Reading a research article part III: the data collection instrument

Parts I through III of this series of articles gave an introduction to some of the issues requiring attention when performing clinical studies and summarizing the results statistically as well as clinically. Statistical methods have been described for the identification of statistically significant differences and associations between an experimental group and a control group or over the course of time after an intervention. The next article will address the methods used for the determination of the strength or magnitude of these identified statistically significant differences.     

Reading statistics in nursing research: a self-study CD-ROM module

A statistics CD-ROM tutorial program was developed to replace a classroom course with several self-study modules. For the CD-ROM delivery method, students were asked to complete a Likert-type questionnaire with response options similar to those used for end-of-course evaluations at the nursing school. Ratings ranged from 1 to 5, with 1 equaling outstanding and 5 equaling completely unsatisfactory. Ratings for the CD-ROM were compared with those of a Web-based course taught the prior year. Mean satisfaction ratings of Web-based delivery of content was low due to technical problems with the Internet courseware used. Overall satisfaction with the CD-ROM for students who used all the components was improved substantially, compared to the Web-based delivery method.     

Mixed-effect statistics for group analysis in fMRI: a nonparametric maximum likelihood approach

This technical note describes a collection of test statistics accounting for estimation uncertainties at the within-subject level, that can be used as alternatives to the standard t statistic in one-sample random-effect analyses, i.e. when testing the mean effect of a population. We build such test statistics by estimating the across-subject distribution of the effects using maximum likelihood under a nonparametric mixed-effect model. For inference purposes, the statistics are calibrated using permutation tests to achieve exact false positive control under a symmetry assumption regarding the across-subject distribution. The new tests are implemented in a freely available toolbox for SPM called Distance.     

Biological parametric mapping with robust and non-parametric statistics

Mapping the quantitative relationship between structure and function in the human brain is an important and challenging problem. Numerous volumetric, surface, regions of interest and voxelwise image processing techniques have been developed to statistically assess potential correlations between imaging and non-imaging metrices. Recently, biological parametric mapping has extended the widely popular statistical parametric mapping approach to enable application of the general linear model to multiple image modalities (both for regressors and regressands) along with scalar valued observations. This approach offers great promise for direct, voxelwise assessment of structural and functional relationships with multiple imaging modalities. However, as presented, the biological parametric mapping approach is not robust to outliers and may lead to invalid inferences (e.g., artifactual low p-values) due to slight mis-registration or variation in anatomy between subjects. To enable widespread application of this approach, we introduce robust regression and non-parametric regression in the neuroimaging context of application of the general linear model. Through simulation and empirical studies, we demonstrate that our robust approach reduces sensitivity to outliers without substantial degradation in power. The robust approach and associated software package provide a reliable way to quantitatively assess voxelwise correlations between structural and functional neuroimaging modalities.     

A comparison of nonparametric and parametric methods to adjust for baseline measures

When analyzing the randomized controlled trial, we may employ various statistical methods to adjust for baseline measures. Depending on the method chosen to adjust for baseline measures, inferential results can vary. We investigate the Type 1 error and statistical power of tests comparing treatment outcomes based on parametric and nonparametic methods. We also explore the increasing levels of correlation between baseline and changes from the baseline, with or without underlying normality. These methods are illustrated and compared via simulations.     

How to read a research article.

Scientific Inquiry provides a forum to facilitate the ongoing process of questioning and evaluating practice, presents informed practice based on available data, and innovates new practices through research and experimental learning.     

A guide to writing and publishing a research article

It is very difficult to write and have own research articles published if there is nothing new to say, if what is written is not stated in a coomprehensive way or if the editorial notes are not strictely followed. The aim of the article is to sustain and encourage first time authors with a guideline to submit their articles. Phases of a research process are compared with the sections of the article providing the explanation of related contents through some practical advices. As an exsample for future Authors, the research article evaluation form used by this journal is reported.     

Reading research critically. II. An introduction to appraisal: assessing the evidence

• ? This is the second of two articles providing an introduction to the critical appraisal of research reports.
• ? In this paper guidelines for evaluating the quality of evidence and the validity of conclusions are suggested, and a check-list of evaluation points is presented.

     

Case managers' roles and functions: Commission for Case Manager Certification's 2004 research, part II

The Commission for Case Manager Certification (CCMC) conducted its third case managers' role and functions study in 2004 for the purpose of validating the currency and relevancy of the certified case manager examination. The results of this study are shared in an article of 2 parts. Part I, which was published in the previous issue of this journal, discussed the process the CCMC used for the development of the Case Managers' Role and Functions Survey Instrument and the identification of new 6 essential functions and 6 knowledge areas that describe case management practice. These findings were based on the survey of a large national sample of practicing case managers. Part II continues the analysis of the results and focuses on identifying the empirical (statistically derived) activity and knowledge domains of case management practice, using exploratory factor analysis. It discusses the similarities and differences found among various subgroups of case managers who were compared on the basis of certain demographic variables. In addition, Part II summarizes future changes in the field of case management as perceived by those who participated in the study.     

Controlled smoking (part II): a last resort

Traditional intervention strategies with smokers have focused on primary prevention programmes (to ‘stop people starting’ and on quit/cessation programmes (to ‘start people stopping’). Although essential elements of a public health policy, prevention and cessation programmes often do not impact on people with chronic highly treatment-resistant smoking behaviours. As one component of a whole health policy, controlled/attenuated smoking progrmmes offer an essential service for smokers who refuse to quit, despite major health problems. ‘Controlled smoking’ is considered to be the reduction of volume intake of cigarettes, achieved via stimulus control of time, place, people or events. Controlled smoking goals typically focus on reductions of 50–80% of original baseline smoking levels, maintained at follow-up.