413 research outputs found

    Minimal changes in health status questionnaires: distinction between minimally detectable change and minimally important change

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    Changes in scores on health status questionnaires are difficult to interpret. Several methods to determine minimally important changes (MICs) have been proposed which can broadly be divided in distribution-based and anchor-based methods. Comparisons of these methods have led to insight into essential differences between these approaches. Some authors have tried to come to a uniform measure for the MIC, such as 0.5 standard deviation and the value of one standard error of measurement (SEM). Others have emphasized the diversity of MIC values, depending on the type of anchor, the definition of minimal importance on the anchor, and characteristics of the disease under study. A closer look makes clear that some distribution-based methods have been merely focused on minimally detectable changes. For assessing minimally important changes, anchor-based methods are preferred, as they include a definition of what is minimally important. Acknowledging the distinction between minimally detectable and minimally important changes is useful, not only to avoid confusion among MIC methods, but also to gain information on two important benchmarks on the scale of a health status measurement instrument. Appreciating the distinction, it becomes possible to judge whether the minimally detectable change of a measurement instrument is sufficiently small to detect minimally important changes

    A comparison of nicotine dose estimates in smokers between filter analysis, salivary cotinine, and urinary excretion of nicotine metabolites

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    RATIONALE: Nicotine uptake during smoking was estimated by either analyzing the metabolites of nicotine in various body fluids or by analyzing filters from smoked cigarettes. However, no comparison of the filter analysis method with body fluid analysis methods has been published. OBJECTIVES: Correlate nicotine uptake estimates between filter analysis, salivary cotinine, and urinary excretion of selected nicotine metabolites to determine the suitability of these methods in estimating nicotine absorption in smokers of filtered cigarettes. MATERIALS AND METHODS: A 5-day clinical study was conducted with 74 smokers who smoked 1–19 mg Federal Trade Commission tar cigarettes, using their own brands ad libitum. Filters were analyzed to estimate the daily mouth exposure of nicotine. Twenty-four-hour urine samples were collected and analyzed for nicotine, cotinine, and 3′-hydroxycotinine plus their glucuronide conjugates. Saliva samples were collected daily for cotinine analysis. RESULTS: Each method correlated significantly (p < 0.01) with the other two. The best correlation was between the mouth exposure of nicotine, as estimated by filter analysis, and urinary nicotine plus metabolites. Multiple regression analysis implies that saliva cotinine and urinary output are dependent on nicotine mouth exposure for multiple days. Creatinine normalization of the urinary metabolites degrades the correlation with mouth exposure. CONCLUSIONS: The filter analysis method was shown to correlate with more traditional methods of estimating nicotine uptake. However, because filter analysis is less complicated and intrusive, subjects can collect samples easily and unsupervised. This should enable improvements in study compliance and future study designs

    Measuring and explaining mortality in Dutch hospitals; The Hospital Standardized Mortality Rate between 2003 and 2005

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    Background. Indicators of hospital quality, such as hospital standardized mortality ratios (HSMR), have been used increasingly to assess and improve hospital quality. Our aim has been to describe and explain variation in new HSMRs for the Netherlands. Methods. HSMRs were estimated using data from the complete population of discharged patients during 2003 to 2005. We used binary logistic regression to indirectly standardize for differences in case-mix. Out of a total of 101 hospitals 89 hospitals remained in our explanatory analysis. In this analysis we explored the association between HSMRs and determinants that can and cannot be influenced by hospitals. For this analysis we used a two-level hierarchical linear regression model to explain variation in yearly HSMRs. Results. The average HSMR decreased yearly with more than eight

    Metabolic profiling of human brain metastases using in vivo proton MR spectroscopy at 3T

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    <p>Abstract</p> <p>Background</p> <p>Metastases to the central nervous system from different primary cancers are an oncologic challenge as the overall prognosis for these patients is generally poor. The incidence of brain metastases varies with type of primary cancer and is probably increasing due to improved therapies of extracranial metastases prolonging patient's overall survival and thereby time for brain metastases to develop. In addition, the greater access to improved neuroimaging techniques can provide earlier diagnosis. The aim of this study was to investigate the feasibility of using proton magnetic resonance spectroscopy (MRS) and multivariate analyses to characterize brain metastases originating from different primary cancers, to assess changes in spectra during radiation treatment and to correlate the spectra to clinical outcome after treatment.</p> <p>Methods</p> <p>Patients (n = 26) with brain metastases were examined using single voxel MRS at a 3T clinical MR system. Five patients were excluded due to poor spectral quality. The spectra were obtained before start (n = 21 patients), immediately after (n = 6 patients) and two months after end of treatment (n = 4 patients). Principal component analysis (PCA) and partial least square regression analysis (PLS) were applied in order to identify clustering of spectra due to origin of metastases and to relate clinical outcome (survival) of the patients to spectral data from the first MR examination.</p> <p>Results</p> <p>The PCA results indicated that brain metastases from primary lung and breast cancer were separated into two clusters, while the metastases from malignant melanomas showed no uniformity. The PLS analysis showed a significant correlation between MR spectral data and survival five months after MRS before start of treatment.</p> <p>Conclusion</p> <p>MRS determined metabolic profiles analysed by PCA and PLS might give valuable clinical information when planning and evaluating the treatment of brain metastases, and also when deciding to terminate further therapies.</p

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Malaysian primary care doctors' views on men's health: an unresolved jigsaw puzzle

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    <p>Abstract</p> <p>Background</p> <p>Men have been noted to utilise health care services less readily then women. Primary care settings provide an opportunity to engage men in health care activities because of close proximity to the target group (men in the community). Understanding attitudes towards men's health among Malaysian primary care doctors is important for the effective delivery of health services to men. We aimed to explore the opinions and attitudes of primary care doctors (PCDs) relating to men's health and help-seeking behaviour.</p> <p>Methods</p> <p>A qualitative approach to explore the opinions of 52 PCDs was employed, using fourteen in-depth interviews and eight focus group discussions in public and private settings. Purposive sampling of PCDs was done to ensure maximum variation in the PCD sample. Interviews were recorded and transcribed verbatim for analysis. Open coding with thematic analysis was used to identify key issues raised in the interview.</p> <p>Results</p> <p>The understanding of the concept of men's health among PCDs was fragmented. Although many PCDs were already managing health conditions relevant and common to men, they were not viewed by PCDs as "men's health". Less attention was paid to men's help-seeking behaviour and their gender roles as a potential determinant of the poor health status of men. There were opposing views about whether men's health should focus on men's <it>overall </it>health or a more focused approach to sexual health. There was also disagreement about whether special attention was warranted for men's health services. Some doctors would prioritise more common conditions such as hypertension, diabetes and hypercholesterolaemia.</p> <p>Conclusions</p> <p>The concept of men's health was new to PCDs in Malaysia. There was wide variation in understanding and opposing attitudes towards men's health among primary care doctors. Creating awareness and having a systematic approach would facilitate PCDs in delivering health service to men.</p

    Mood Induction in Depressive Patients: A Comparative Multidimensional Approach

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    Anhedonia, reduced positive affect and enhanced negative affect are integral characteristics of major depressive disorder (MDD). Emotion dysregulation, e.g. in terms of different emotion processing deficits, has consistently been reported. The aim of the present study was to investigate mood changes in depressive patients using a multidimensional approach for the measurement of emotional reactivity to mood induction procedures. Experimentally, mood states can be altered using various mood induction procedures. The present study aimed at validating two different positive mood induction procedures in patients with MDD and investigating which procedure is more effective and applicable in detecting dysfunctions in MDD. The first procedure relied on the presentation of happy vs. neutral faces, while the second used funny vs. neutral cartoons. Emotional reactivity was assessed in 16 depressed and 16 healthy subjects using self-report measures, measurements of electrodermal activity and standardized analyses of facial responses. Positive mood induction was successful in both procedures according to subjective ratings in patients and controls. In the cartoon condition, however, a discrepancy between reduced facial activity and concurrently enhanced autonomous reactivity was found in patients. Relying on a multidimensional assessment technique, a more comprehensive estimate of dysfunctions in emotional reactivity in MDD was available than by self-report measures alone and this was unsheathed especially by the mood induction procedure relying on cartoons. The divergent facial and autonomic responses in the presence of unaffected subjective reactivity suggest an underlying deficit in the patients' ability to express the felt arousal to funny cartoons. Our results encourage the application of both procedures in functional imaging studies for investigating the neural substrates of emotion dysregulation in MDD patients. Mood induction via cartoons appears to be superior to mood induction via faces and autobiographical material in uncovering specific emotional dysfunctions in MDD
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