200 research outputs found

    Methods for the analysis of ordinal response data in medical image quality assessment.

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    The assessment of image quality in medical imaging often requires observers to rate images for some metric or detectability task. These subjective results are used in optimisation, radiation dose reduction or system comparison studies and may be compared to objective measures from a computer vision algorithm performing the same task. One popular scoring approach is to use a Likert scale, then assign consecutive numbers to the categories. The mean of these response values is then taken and used for comparison with the objective or second subjective response. Agreement is often assessed using correlation coefficients. We highlight a number of weaknesses in this common approach, including inappropriate analyses of ordinal data, and the inability to properly account for correlations caused by repeated images or observers. We suggest alternative data collection and analysis techniques such as amendments to the scale and multilevel proportional odds models. We detail the suitability of each approach depending upon the data structure and demonstrate each method using a medical imaging example. Whilst others have raised some of these issues, we evaluated the entire study from data collection to analysis, suggested sources for software and further reading, and provided a checklist plus flowchart, for use with any ordinal data. We hope that raised awareness of the limitations of the current approaches will encourage greater method consideration and the utilisation of a more appropriate analysis. More accurate comparisons between measures in medical imaging will lead to a more robust contribution to the imaging literature and ultimately improved patient care

    How much information about the benefits of medicines is included in patient leaflets in the European Union? - A survey.

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    INTRODUCTION: Patient information leaflets (PILs) are required with all licensed medicines throughout the European Union (EU) and they must include information about all side effects and their likelihood. This has led to criticism of a lack of balance, with little information included about potential benefits. Recent European Medicines Agency guidance proposed the inclusion of benefit information, and this study examined the current prevalence and type of such information in PILs in the EU. METHODS: A survey and content analysis of the English translation of PILs in the EUwas carried out. Random quota sampling was used on the most frequently dispensed (n = 50) and newly licensed medicines (n = 50) in 2011/2. Leaflets were searched for benefit information meeting predefined criteria, and data synthesised and categorised into 10 categories. RESULTS: Eighty-five (85%) leaflets described how the medicine works, with 45 providing information about the rationale for treatment (more commonly for newly licensed (32/50) than most commonly dispensed medicines (13/50; P < 0.001). Nearly half (47) did not describe whether the medicine was curative, symptomatic or preventative. The terms used to communicate uncertainty were imprecise (such as 'may help'). None communicated numerical benefit information. CONCLUSION: Current PILs do not appropriately communicate information about benefit. At the basic level, around a half did not include information about treatment rationale or whether the treatment was to treat symptoms, curative or preventative. However, for true informed decision making, patients need quantitative information about benefits and none of the leaflets provided this

    Effects of repeated pup exposure on behavioral, neural, and adrenocortical responses to pups in male California mice (Peromyscus californicus)

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    In biparental mammals, the factors facilitating the onset of male parental behavior are not well understood. While hormonal changes in fathers may play a role, prior experience with pups has also been implicated. We evaluated effects of prior exposure to pups on paternal responsiveness in the biparental California mouse (Peromyscus californicus). We analyzed behavioral, neural, and corticosterone responses to pups in adult virgin males that were interacting with a pup for the first time, adult virgin males that had been exposed to pups 3 times for 20min each in the previous week, and new fathers. Control groups of virgins were similarly tested with a novel object (marble). Previous exposure to pups decreased virgins' latency to approach pups and initiate paternal care, and increased time spent in paternal care. Responses to pups did not differ between virgins with repeated exposure to pups and new fathers. In contrast, repeated exposure to a marble had no effects. Neither basal corticosterone levels nor corticosterone levels following acute pup or marble exposure differed among groups. Finally, Fos expression in the medial preoptic area, ventral and dorsal bed nucleus of the stria terminalis was higher following exposure to a pup than to a marble. Fos expression was not, however, affected by previous exposure to these stimuli. These results suggest that previous experience with pups can facilitate the onset of parental behavior in male California mice, similar to findings in female rodents, and that this effect is not associated with a general reduction in neophobia
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