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991.
Brown AS Begg MD Gravenstein S Schaefer CA Wyatt RJ Bresnahan M Babulas VP Susser ES 《Archives of general psychiatry》2004,61(8):774-780
CONTEXT: Some, but not all, previous studies suggest that prenatal influenza exposure increases the risk of schizophrenia. These studies used dates of influenza epidemics and maternal recall of infection to define influenza exposure, suggesting that discrepant findings may have resulted from exposure misclassification. OBJECTIVE: To examine whether serologically documented prenatal exposure to influenza increases the risk of schizophrenia. DESIGN: Nested case-control study of a large birth cohort, born from 1959 through 1966, and followed up for psychiatric disorders 30 to 38 years later. SETTING: Population-based birth cohort. PARTICIPANTS: Cases were 64 birth cohort members diagnosed as having schizophrenia spectrum disorders (mostly schizophrenia and schizoaffective disorder). Controls were 125 members of the birth cohort, had not been diagnosed as having a schizophrenia spectrum or major affective disorder, and were matched to cases on date of birth, sex, length of time in the cohort, and availability of maternal serum. MAIN OUTCOME MEASURES: Archived maternal serum was assayed for influenza antibody in pregnancies giving rise to offspring with schizophrenia and matched control offspring. RESULTS: The risk of schizophrenia was increased 7-fold for influenza exposure during the first trimester. There was no increased risk of schizophrenia with influenza during the second or third trimester. With the use of a broader gestational period of influenza exposure-early to midpregnancy-the risk of schizophrenia was increased 3-fold. The findings persisted after adjustment for potential confounders. CONCLUSIONS: These findings represent the first serologic evidence that prenatal influenza plays a role in schizophrenia. If confirmed, the results may have implications for the prevention of schizophrenia and for unraveling pathogenic mechanisms of the disorder. 相似文献
992.
Nietert PJ Silverstein MD Mokhashi MS Kim CY Glenn TF Marsi VA Hawes RH Wallace MB 《Gastrointestinal endoscopy》2003,57(3):311-318
BACKGROUND: Persons with chronic esophageal reflux are at increased risk for the development of Barrett's esophagus and adenocarcinoma. Recently developed ultrathin endoscopes are less expensive and better tolerated than standard endoscopes, they can be used without sedation, and are sensitive and specific for Barrett's esophagus. The cost-effectiveness of one-time screening strategies were evaluated for 50-year-old patients with chronic reflux: no screening, standard endoscopy, and screening by an ultrathin endoscope. METHODS: Markov models were created to simulate the clinical course for patients with chronic reflux. Costs and quality-adjusted life-years were estimated from cancer registry data, published medical data, and expert opinion. RESULTS: Under baseline assumptions, no screening resulted in average costs of $11,785 per person and 19.3226 quality-adjusted life-years. Ultrathin endoscopy screening resulted in costs of $12,119 per person and 19.3326 quality-adjusted life-years, yielding a marginal cost-effectiveness ratio of $55,764 per quality-adjusted life-year. Using standard endoscopy yielded costs of $12,332 with only slightly greater effectiveness, yielding a marginal cost-effectiveness ratio of $709,260 when compared with ultrathin endoscopy and $86,833 compared with no screening. Results were most sensitive to variation in the incidence of cancer in the population with Barrett's esophagus. CONCLUSIONS: Screening for Barrett's esophagus with ultrathin endoscopy is more cost-effective than standard endoscopy, and both strategies appear to improve quality-adjusted life-years among patients with chronic reflux at costs that are similar to those of other accepted preventive measures. 相似文献
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994.
Grey literature in meta-analyses 总被引:4,自引:0,他引:4
BACKGROUND: In meta-analysis, researchers combine the results of individual studies to arrive at cumulative conclusions. Meta-analysts sometimes include "grey literature" in their evidential base, which includes unpublished studies and studies published outside widely available journals. Because grey literature is a source of data that might not employ peer review, critics have questioned the validity of its data and the results of meta-analyses that include it. OBJECTIVE: To examine evidence regarding whether grey literature should be included in meta-analyses and strategies to manage grey literature in quantitative synthesis. METHODS: This article reviews evidence on whether the results of studies published in peer-reviewed journals are representative of results from broader samplings of research on a topic as a rationale for inclusion of grey literature. Strategies to enhance access to grey literature are addressed. RESULTS: The most consistent and robust difference between published and grey literature is that published research is more likely to contain results that are statistically significant. Effect size estimates of published research are about one-third larger than those of unpublished studies. Unfunded and small sample studies are less likely to be published. Yet, importantly, methodological rigor does not differ between published and grey literature. CONCLUSIONS: Meta-analyses that exclude grey literature likely (a) over-represent studies with statistically significant findings, (b) inflate effect size estimates, and (c) provide less precise effect size estimates than meta-analyses including grey literature. Meta-analyses should include grey literature to fully reflect the existing evidential base and should assess the impact of methodological variations through moderator analysis. 相似文献
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997.
Rantz MJ Vogelsmeier A Manion P Minner D Markway B Conn V Aud MA Mehr DR 《The Gerontologist》2003,43(2):248-258
PURPOSE: We describe the development of a statewide strategy to improve resident outcomes in nursing facilities, and we present some evaluative data from this strategy. DESIGN AND METHODS: Key components of the strategy include (a) a partnership between the state agency responsible for the nursing home survey and certification and the school of nursing in an academic health sciences center; and (b) on-site clinical expert technical assistance and support to facilities throughout the state. RESULTS: The partnership has resulted in state agency staff having information from analyses about resident needs and outcomes in the state and facilities having access to the quarterly electronic "Show-Me Quality Indicator Report." On-site clinical expert technical assistance is now used widely across the state, with 569 site visits conducted in 286 different facilities to help them interpret their quality indicator (QI) reports and implement quality improvement programs; statewide improvements in QI scores have been measured in several key QIs. IMPLICATIONS: Other states should consider building partnerships with schools of nursing in an academic health sciences center. Programs using on-site clinical consultation can facilitate improving quality of care in nursing facilities. 相似文献
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Thomas SP Guy DJ Boyd AC Eipper VE Ross DL Chard RB 《The Annals of thoracic surgery》2003,75(2):543-548
BACKGROUND: The optimal technique for producing linear radiofrequency thermal lesions in myocardial tissue is unclear. We compared epicardial ablation on the beating heart with endocardial ablation after cardioplegia. METHODS: Radiofrequency lesions were produced using a multielectrode malleable handheld probe in ovine myocardium with three wall thicknesses. Detailed analysis of lesion dimensions was used to assess the effects of site of ablation, muscle thickness, and duration of ablation. RESULTS: After epicardial atrial ablation, myocardial lesions were detected in all sections without macroscopically visible epicardial fat (n = 10), but only 43% (6/14) of sections with epicardial fat. Three of 24 atrial epicardial sections (13%) and 92% (23/25) of endocardial atrial lesion sections were clearly transmural. In thicker tissues lesion depth was independent of endocardial (right ventricle: 3.9 +/- 1.1 mm, left ventricle: 3.8 +/- 0.7 mm) or epicardial (right ventricle: 3.4 +/- 0.6 mm, left ventricle: 4.3 +/- 0.9 mm) ablation site. Epicardial lesions are less deep in thinner areas of myocardium (p = 0.003). Lesions were all wider than they were deep. There was no significant increase in lesion depth with the increase in ablation duration from 1 to 2 minutes. CONCLUSIONS: Lesions were unlikely to be transmural with either technique when the wall thickness was greater than about 4 mm. Epicardial fat has an important negative effect on epicardial lesion formation. Where epicardial fat is absent epicardially produced lesions penetrate less deeply when the wall thickness is small, possibly due to endocardial cooling by circulating blood. Prolongation of the duration of ablation from 1 to 2 minutes does not significantly increase lesion depth. 相似文献