BACKGROUND AND PURPOSE We verified the propriety of our systematic error reduction strategy by means of a computer simulation based on our data of position error with a prone fixation device for prostate IMRT. MATERIALS AND METHODS Computer simulations of the off-line correction method for systematic setup errors based on the portal imaging taken on the first several days of the treatment ses...

BACKGROUND Questionnaires are used extensively in medical and health care research and depend on validity and reliability. However, participants may differ in interest and awareness throughout long questionnaires, which can affect reliability of their answers. A method is proposed for "screening" of systematic change in random error, which could assess changed reliability of answers. METHODS ...

Geophysical data often contains both systematic and random errors. If left unchecked, the systematic errors can cause acquisition footprint in the final map. I present a method to estimate systematic error by analyzing measurements at points where two acquisition swaths cross. I then subtract the estimated systematic error from the data and generate a map with a familiar least squares formulati...

Taking a falsificationist perspective, the present paper identifies two major shortcomings of existing approaches to comparative model evaluations in general and strategy classifications in particular. These are (1) failure to consider systematic error and (2) neglect of global model fit. Using adherence measures to evaluate competing models implicitly makes the unrealistic assumption that the ...

We report a detailed analysis of the effects of photometric errors in absorption spectroscopy. We show that photometric errors can be divided into five categories, each having a different effect on the relative concentration error for equilibrium and kinetic analyses. Error coefficients defined for each category are incorporated intomathematical equations that permit one to calculate both syste...

Diagnostic test evaluations are susceptible to random and systematic error. Simulated non-differential random error for six different error distributions was evaluated for its effect on measures of diagnostic accuracy for a brucellosis competitive ELISA. Test results were divided into four categories: < 0.25, 0.25-0.349, 0.35-0.499, and > or = 0.50 proportions inhibition for calculation of like...

BACKGROUND It is important for a laboratory to know the stability of performance of laboratory tests over time. The aim of this study was to adapt from the field of clinical chemistry a method to assess the long-term analytical performance of hemostasis field methods. METHODS The linear regression model was used to compare the laboratory results with the consensus mean value of a survey. This...

introduction: medication errors are among the most serious health errors threatening patient safety in all countries, with major impacts on public health. midwives as members of healthcare systems are prone to such errors. therefore, in this study, we aimed to determine medication errors and the contributing factors among midwives working in maternity units of mashhad university of medical scie...