArcGIS 10.

Results

A total of 1102 arrests in 142 census tracts occurred during the study period, with 887 arrests included in the final sample. Maps of clusters of high OHCA incidence were overlaid with maps identifying census tracts in the below the Denver County mean for bystander CPR prevalence. Five census tracts identified were designated as Tier 1 high-risk tracts, while an additional 7 census tracts where designated as Tier 2 high-risk tracts.

Conclusion

This is the first study to use these three spatial cluster analysis methods for the detection of high-risk census tracts. These census tracts are possible sites for targeted community-based interventions to improve both cardiovascular health education and CPR training.     

Recommendations for reporting the results of studies of instrument and scale development and testing

Scales and instruments play an important role in health research and practice. It is important that studies that report on their psychometric properties do so in a way such that readers can understand what was done and what was found. This paper is a guide to writing articles about the development and assessment of these tools. It covers what should be in the abstract and how key words should be chosen. The article then discusses what should be in the main parts of the paper: the introduction, methods, results and discussion. In each of these parts, it suggests the statistical tests that should be used and how to report them. The emphasis throughout the paper is that reliability and validity are not fixed properties of a scale, but depend on an interaction among it, the population being evaluated and the circumstances under which the instrument is administered.     

医学统计学试题库管理系统的研究

阐述了医学统计学试题库管理系统的设计构想和实现方式。通过分析试题、试卷和系统功能需求,设计出系统的功能模块、数据结构和业务流程,并采用VisualBasic6．0开发系统界面、AcCeSs2003建立试题数据库、word2003作为文档输出端。该系统能够有效实现教考分离,使考试更加规范化、科学化。     

PACS服务器日志分析软件的研制

研制PACS服务器日志分析软件ParseLog,实现服务日志的精准高效分析,为日常维护工作提供强有力的分析工具,确保PACS系统的平稳运行.首先分析日志记录的特点,围绕文件传输、记录解析、数据统计等问题,设计了ParseLog软件的功能架构.然后应用Winsock文件传输、Cube多维数据统计、MsChart二维曲线图...     

继续教育医学统计学教学的改革探讨

本文通过分析继续教育医学统计学授课存在的问题,提出在继续教育医学统计学授课中采用PBL教学模式和统计软件辅助教学。结合信息化时代医学统计学的课程特点和PBL教学模式特征,对继续教育医学统计学PBL教学模式的实施方法及统计软件辅助教学的关键点进行探讨。通过PBL教学模式和统计软件的应用提高医学统计学教学效果,有助实现继续教育终身学习的目的 。     

《医学统计学》教学内容与方法的改革与实践

通过一线教学经历,探讨《医学统计学》教学内容与方法改革的实践及效果。在教学中注重教学内容的及时更新与优化、教学方法的改进,教学中采取＂PBL式＂、＂启发式＂、＂形象式＂、＂觅食式＂等多种教学方法综合应用,有助于调动学生学习的积极性和主动性,增强学生分析问题、解决问题的能力,促进教学质量的提高。     

Independence in ROI analysis: where is the voodoo?

We discuss the effects of non-independence on region of interest (ROI) analysis of functional magnetic resonance imaging data, which has recently been raised in a prominent article by Vul et al. We outline the problem of non-independence, and use a previously published dataset to examine the effects of non-independence. These analyses show that very strong correlations (exceeding 0.8) can occur even when the ROI is completely independent of the data being analyzed, suggesting that the claims of Vul et al. regarding the implausibility of these high correlations are incorrect. We conclude with some recommendations to help limit the potential problems caused by non-independence.