Convergence and divergence: Differences in disability prevalence estimates in the United States and Canada based on four health survey instruments

An analysis of data from the Joint Canada/United States Survey of Health (JCUSH), allows us to compare prevalence estimates that result from four different question sets designed to assess disability from a group of respondents residing in either Canada or the United States. Depending upon the question set used and the coding applied to the responses, age-standardized prevalence estimates varied widely in both countries. In the U.S. noninstitutionalized adult population, disability prevalence estimates ranged from as low as 15.3% to as high as 36.4%, while in Canada the estimates ranged from 13.4% to 37.3%. Concordance and discordance in identification as disabled among these question sets were also examined. In both countries, less than 20% of those identified as disabled by any question set were identified as disabled on all four question sets when using conservative response coding to define disability. Concordance in answers to these questions was also found to be associated with older age, single marital status, low education and low income in both countries. Discordance between question set pairs was similar across both countries whether among measures based on the same domains of disability or different domains of disability. The theory, methods and future of disability measurement in health surveys are discussed in light of these findings. We conclude that understanding and interpreting national prevalence estimates requires more thoughtful attention to the purposes for which data are being collected, the specific definition and operationalizations of disability for those purposes, the methodology used in the data collection and analysis process and the areas of both commonality and difference in the populations identified by each question set. In terms of cross-cultural comparisons, the use of a common set of questions and answer categories and similar survey methodologies provides much more robust results.     

The multiple mini‐interview: how long is long enough?

Objectives  The multiple mini-interview (MMI) overcomes the limitations of the traditional panel interview by multiple sampling to provide improved objectivity and reliability. Reliability of the MMI is affected by number of stations; however, there are few data reporting the influence of interview duration on MMI outcome and reliability. We aimed to determine whether MMI stations can be shortened without affecting applicant rankings or compromising test reliability.
Methods  A total of 175 applicants were interviewed and assessed at 10 8-minute stations. Applicants were scored once after 8 minutes at five control stations and twice after 5 minutes and 8 minutes at five experimental stations. Scores at 5 and 8 minutes were compared using t -tests and correlation coefficients. Rankings of applicants based on 5- and 8-minute scores were compared using Spearman's rank order coefficient. The reliability of the MMI was examined for 5- and 8-minute scores using generalisability theory.
Results  Mean scores at 5 minutes were lower than mean scores at 8 minutes. Cumulative scores at 5 minutes were also lower. There were highly significant correlations between 5- and 8-minute scores at all experimental stations (0.82–0.91; P  < 0.01) and between the cumulative scores at 5 and 8 minutes (0.92; P  < 0.01). There was a strong correlation between applicant rankings based on cumulative 5- and 8-minute scores (Spearman's rank order coefficient 0.92). Reliability was not affected.
Conclusions  Reducing the duration of MMI stations from 8 to 5 minutes conserves resources with minimal effect on applicant ranking and test reliability.     

患者自测腋温在临床运用的研究

目的：了解目前临床上患者自测腋温与护士按教科书规定的规范化测量腋温的测量结果是否有差异,讨论可否将自测腋温应用于临床。方法：对同一患者,在最接近的时问内先后采取让患者自测腋温与护士规范化测量腋温各-次,合计782例,采用统计描述及配对样本t检验的统计方法对结果进行处理。结果：临床患者自测腋温所测得的体温值与护士按教科书规定的规范化测量腋温所测得的体温值差异无统计学意义。结论：临床让患者自测体温的方法具有可行性、实用性。建议将体温测量作为临床护理健康教育内容之一,同时加强临床腋温操作的监督管理。     

科学测量医生工作量

科学测量医生工作量．无论是对于医疗市场的宏观规制还是对于医疗机构内部的微观管理都有着莫大的意义。在分析合理评价医生工作的意义基础上．回顾了国内外测量医生工作量的思路与方法,重点介绍了在此领域有独特建树的哈佛模型。借鉴国际上的成功经验,结合中国国情开发科学测量医生工作量的工具,将有助于中国卫生政策领域实现以数据为基础的循证决策。     

RL_HZJ18型后装机出源长度的测量

目的：测量RL_HZJ18型后装机的出源长度。方法：采用直接测量法和治疗计划法进行测量。结果：两种方法均能测出后装机的出源长度,且能精确到1mm。结论：方法简单、实用、具有可操作性,值得试用和推广。     

基于无线传感网络技术的热解炉温度测量节点设计

目的：介绍一种用于热解炉温度监控的无线传感器网络节点软硬件设计方案。方法：在温度检测电路中,采用芯片MAX6675,简化了系统的软硬件设计,提高了温度检测的精度;无线收发模块采用了芯片CC2420,实现射频通信;采用加州大学伯克利分校开发的TinyOS操作系统节点作为软件平台。结果：完成了一个具备温度数据采集、无线通信和电源能耗管理的无线传感网络节点设计,具有结构简单、体积小、测量准确等特点。结论：该系统有效提高了车载热解炉运行的可靠性,并为无线传感网络技术在卫生技术车辆上的应用打下了基础。     

Functioning and validity of a Computerized Adaptive Test to measure anxiety (A-CAT)

Background: The aim of this study was to evaluate the Computerized Adaptive Test to measure anxiety (A‐CAT), a patient‐reported outcome questionnaire that uses computerized adaptive testing to measure anxiety. Methods: The A‐CAT builds on an item bank of 50 items that has been built using conventional item analyses and item response theory analyses. The A‐CAT was administered on Personal Digital Assistants to n=357 patients diagnosed and treated at the department of Psychosomatic Medicine and Psychotherapy, Charité Berlin, Germany. For validation purposes, two subgroups of patients (n=110 and 125) answered the A‐CAT along with established anxiety and depression questionnaires. Results: The A‐CAT was fast to complete (on average in 2 min, 38 s) and a precise item response theory based CAT score (reliability>.9) could be estimated after 4–41 items. On average, the CAT displayed 6 items (SD=4.2). Convergent validity of the A‐CAT was supported by correlations to existing tools (Hospital Anxiety and Depression Scale‐A, Beck Anxiety Inventory, Berliner Stimmungs‐Fragebogen A/D, and State Trait Anxiety Inventory: r=.56–.66); discriminant validity between diagnostic groups was higher for the A‐CAT than for other anxiety measures. Conclusions: The German A‐CAT is an efficient, reliable, and valid tool for assessing anxiety in patients suffering from anxiety disorders and other conditions with significant potential for initial assessment and long‐term treatment monitoring. Future research directions are to explore content balancing of the item selection algorithm of the CAT, to norm the tool to a healthy sample, and to develop practical cutoff scores. Depression and Anxiety, 2008. © 2008 Wiley‐Liss, Inc.     

Improved fibrinolytic activity during exercise may be an effect of the adipocyte-derived hormones leptin and adiponectin

INTRODUCTION: Physical activity is associated with improved fibrinolytic activity and reduced risk for cardiovascular disease. High levels of leptin and low levels of adiponectin, both adipocyte-derived hormones, or adipokines, are related to dysfibrinolysis and risk for cardiovascular disease. In this study, we explored if improved fibrinolytic activity during exercise could be linked to changes in leptin and adiponectin levels. MATERIALS AND METHODS: Twenty healthy men (mean age 36 years) participated in a 14-day long skiing expedition in the Swedish mountains. They were randomly assigned to either a 40% or a 30% fat-based diet. Anthropometry, lipids, fibrinolytic activity (PAI-1 activity, tPA activity and mass) and adipokines (leptin and adiponectin) were measured before, during and six weeks after the expedition. RESULTS: PAI-1 activity and circulating levels of leptin decreased whereas levels of adiponectin increased during exercise. The fall in PAI-1 activity showed a strong linear association with changes in leptin and adiponectin levels (p=0.001 and p<0.001, respectively). Changes in leptin and adiponectin levels were independent of decreasing waist circumference. However, the association between anthropometric measures and adipokines changed considerably during the expedition. Adiponectin was weakly and negatively associated with BMI at baseline. In contrast, there was a strong positive association between adiponectin and BMI after two weeks of exercise, whereas the association between leptin and BMI became less pronounced. In addition, increasing leptin and decreasing adiponectin levels were associated with increasing PAI-1 activity during the six weeks following the expedition. After six weeks of normal activity, fibrinolytic activity and hormone levels returned towards baseline levels. CONCLUSION: Heavy exercise induced improved fibrinolytic activity, which was associated independently with changes in circulating levels of the adipocyte-derived hormones leptin and adiponectin. Improved fibrinolytic activity (and reduced risk for cardiovascular disease) related to physical activity could possibly be mediated by leptin and adiponectin.     

Construct validity of a 12-item WOMAC for assessment of femoro-acetabular impingement and osteoarthritis of the hip

OBJECTIVE: Evaluation of the internal construct validity of the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index adapted for use in patients with femoro-acetabular impingement (FAI) and osteoarthritis (OA) of the hip. METHODS: Distribution of a German version of WOMAC to patients upon first consultation. Patients with FAI [n=100, mean age 31.7 years, standard deviation (SD) 9.7] and OA (n=57, mean age 60.3 years, SD 11.7) and without comorbidities or prior hip surgery were included and compared to age- and gender-matched control population to FAI (n=200, mean age 32.6 years, SD 5.6). WOMAC data of 157 questionnaires were evaluated by Rasch analysis using RUMM2020 software. RESULTS: Summation of total WOMAC shows misfit to the Rasch model as well as multidimensionality. While the pain subset shows adequate fit and is unidimensional, item reduction is required to fit a unidimensional subset of functional items to the Rasch model. Summating the two fitting subsets yields again slight model misfit and multidimensionality requiring further item reduction. Finally, a 12-item version of the total WOMAC shows good model fit and unidimensionality, i.e., internal construct validity, for assessment of patients with FAI and OA without differential item functioning (DIF). A person separation index (PSI)=0.93 indicates a high internal consistency reliability for the 12-item subscale. Scores for FAI are significantly higher than control (P<0.001, effect size 0.71) and lower than OA group (P<0.001, effect size 0.45). Adequate statistical power is shown discriminating the three groups, therefore indicating some evidence also for external construct validity. CONCLUSIONS: The WOMAC as a total construct is multidimensional and summating the subsets into a total score is not valid. The reduced 12-item WOMAC is demonstrated to have internal construct validity for assessing patients with FAI and OA on the same scale and high internal consistency reliability. Discrimination of the groups with adequate statistical power also indicates external construct validity.