Arthrography of the knee: a comparative study of the accuracy of single and double contrast techniques

Single and double contrast arthrographic techniques were compared in 951 patinets with suspected meniscal injuries. Exploratory surgery of the knee was performed in 384 of these patients and good clinical follow-up was obtained in 135 patients. In the latter two groups of patients, the single contrast technique was 97% accurate in assessing the medial meniscus and 96% accurate in assessing the lateral meniscus. Double contrast arthrography was 97% accurate in assessing the medial meniscus and 93% accurate in assessing the lateral meniscus. Numerical differences in the results from the two techniques were not statistically significant. Therefore both techniques can be considered equally effective diagnostically.     

Therapeutic misconception in early phase gene transfer trials

Many subjects in early phase clinical trials expect to benefit in some way from the research intervention. It is understandable that people hope for improvement in their condition, no matter what the evidence. Yet unreasonable expectation of medical benefit may reflect problems with informed consent: Investigators may not disclose clearly that direct medical benefit from an early phase experimental intervention is unlikely or impossible, or subjects may not appreciate the differences between treatment and research. This paper presents findings from recent interviews with researchers and subjects and analysis of consent forms in early phase gene transfer research, a cutting-edge technology often called 'gene therapy'. We use three variables to construct a composite measure of therapeutic misconception TM, tapping misconceptions about the purposes of early phase research and the potential for direct medical benefit in these trials. Our multivariate model demonstrates the importance of both subject- and study-level factors as predictors of this TM index: education, disease type, and communication by study personnel about the likelihood of benefit. We hope that this work will deepen the discussion of how to define and measure TM, and refine the specification of factors that are related to subjects' TM.     

An alternative and robust synthesis of [13C4]Baraclude® (entecavir)

Stable isotope‐labeled [¹³C₄]entecavir (1) was prepared in 11 steps. Commercially available [¹³C]guanidine hydrochloride and diethyl[1,2,3‐¹³C₃]malonate were condensed to yield 2‐amino[2,4,5,6‐¹³C₄]pyrimidine‐4,6‐diol (8). This was converted to the desired purine (7) in five steps. Introduction of the chiral epoxide was followed by subsequent deprotection to give [¹³C₄]entecavir (1), in an overall yield of 5.7% from labeled precursors. The chemical purity of the title compound was determined to be >99% by HPLC. The isotopic distribution was determined by mass spectrometry to be 282[M + 4], 98.4%; 281[M + 3], 1.6%; and 278[M + 0], <0.1%. Copyright © 2013 John Wiley & Sons, Ltd.     

Physicians' Assessment of Pediatric Returns to the Emergency Department

Background

Return visits to the Emergency Department (ED) requiring admission are frequently reviewed for the purpose of quality improvement. Treating physicians typically perform this review, but it is unclear if they accurately identify the reasons for the returns.

Objectives

To assess the characteristics of pediatric return visits to the ED, and the ability of treating physicians to identify the root causes for these return visits.

Methods

This retrospective cohort study reviewed all returns within 96 h of an initial visit over a 2-year period at a tertiary care pediatric ED. Baseline characteristics were determined from review of patients' charts. The treating physicians, the primary author, and independent reviewers identified the root cause for the returns.

Results

There were 97,374 patients that presented to the ED during the study, and 1091 (1.1%) of these children returned to the ED and were admitted. Returns were most common among children aged <5 years, arriving between 3:00 p.m. and 11:00 p.m. via private transportation, with infectious diseases. The physician involved in the care of the patient attributed 3.1% of returns to potential deficiencies in medical management, whereas the independent reviewers attributed 13% to potential deficiencies.

Conclusions

Both returns and the subset of returns due to potential deficiencies in management are more common than previously estimated, rendering review of returns a valuable quality improvement tool. However, EDs should not rely exclusively on the treating physicians to identify the reason for returns, as they seem to underestimate the frequency of returns due to potential deficiencies in medical management.     

Evaluation of the role of location and distance in recruitment in respondent-driven sampling

Background

The purpose of the project was to delineate a series of contiguous neighbourhood-based "Data Zones" within the Region of Peel (Ontario) for the purpose of health data analysis and dissemination. Zones were to be built on Census Tracts (N = 205) and obey a series of requirements defined by the Region of Peel. This paper explores a method that combines statistical analysis with ground-truthing, consultation, and the use of a decision tree.

Data

Census Tract data for Peel were derived from the 2006 Canadian Census Master file.

Methods

Following correlation analysis to reduce the data set, Principal Component Analysis was applied to the data set to reduce the complexity and derive an index. The Getis-Ord Gi*statistic was then applied to look for statistically significant clusters of like Census Tracts. A detailed decision tree for the amalgamation of remaining zones and ground-truthing with Peel staff verified the resulting zones.

Results

A total of 15 Data Zones that are similar with respect to socioeconomic and sociodemographic attributes and that met criteria defined by Peel were derived for the region.

Conclusion

The approach used in this analysis, which was bolstered by a series of checks and balances throughout the process, gives statistical validity to the defined zones and resulted in a robust series of Data Zones for use by Peel Public Health. We conclude by offering insight into alternative uses of the methodology, and limitations.     

Experimental studies on red cell-based assays for total IgE and allergen-specific IgE

The potential of red cell-based assays for IgE and allergen-specific IgE has been examined using mouse monoclonal anti-human IgE antibodies and chimaeric human IgE anti-4-hydroxy-3-iodo-5-nitrophenacetyl. Experiments concerned with developing a red cell IgE antibody-capture assay for allergen-specific IgE have pointed to the advantages of presenting the allergen on a second agglutinable red cell.