Which clinical research questions are the most important?:Development and preliminary validation of the Australia & New Zealand Musculoskeletal (ANZMUSC) Clinical Trials Network Research Question Importance Tool (ANZMUSC-RQIT)

Background and aimsHigh quality clinical research that addresses important questions requires significant resources. In resource-constrained environments, projects will therefore need to be prioritized. The Australia and New Zealand Musculoskeletal (ANZMUSC) Clinical Trials Network aimed to develop a stakeholder-based, transparent, easily implementable tool that provides a score for the 'importance' of a research question which could be used to rank research projects in order of importance.MethodsUsing a mixed-methods, multi-stage approach that included a Delphi survey, consensus workshop, inter-rater reliability testing, validity testing and calibration using a discrete-choice methodology, the Research Question Importance Tool (ANZMUSC-RQIT) was developed. The tool incorporated broad stakeholder opinion, including consumers, at each stage and is designed for scoring by committee consensus.ResultsThe ANZMUSC-RQIT tool consists of 5 dimensions (compared to 6 dimensions for an earlier version of RQIT): (1) extent of stakeholder consensus, (2) social burden of health condition, (3) patient burden of health condition, (4) anticipated effectiveness of proposed intervention, and (5) extent to which health equity is addressed by the research. Each dimension is assessed by defining ordered levels of a relevant attribute and by assigning a score to each level. The scores for the dimensions are then summed to obtain an overall ANZMUSC-RQIT score, which represents the importance of the research question. The result is a score on an interval scale with an arbitrary unit, ranging from 0 (minimal importance) to 1000. The ANZMUSC-RQIT dimensions can be reliably ordered by committee consensus (ICC 0.73-0.93) and the overall score is positively associated with citation count (standardised regression coefficient 0.33, pConclusionWe propose that the ANZMUSC-RQIT is a useful tool for prioritising the importance of a research question

Measurement uncertainty and probability

A measurement result is incomplete without a statement of its 'uncertainty' or 'margin of error'. But what does this statement actually tell us? By examining the practical meaning of probability, this book discusses what is meant by a '95 percent interval of measurement uncertainty', and how such an interval can be calculated. The book argues that the concept of an unknown 'target value' is essential if probability is to be used as a tool for evaluating measurement uncertainty. It uses statistical concepts, such as a conditional confidence interval, to present 'extended' classical methods for evaluating measurement uncertainty. The use of the Monte Carlo principle for the simulation of experiments is described. Useful for researchers and graduate students, the book also discusses other philosophies relating to the evaluation of measurement uncertainty. It employs clear notation and language to avoid the confusion that exists in this controversial field of science.Useful for researchers and graduate students, this book examines the practical meaning of probability."A measurement result is incomplete without a statement of its 'uncertainty' or 'margin of error'. But what does this statement actually tell us? By examining the practical meaning of probability, this book discusses what is meant by a '95 percent interval of measurement uncertainty', and how such an interval can be calculated. The book argues that the concept of an unknown 'target value' is essential if probability is to be used as a tool for evaluating measurement uncertainty. It uses statistical concepts, such as a conditional confidence interval, to present 'extended' classical methods for evaluating measurement uncertainty. The use of the Monte Carlo principle for the simulation of experiments is described. Useful for researchers and graduate students, the book also discusses other philosophies relating to the evaluation of measurement uncertainty. It employs clear notation and language to avoid the confusion that exists in this controversial field of science"-

Estimation of blood flow using Doppler ultrasound with a narrow beam.

Estimation of mean spatial blood velocity, and hence volumetric flow, using Doppler ultrasound is typically performed under the assumption that the beam samples each part of the cross section of the blood vessel equally. This allows the mean velocity to be regarded as being proportional to the conventional mean Doppler shift frequency. In this work a new frequency estimator of mean velocity is presented for the case where the beam is assumed to be of negligible width compared to the vessel diameter and directed through the vessel axis. This estimator is proportional to the mean velocity if it can be further assumed that the velocity profile is axi-symmetric and is monotonic, or has an idealised bidirectional form. In practice neither the assumption of a uniformly insonating beam nor the assumption of an infinitely narrow beam are valid. Also the Doppler spectrum, as a representation of the velocity distribution of blood cells, is corrupted by spectral broadening, noise, filtering and the stochastic nature of the signal. In addition difficulty exists in the measurement of the representative Doppler angle. The effects on both estimators of these potential sources of error are discussed and compared. The question of volumetric flow measurement at various arterial sites is addressed by modelling the velocity profiles in the vessel throughout the cardiac cycle. Some sources of error affect only the new estimator, so one conclusion drawn is that mean velocity estimation and volumetric flow measurement are better performed using the conventional frequency with a uniformly insonating beam. Nevertheless if the beam is more accurately described as being very narrow and centrally positioned the new estimator performs better than the conventional frequency estimator. This description may well be appropriate if the blood vessels are large and the Doppler beam is transmitted and received using a linear array transducer such as in modern duplex systems

Vitamin D, calcium and albumin bloodserum levels in Belgian orthopedic patients – is systematic screening justified?

Introduction: In the setting of fracture care, orthopedic surgeons are primarily focused on treating the fracture itself, but more and more attention is being paid to prevention of such fractures. Materials and methods: We collected postoperative vitamin D, calcium and albumin bloodserum levels from 163 patients who were admitted with a femur fracture and from 233 patients who were admitted for an elective hip arthroplasty during the period of 365 days. Results: 84.21% of the fracture population had a vitamin D deficiency (< 20 ng/mL) as well as 77.30% of the elective hip arthroplasty population. There were no significant seasonal differences in the fracture population. 80.27% of the fracture population had an albumin deficiency (< 29 g/L) and 38.75% of the reference population. There were no significant statistical differences in vitamin D and albumin bloodserum levels in the two age groups. Conclusion: We can make the tentative assumption that systematic screening for all hip fracture patients and all elective hip arthroplasty patients admitted to our orthopedic ward – independent of their age, season or pathology – is justified

Exposure to nitrate and nitrite in drinking water and cancers

Objectives: This is a protocol for a Cochrane Review (prototype). The objectives are as follows:. To assess the association between nitrate and nitrite in drinking water and cancers in observational studies