382 research outputs found

    Homocysteine levels and treatment effect in the prospective study of pravastatin in the elderly at risk

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    Objectives: To assess the effect of preventive pravastatin treatment on coronary heart disease (CHD) morbidity and mortality in older persons at risk for cardiovascular disease (CVD), stratified according to plasma levels of homocysteine.<p></p> Design: A post hoc subanalysis in the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), started in 1997, which is a double-blind, randomized, placebo-controlled trial with a mean follow-up of 3.2 years.<p></p> Setting: Primary care setting in two of the three PROSPER study sites (Netherlands and Scotland).<p></p> Participants: Individuals (n = 3,522, aged 70–82, 1,765 male) with a history of or risk factors for CVD were ranked in three groups depending on baseline homocysteine level, sex, and study site.<p></p> Intervention: Pravastatin (40 mg) versus placebo.<p></p> Measurements: Fatal and nonfatal CHD and mortality.<p></p> Results: In the placebo group, participants with a high homocysteine level (n = 588) had a 1.8 higher risk (95% confidence interval (CI) = 1.2–2.5, P = .001) of fatal and nonfatal CHD than those with a low homocysteine level (n = 597). The absolute risk reduction in fatal and nonfatal CHD with pravastatin treatment was 1.6% (95% CI = −1.6 to 4.7%) in the low homocysteine group and 6.7% (95% CI = 2.7–10.7%) in the high homocysteine group (difference 5.2%, 95% CI = 0.11–10.3, P = .046). Therefore, the number needed to treat (NNT) with pravastatin for 3.2 years for benefit related to fatal and nonfatal CHD events was 14.8 (95% CI = 9.3–36.6) for high homocysteine and 64.5 (95% CI = 21.4–∞) for low homocysteine.<p></p> Conclusion: In older persons at risk of CVD, those with high homocysteine are at highest risk for fatal and nonfatal CHD. With pravastatin treatment, this group has the highest absolute risk reduction and the lowest NNT to prevent fatal and nonfatal CHD.<p></p&gt

    'Exacerbation-free time' to assess the impact of exacerbations in patients with chronic obstructive pulmonary disease (COPD):a prospective observational study

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    COPD exacerbations are commonly quantified as rate per year. However, the total amount of time a patient suffers from exacerbations may be stronger related to his or her disease burden than just counting exacerbation episodes. In this study, we examined the relationship between exacerbation frequency and exacerbation-free time, and their associations with baseline characteristics and health-related quality of life. A total of 166 COPD patients reported symptom changes during 12 months. Symptom-defined exacerbation episodes were correlated to the number of exacerbation-free weeks per year. Analysis of covariance was used to examine the effects of baseline characteristics on annual exacerbation frequency and exacerbation-free weeks, Spearman's rank correlations to examine associations between the two methods to express exacerbations and the Chronic Respiratory Questionnaire (CRQ). The correlation between exacerbation frequency and exacerbation-free weeks was -0.71 (p < 0.001). However, among frequent exacerbators (i.e., ≥3 exacerbations/year, n = 113) the correlation was weak (r = -0.25; p < 0.01). Smokers had less exacerbation-free weeks than non-smokers (β = -5.709, p < 0.05). More exacerbation-free weeks were related to better CRQ Total (r = 0.22, p < 0.05), Mastery (r = 0.22, p < 0.05), and Fatigue (r = 0.23, p < 0.05) scores, whereas no significant associations were found between exacerbation frequency and CRQ scores. In COPD patients with frequent exacerbations, there is substantial variation in exacerbation-free time. Exacerbation-free time may better reflect the burden of exacerbations in patients with COPD than exacerbation frequency does

    Genotype versus phenotype in families with androgen insensitivity syndrome

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    Androgen insensitivity syndrome encompasses a wide range of phenotypes, which are caused by numerous different mutations in the AR gene. Detailed information on the genotype/phenotype relationship in androgen insensitivity syndrome is important for sex assignment, treatment of androgen insensitivity syndrome patients, genetic counseling of their families, and insight into the functional domains of the AR. The commonly accepted concept of dependence on fetal androgens of the development of Wolffian ducts was studied in complete androgen insensitivity syndrome (CAIS) patients. In a nationwide survey in The Netherlands, all cases (n = 49) with the presumptive diagnosis androgen insensitivity syndrome known to pediatric endocrinologists and clinical geneticists were studied. After studying the clinical phenotype, mutation analysis and functional analysis of mutant receptors were performed using genital skin fibroblasts and in vitro expression studies. Here we report the findings in families with multiple affected cases. Fifty-nine percent of androgen insensitivity syndrome patients had other affected relatives. A total of 17 families were studied, seven families with CAIS (18 patients), nine families with partial androgen insensitivity (24 patients), and one family with female prepubertal phenotypes (two patients). No phenotypic variation was observed in families with CAIS. However, phenotypic variation was observed in one-third of families with partial androgen insensitivity resulting in different sex of rearing and differences in requirement of reconstructive surgery. Intrafamilial phenotypic variation was observed for mutations R846H, M771I, and deletion of amino acid N682. Four newly identified mutations were found. Follow-up in families with different AR gene mutations provided information on residual androgen action in vivo and the development of the prepubertal and adult phenotype. Patients with a functional complete defective AR had some pubic hair, Tanner stage P2, and vestigial Wolffian duct derivatives despite absence of AR expression. Vaginal length was functional in most but not all CAIS patients. The minimal incidence of androgen insensitivity syndrome in The Netherlands, based on patients with molecular proof of the diagnosis is 1:99,000. Phenotypic variation was absent in families with CAIS, but distinct phenotypic variation was observed relatively frequent in families with partial androgen insensitivity. Molecular observations suggest that phenotypic variation had different etiologies among these families. Sex assignment of patients with partial androgen insensitivity cannot be based on a specific identified AR gene mutation because distinct phenotypic variation in partial androgen insensitivity families is relatively frequent. In genetic counseling of partial androgen insensitivity families, this frequent occurrence of variable expression resulting in differences in sex of rearing and/or requirement of reconstructive surgery is important information. During puberty or normal dose androgen therapy, no or only minimal virilization may occur even in patients with significant (but still deficient) prenatal virilization. Wolffian duct remnants remain detectable but differentiation does not occur in the absence of a functional AR. In many CAIS patients, surgical elongation of the vagina is not indicated

    Chronic non-specific low back pain - sub-groups or a single mechanism?

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    Copyright 2008 Wand and O'Connell; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background: Low back pain is a substantial health problem and has subsequently attracted a considerable amount of research. Clinical trials evaluating the efficacy of a variety of interventions for chronic non-specific low back pain indicate limited effectiveness for most commonly applied interventions and approaches. Discussion: Many clinicians challenge the results of clinical trials as they feel that this lack of effectiveness is at odds with their clinical experience of managing patients with back pain. A common explanation for this discrepancy is the perceived heterogeneity of patients with chronic non-specific low back pain. It is felt that the effects of treatment may be diluted by the application of a single intervention to a complex, heterogeneous group with diverse treatment needs. This argument presupposes that current treatment is effective when applied to the correct patient. An alternative perspective is that the clinical trials are correct and current treatments have limited efficacy. Preoccupation with sub-grouping may stifle engagement with this view and it is important that the sub-grouping paradigm is closely examined. This paper argues that there are numerous problems with the sub-grouping approach and that it may not be an important reason for the disappointing results of clinical trials. We propose instead that current treatment may be ineffective because it has been misdirected. Recent evidence that demonstrates changes within the brain in chronic low back pain sufferers raises the possibility that persistent back pain may be a problem of cortical reorganisation and degeneration. This perspective offers interesting insights into the chronic low back pain experience and suggests alternative models of intervention. Summary: The disappointing results of clinical research are commonly explained by the failure of researchers to adequately attend to sub-grouping of the chronic non-specific low back pain population. Alternatively, current approaches may be ineffective and clinicians and researchers may need to radically rethink the nature of the problem and how it should best be managed

    Identifying factors likely to influence compliance with diagnostic imaging guideline recommendations for spine disorders among chiropractors in North America: a focus group study using the Theoretical Domains Framework

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    Background: The Theoretical Domains Framework (TDF) was developed to investigate determinants of specific clinical behaviors and inform the design of interventions to change professional behavior. This framework was used to explore the beliefs of chiropractors in an American Provider Network and two Canadian provinces about their adherence to evidence-based recommendations for spine radiography for uncomplicated back pain. The primary objective of the study was to identify chiropractors’ beliefs about managing uncomplicated back pain without xrays and to explore barriers and facilitators to implementing evidence-based recommendations on lumbar spine xrays. A secondary objective was to compare chiropractors in the United States and Canada on their beliefs regarding the use of spine x-rays. Methods: Six focus groups exploring beliefs about managing back pain without x-rays were conducted with a purposive sample. The interview guide was based upon the TDF. Focus groups were digitally recorded, transcribed verbatim, and analyzed by two independent assessors using thematic content analysis based on the TDF. Results: Five domains were identified as likely relevant. Key beliefs within these domains included the following: conflicting comments about the potential consequences of not ordering x-rays (risk of missing a pathology, avoiding adverse treatment effects, risks of litigation, determining the treatment plan, and using x-ray-driven techniques contrasted with perceived benefits of minimizing patient radiation exposure and reducing costs; beliefs about consequences); beliefs regarding professional autonomy, professional credibility, lack of standardization, and agreement with guidelines widely varied (social/professional role & identity); the influence of formal training, colleagues, and patients also appeared to be important factors (social influences); conflicting comments regarding levels of confidence and comfort in managing patients without x-rays (belief about capabilities); and guideline awareness and agreements (knowledge). Conclusions: Chiropractors’ use of diagnostic imaging appears to be influenced by a number of factors. Five key domains may be important considering the presence of conflicting beliefs, evidence of strong beliefs likely to impact the behavior of interest, and high frequency of beliefs. The results will inform the development of a theorybased survey to help identify potential targets for behavioral-change strategies

    Effect of erythropoietin levels on mortality in old age: the Leiden 85-plus Study

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    BACKGROUND: The production of erythropoietin is triggered by impaired oxygen delivery to the kidney, either because of anemia or hypoxemia. High erythropoietin levels have been shown to predict the risk of death among patients with chronic heart failure. We investigated the prognostic value of elevated erythropoietin levels on mortality among very elderly people in the general population. METHODS: The Leiden 85-plus Study is a population-based prospective follow-up study involving 599 people aged 85 years in Leiden, the Netherlands, enrolled between September 1997 and September 1999. Erythropoietin levels were determined at age 86. For this analysis, we included 428 participants with a creatinine clearance of at least 30 mL/min. Mortality data, recorded until Feb. 1, 2008, were obtained from the municipal registry. RESULTS: During follow-up, 324 (75.7%) participants died. Compared with participants whose erythropoietin levels were in the lowest tertile (reference group), those whose levels were in the middle tertile had a 25% increased risk of death (hazard ratio [HR] 1.25, 95% confidence interval [CI] 0.95–1.64), and those whose levels were in the highest tertile had a 73% increased risk (HR 1.73, 95% CI 1.32–2.26) (p value for trend < 0.01). The association between erythropoietin levels and mortality remained largely unchanged after we adjusted for sex, creatinine clearance, hemoglobin level, comorbidity, smoking status and C-reactive protein level, and was similar for deaths from cardiovascular and noncardiovascular causes. INTERPRETATION: Among people aged 85 years and older, elevated erythropoietin levels were associated with an increased risk of death, independent of hemoglobin levels

    Time trends in preventive drug treatment after myocardial infarction in older patients

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    Secondary preventive drug treatment in patients aged >= 60 years with a history of myocardial infarction was investigated for age-dependent differences in time trends. Sixteen general practices in the Netherlands participated. Preventive treatment with at least three of four drugs (antithrombotics, statins, beta-blockers, and/or angiotensin-converting enzyme inhibitors) increased significantly over time in all three age strata of older patients. Although the greatest relative increase (2.2 times greater) took place in patients aged >= 80 years, these patients consistently had most room for improvement.Public Health and primary careGeriatrics in primary car

    Continuous quantification of transcription factor dynamics in individual hematopoietic stem and progenitor cells

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    STUDY DESIGN: Systematic review of clinical guidelines. OBJECTIVES: To assess the methodologic quality of existing guidelines for the management of acute low back pain. SUMMARY OF BACKGROUND DATA: Guidelines are playing an increasingly important role in evidence-based practice. After publication of the Quebec Task Force in Canada in 1987 and the Agency for Health Care Policy and Research guidelines in the United States in 1994, guidelines for acute low back pain were developed in many other countries. However, little is known about the methodologic quality of these guidelines. METHODS: Guidelines were selected by electronically searching MEDLINE and the Internet and through personal communication with experts in the field of low back pain research in primary care. The methodologic quality of the guidelines was assessed by two authors independently using the AGREE instrument. RESULTS: A total of 17 guidelines were included. Overall, the quality of reporting of guidelines was disappointing. Most guidelines clearly described the aim of the guideline and its target population, and most guideline development committees were multiprofessional. However, many other methodologic flaws were identified. More than half of the guidelines did not take patients' preferences into account, did not perform a pilot test among target users, did not clearly describe the methods of study identification and selection, did not include an external review, did not provide a procedure for updating, were not supported with tools for application, did not consider potential organizational barriers and cost implications, did not provide criteria for monitoring and audit, did not include recommendations for implementation strategies, and did not adequately record editorial independence and conflict of interest of the members. The diagnostic and therapeutic recommendations of the guidelines were largely similar. CONCLUSIONS: The quality and transparency of the development process and the consistency in the reporting of primary care guidelines for low back pain need to be improved

    Hoe en wanneer herkennen huisartsen SOLK?

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    Huisartsen interpreteren symptomen al vroeg in het consult als somatisch onvoldoende verklaarde lichamelijke klachten (SOLK). Signalen die op SOLK kunnen wijzen zijn de manier waarop de patiënt de symptomen presenteert, symptomen die niet in een specifiek patroon passen en symptoomattributie door de patiënt zelf. De snelheid waarmee huisartsen symptomen als SOLK duiden suggereert dat de niet-analytische redeneerwijze een centrale rol speelt in het denkproces.acceptedVersio
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