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At least 433 records · Page 24Linked to original sources

PubMed1999

Is perforation of the appendix a risk factor for tubal infertility and ectopic pregnancy? An appraisal of the evidence.

OBJECTIVE: To critically assess the evidence that appendiceal perforation is a risk factor for subsequent tubal infertility or ectopic pregnancy. DATA SOURCES: Epidemiologic studies investigating the relationship between appendectomy and infertility or ectopic pregnancy were identified by searching the MEDLINE database from 1966 to 1997. Appropriate citations were also extracted from a manual search of the bibliographies of selected papers. STUDY SELECTION: Twenty-three articles were retrieved. Only 4 presented original data including comparisons to a nonexposed control group and they form the basis for this study. DATA EXTRACTION: Because the raw data or specific techniques of data analysis were not always explicitly described, indices of risk for exposure were extracted from the data as presented and were analysed without attempting to convert them to a common measure. DATA SYNTHESIS: Articles were assessed according to the criteria of the Evidence-Based Medicine Working Group for evaluating articles on harm. Review of the literature yielded estimates of the risk of adverse fertility outcomes ranging from 1.6 (95% confidence interval [CI] 1.1 to 2.5) for ectopic pregnancy after an appendectomy to 4.8 (95% CI 1.5 to 14.9) for tubal infertility from perforation of the appendix. Recall bias, and poor adjustment for confounding variables in some reports, weakened the validity of the studies. CONCLUSIONS: The methodologic weaknesses of the studies do not permit acceptance of increased risk of tubal pregnancy or infertility as a consequence of perforation of the appendix, so a causal relationship cannot be supported by the data currently available. Only a well-designed case-control study with unbiased ascertainment of exposure and adjustment for confounding variables will provide a definitive answer.

Appendicitis↗

PubMed2002

Resource use data by patient report or hospital records: do they agree?

BACKGROUND: Economic evaluations alongside clinical trials are becoming increasingly common. Cost data are often collected through the use of postal questionnaires; however, the accuracy of this method is uncertain. We compared postal questionnaires with hospital records for collecting data on physiotherapy service use. METHODS: As part of a randomised trial of orthopaedic medicine compared with orthopaedic surgery we collected physiotherapy use data on a group of patients from retrospective postal questionnaires and from hospital records. RESULTS: 315 patients were referred for physiotherapy. Hospital data on attendances was available for 30% (n = 96), compared with 48% (n = 150) of patients completing questionnaire data (95% Cl for difference = 10% to 24%); 19% (n = 59) had data available from both sources. The two methods produced an intraclass correlation coefficient of 0.54 (95% Cl 0.31 to 0.70). However, the two methods produced significantly different estimates of resource use with patient self report recalling a mean of 1.3 extra visits (95% Cl 0.4 to 2.2) compared with hospital records. CONCLUSIONS: Using questionnaires in this study produced data on a greater number of patients compared with examination of hospital records. However, the two data sources did differ in the quantity of physiotherapy used and this should be taken into account in any analysis.

Adult↗

PubMed1997

Evaluation of validity of British anthropometric reference data for assessing nutritional state of elderly people in Edinburgh: cross sectional study.

OBJECTIVES: To evaluate the appropriateness of two sets of commonly used anthropometric reference data for nutritional assessment of elderly people. DESIGN: Cross sectional study. SETTING: Two general practices in Edinburgh. SUBJECTS: 200 independently living men and women aged 75 or over randomly recruited from the age and sex register of the practices. MAIN OUTCOME MEASURES: Weight (kg), knee height (cm), demispan (cm), mid-upper arm circumference (cm), triceps skinfold thickness (mm), arm muscle circumference (cm) body mass index (kg/m2), and demiquet (kg/m2) in men and mindex (kg/m) in women. RESULTS: Men and women in Edinburgh were significantly shorter than those in measured for the Nottingham reference data (demispan 0.79 v 0.80 (P < 0.05) for men and 0.72 v 0.73 (P < 0.01) for women). Comparison with data from South Wales showed that men and women from Edinburgh had significantly greater mid-upper arm circumference, triceps skinfold thickness, and arm muscle circumference. No one fell below the 10th centile of the South Wales data (the commonly used out off point for determining malnutrition) for these measures. CONCLUSIONS: Both sets of reference data commonly used in Britain may be inappropriate for nutritional screening of elderly people in Edinburgh. Contemporary reference data appropriate for the whole of Britain need to be developed, and in the longer term biologically or clinically defined criteria for undernutrition should be established.

Aged↗

PubMed2006

Strategies to avoid false negative findings in residue analysis using liquid chromatography coupled to time-of-flight mass spectrometry.

Liquid chromatography coupled to orthogonal acceleration time-of-flight mass spectrometry (LC/TOF) provides an attractive alternative to liquid chromatography coupled to triple quadrupole mass spectrometry (LC/MS/MS) in the field of multiresidue analysis. The sensitivity and selectivity of LC/TOF approach those of LC/MS/MS. TOF provides accurate mass information and a significantly higher mass resolution than quadrupole analyzers. The available mass resolution of commercial TOF instruments ranging from 10 000 to 18 000 full width at half maximum (FWHM) is not, however, sufficient to completely exclude the problem of isobaric interferences (co-elution of analyte ions with matrix compounds of very similar mass). Due to the required data storage capacity, TOF raw data is commonly centroided before being electronically stored. However, centroiding can lead to a loss of data quality. The co-elution of a low intensity analyte peak with an isobaric, high intensity matrix compound can cause problems. Some centroiding algorithms might not be capable of deconvoluting such partially merged signals, leading to incorrect centroids.Co-elution of isobaric compounds has been deliberately simulated by injecting diluted binary mixtures of isobaric model substances at various relative intensities. Depending on the mass differences between the two isobaric compounds and the resolution provided by the TOF instrument, significant deviations in exact mass measurements and signal intensities were observed. The extraction of a reconstructed ion chromatogram based on very narrow mass windows can even result in the complete loss of the analyte signal. Guidelines have been proposed to avoid such problems. The use of sub-2 microm HPLC packing materials is recommended to improve chromatographic resolution and to reduce the risk of co-elution. The width of the extraction mass windows for reconstructed ion chromatograms should be defined according to the resolution of the TOF instrument. Alternative approaches include the spiking of the sample with appropriate analyte concentrations. Furthermore, enhanced software, capable of deconvoluting partially merged mass peaks, may become available.

Algorithms↗

PubMedDate not supplied

Using multiple imputation for analysis of incomplete data in clinical research.

BACKGROUND: Sample loss and missing data are inevitable in multivariate and longitudinal research. Ad hoc approaches such as analysis of incomplete data or substituting the group mean for missing data, while common, may unnecessarily reduce statistical power and threaten study validity. Multiple imputation for missing data is a newly accessible, methodologically rigorous approach to dealing with the problem of missing data. APPROACH: To (a) discuss the problem of missing data in clinical research, and (b) describe the technique of multiple imputation. A case of analysis of multivariate psychosocial data is presented to illustrate the practice of multiple imputation. RESULTS: The advantages of multiple imputation are it (a) results in unbiased estimates, providing more validity than ad hoc approaches to missing data; (b) uses all available data, preserving sample size and statistical power; (c) may be used with standard statistical software; and, (d) results are readily interpreted. DISCUSSION: Accessible, user-friendly computer programs are available to perform multiple imputation for missing data making ad hoc approaches to missing data obsolete.

Data Interpretation, Statistical↗

PubMed2005

Genetic analysis of families with autoimmune diabetes and thyroiditis: evidence for common and unique genes.

CONTEXT: Epidemiological data suggest a common genetic susceptibility to type 1 diabetes (T1D) and autoimmune thyroid disease (AITD). OBJECTIVE: Our objective was to identify the joint susceptibility genes for T1D and AITD. DESIGN: We conducted a family-based linkage and association study. SETTING: The study took place at an academic medical center. PARTICIPANTS: Participants included 55 multiplex families (290 individuals) in which T1D and AITD clustered (T1D-AITD families). MAIN OUTCOME MEASURES: We conducted tests for linkage and family-based associations (transmission disequilibrium test) with four candidate genes: human leukocyte antigen (HLA), cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), insulin variable number of tandem repeats (VNTR), and thyroglobulin. RESULTS: Linkage evidence to HLA appeared when subjects with either T1D or AITD were considered affected [maximum LOD score (MLS), 2.2]. The major HLA haplotype contributing to the shared susceptibility was DR3-DQB1*0201, with DR3 conferring most of the shared risk. The CTLA-4 gene showed evidence for linkage only when individuals with both T1D and AITD were considered affected (MLS, 1.7), and the insulin VNTR showed evidence for linkage when individuals with either T1D or AITD were considered affected (MLS, 1.9); i.e. it may contribute to the familial aggregation of T1D and AITD. CONCLUSIONS: The HLA class II locus contributes to the shared risk for T1D and AITD, and the major HLA haplotype contributing to this association is DR3-DQB1*0201. Additional non-HLA loci contribute to the joint susceptibility to T1D and AITD, and two potential candidates include the CTLA-4 and insulin VNTR loci.

Adult↗

PubMed1998

Cerebrospinal fluid syndromes in patients with acute consciousness compromise.

We reviewed the laboratorycards of 200 analysis of cerebrospinal fluid (CSF) performed to evaluate acute alterations of consciousness in adult patients attended in a neurological emergency room. 61% were men; the mean age was 46 years. The most common clinical data were infective and neurologic. The CSF was abnormal in 149 (74.5%) patients and the most common syndromes were: compressive (21%), hemorrhagic (11.5%), "viral" (8.5%), septic (7.5%), moderate hyperglycorrachia (6.5%), hydroelectrolytic disturbances (5.5%). There were some statistically significant correlations between CSF syndromes and clinical data: septic syndrome and fever and meningeal signs, hemorrhagic syndrome and headache and meningeal signs, CSF hydroelectrolytic disturbance syndrome and seizures, severe hyperproteinorrachia and headache, fever, meningeal signs and vomiting, moderate hyperproteinorrachia and age over 65 and male sex. We classified the abnormal results in two groups: 1--sufficient for an immediate clinical decision; 2--nonspecific. The former group was found in 27.5% of the patients and in 36.9% of the abnormal CSF results. In patients attending to neurologic emergency rooms with acute alterations of consciousness, the examination of the CSF frequently could contribute to an etiologic diagnosis. It must be performed after a rigorous clinical evaluation of the patient.

Acute Disease↗

PubMed2004

Nasal decongestants for the common cold.

BACKGROUND: The common cold is a major and recurrent cause of morbidity, affecting children and adults two or more times each year. Nasal congestion is its commonest symptom and many therapies are marketed for its relief. There is no meta-analysis of controlled clinical trials on the effects of nasal decongestants in the common cold. OBJECTIVES: To assess the efficacy of nasal decongestants at reducing the symptom of nasal congestion in adults and children with the common cold and to identify possible adverse effects associated with their use. SEARCH STRATEGY: In updating this review in 2004, the following databases were searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, Issue 1, 2004) which contains the Cochrane Acute Respiratory Infections Group's specialised register; MEDLINE (January 1996 to February week 1 2004); EMBASE (1996 to February week 7 2004); and Current Contents (February 2004). We handsearched review citations from other references and contacted known principal investigators and pharmaceutical companies. SELECTION CRITERIA: Randomised controlled trials with placebo of single-active oral and topical nasal decongestants in adults and children suffering from common cold. DATA COLLECTION AND ANALYSIS: Data were independently extracted by two reviewers (DT and GJL). All outcomes variables were continuous. Subjective outcomes were normalised to a common scale and a weighted mean difference (WMD) was calculated. We calculated a standardised mean difference (SMD) for the objective outcomes. MAIN RESULTS: Five studies involving 286 adults were included, none in children. There was a significant 13% decrease in subjective symptoms after decongestants were compared with placebo. This was supported by a significant decrease in nasal airways resistance. Repeated doses of nasal decongestant were not significantly better than placebo at relieving symptoms of nasal congestion. REVIEWERS' CONCLUSIONS: A single dose of nasal decongestant in the common cold is moderately effective for the short term relief of congestion in adults, while there is no evidence available to show benefit after repeated use over several days. There is insufficient data on the use of these medications in children and therefore they are not recommended for use in young children with the common cold.

Adult↗

PubMed1996

Entry age, entry mode and academic performance on a Project 2000 common foundation programme.

With the increasing academic expectations in the United Kingdom arising from the demands of the recently-introduced Diploma in Higher Education/Registration course (Project 2000) and with fairly substantial proportions of both unqualified (DC test) and mature entrants being admitted onto the course, a study was carried out into the relationship between entry age, entry qualifications and academic performance on the common foundation programme, which lasts for the first 18 months of the course. The entry data and common foundation programme results of each student from the first three intakes, 258 in total, were reviewed. A different subject design was used for the study in which students were placed into one of four groups, according to entry age and entry qualifications, which were: (a) 17-21 conventional entry requirements met; (b) 22 + conventional entry requirements met; (c) 17-21 unqualified (DC test entrant), and (d) 22 + unqualified (DC test entrant). Results indicated that the performance of most mature students, whether qualified or not, was above average, with the qualified group securing the best results of any of the four groups. Among the 17-21 age group, while the qualified performed as expected, the unqualified performed the worst of any of the four groups, registering both a high discontinuation rate and low overall mean scores for the programme. No improvement in the relative performance of the 17-21 unqualified group was noted over the three cohorts and there were indications that under-performance among the unqualified group extended beyond the 17-21 age range. In terms of recruitment, results could indicate a need for a change in policy, with evidence of proven academic ability being required from all younger applicants. If continued recruitment of unqualified younger students is planned, then a more vigorously targeted policy of academic support and guidance for these students will be required. Without this, it seems likely that poor performance and high wastage among this group will continue.

Achievement↗

PubMed2001

Homeless patients' experience of satisfaction with care.

This article explores homeless individuals' experiences of satisfaction with health care, and explores the interrelationship among experiences of being homeless, health perceptions of participants, and experiences of satisfaction with health care. It presents the findings of a phenomenological study that was conducted using participants selected from five sites in one southeastern state. Participant interviews were conducted at a nurse-managed primary health care clinic for homeless, at a night time soup-kitchen, and at three private, not-for-profit, homeless shelters in two different towns. The study was part of a larger study designed to develop and validate a reliable measure of client satisfaction with primary health care among homeless individuals. Face-to-face in-depth interviews with 17 homeless individuals were conducted, with the semistructured interview constituting the primary data source. Common themes were identified and the interrelationship of theme clusters was explored. Analysis of the data yielded five distinct themes that represent the lived experiences of satisfaction with health care. These themes were mediated and directly informed by five themes of homelessness and three themes of health identified in the shared experiences of the participants. The themes identified suggest that satisfaction with health care for homeless persons differs from currently identified dimensions of satisfaction with care, and that some aspects of homelessness are seen by participants as positive and health promoting.

Adult↗

PubMed1995

Lessons learned from a prospective meta-analysis.

OBJECTIVE: To describe the unique aspects of and the lessons learned in planning and conducting a pooled analysis of multiple trials evaluating interventions to reduce functional decline in hospitalized older persons. Specific examples from the Hospital Outcomes Project for the Elderly (HOPE) meta-analysis are discussed. DESIGN: A prospective meta-analysis (PMA) that compiled and pooled data from concurrently conducted clinical trials testing related but distinct interventions. SETTING: The Data Coordinating Center for the prospective meta-analysis coordinated the collection and analysis of common outcome data from five university-affiliated hospitals and one community hospital conducting the clinical trials. PARTICIPANTS: Acutely ill hospitalized elderly participants at least 65 to 75 years old. INTERVENTIONS: Treatments being evaluated included exercise, physical therapy, a multidisciplinary geriatric care unit, a multidisciplinary in-hospital intervention with post-discharge care, a nursing-based geriatric care program, and a program to improve detection and evaluation of delirious patients. CONCLUSION: The prospective meta-analysis provides selected advantages over independently conducted clinical trials and retrospective meta-analyses. It does, however, pose special design and operational challenges that must be addressed well before initiation of the individual trials. Specific issues of concern include: maintaining scientific integrity of both the individual trials and the PMA; reaching consensus on PMA goals, what data to collect, how and when to collect them and how to maintain uniformly high quality data across all sites; defining the role of the Data Coordinating Center in a multicenter project that utilizes different trials and protocols; and establishing policies concerning analyses of the pooled data, publication of pooled analyses, and ownership of the pooled database.

Aged↗

PubMed2002

Chronic cough: evaluation and management.

PURPOSE: To inform the nurse practitioner of the common causes of chronic cough, to educate how each cause can be identified, and to suggest treatment options for the most common causes. DATA SOURCE: Selected research and review articles from professional journals. CONCLUSION: Chronic cough is a common presenting complaint in the primary care setting. Although at first the symptom may seem simple, the etiology, diagnosis, and treatment of chronic cough can be challenging. Furthermore, without proper identification of the cause, effective treatment most likely will not be obtained. IMPLICATIONS FOR PRACTICE: By familiarizing oneself with this topic, nurse practitioners will feel confident in treating chronic cough.

Algorithms↗

PubMedDate not supplied

Effect of operator training on patient exposure: an analysis of the NEXT data.

The Nationwide Evaluation of X-ray Trends (NEXT) program has obtained data from various states on the physical factors related to patient radiation exposure from several common radiographs. Data from two years were examined for exposure, beam area/film area and exposure area product delivered to a "standard patient." The data were examined for differences as a function of operator training.

Humans↗

PubMed1982

Resolution of the multiple inert gas method for estimating VA/Q maldistribution.

During steady-state infusion of a mixture of dissolved inert gases, their elimination by the lung depends on the distribution of ventilation/perfusion (VA/Q) ratios. Thus, certain features of the VA/Q distribution can be inferred from inert gas measurement. Because of the: (1) complexity of the lung, and (2) experimental errors, the ability of such a technique to describe the shape and position of the VA/Q distribution accurately is limited. In this report we present an analysis of the resolution of the method for 9 representative sets of inert gas data, taking account of both of the above factors. These 9 sets span the range of commonly observed data, both in health and in diseases such as asthma, interstitial fibrosis, chronic obstructive lung disease and respiratory distress syndromes. Both error-free and error-containing data are studied and by linear programming methods, bounds are placed on maximum and minimum possible perfusion in several regions of the VA/Q spectrum. Modality is also studied by linear programming. The results show that the resolving power of the method depends greatly on the specific case under study. When groups of units are separated in VA/Q by a decade, this can be determined with considerable confidence. Shunt and low VA/Q areas can generally be well resolved, but when distributions are very broad, resolution is limited.

Aging↗

PubMed2006

An approach based on spatial multicriteria analysis to map the nature conservation value of agricultural land.

Knowledge of the nature conservation value of agricultural land provides a useful input to land-use planning. However, the scarcity of suitable data causes this component to rarely play a role. The paper proposes a methodology based on commonly available data to assess the nature conservation value of agricultural landscapes, and to generate cartographic results to be used as decision variables in planning. The approach relies on landscape ecological indicators and on the application of multicriteria analysis in a Geographical Information System (GIS) context. Four criteria were selected: the agricultural landscape type, the cover of vegetation remnants and marginal features, the length of forest-agriculture ecotones, and the proximity to nature reserves. These criteria were assessed directly or by means of specific indicators, generating maps that were subsequently aggregated through spatial multicriteria analysis. The approach was tested in an alpine area located in Trentino (northern Italy).

Agriculture↗

PubMed1998

Signal timing across the macaque visual system.

The onset latencies of single-unit responses evoked by flashing visual stimuli were measured in the parvocellular (P) and magnocellular (M) layers of the dorsal lateral geniculate nucleus (LGNd) and in cortical visual areas V1, V2, V3, V4, middle temporal area (MT), medial superior temporal area (MST), and in the frontal eye field (FEF) in individual anesthetized monkeys. Identical procedures were carried out to assess latencies in each area, often in the same monkey, thereby permitting direct comparisons of timing across areas. This study presents the visual flash-evoked latencies for cells in areas where such data are common (V1 and V2), and are therefore a good standard, and also in areas where such data are sparse (LGNd M and P layers, MT, V4) or entirely lacking (V3, MST, and FEF in anesthetized preparation). Visual-evoked onset latencies were, on average, 17 ms shorter in the LGNd M layers than in the LGNd P layers. Visual responses occurred in V1 before any other cortical area. The next wave of activation occurred concurrently in areas V3, MT, MST, and FEF. Visual response latencies in areas V2 and V4 were progressively later and more broadly distributed. These differences in the time course of activation across the dorsal and ventral streams provide important temporal constraints on theories of visual processing.

Animals↗

PubMed2006

Discordance between availability of pharmacogenetics studies and pharmacogenetics-based prescribing information for the top 200 drugs.

BACKGROUND: Despite growing numbers of pharmacogenetics studies, little pharmacogenetics-based prescribing information is available to practitioners. It is possible that the lack of prescribing data for commonly used drugs is due to a paucity of evidence-based pharmacogenetics literature for these agents. OBJECTIVE: To investigate the relationship between pharmacogenetics prescribing data in drug package inserts (PIs) and pharmacogenetics research literature for agents represented in the top 200 prescribed drugs for 2003. METHODS: A PubMed search (to August 7, 2004) was performed to identify pharmacogenetics studies relevant to the top 200 drugs. These data were compared with PIs for drugs in the top 200 list that contained pharmacogenetics prescribing information. RESULTS: Pharmacogenetics data in the literature were available for 71.3% of the top 200 drugs. The gene involved coded for a drug-metabolizing enzyme in 34.5% of the literature sampled. The remaining 65.5% of the pharmacogenetics studies contained information largely related to genetic variability in target proteins and drug transporters. Three drugs with PIs containing pharmacogenetics prescribing information deemed to be useful to guide therapy were in the top 200 list (celecoxib, fluoxetine, pantoprazole). There was no consensus on the strength of association between genetic variability and drug response for these agents. CONCLUSIONS: The lack of specific pharmacogenetics-based prescribing information in PIs for commonly used drugs does not seem to be related to a paucity of pharmacogenetics data in the research literature. Rather, other factors including, but not limited to, the uncertain clinical relevance of genetic associations may make practical prescribing recommendations difficult.

Drug Prescriptions↗

PubMed2002

The Bioperl toolkit: Perl modules for the life sciences.

The Bioperl project is an international open-source collaboration of biologists, bioinformaticians, and computer scientists that has evolved over the past 7 yr into the most comprehensive library of Perl modules available for managing and manipulating life-science information. Bioperl provides an easy-to-use, stable, and consistent programming interface for bioinformatics application programmers. The Bioperl modules have been successfully and repeatedly used to reduce otherwise complex tasks to only a few lines of code. The Bioperl object model has been proven to be flexible enough to support enterprise-level applications such as EnsEMBL, while maintaining an easy learning curve for novice Perl programmers. Bioperl is capable of executing analyses and processing results from programs such as BLAST, ClustalW, or the EMBOSS suite. Interoperation with modules written in Python and Java is supported through the evolving BioCORBA bridge. Bioperl provides access to data stores such as GenBank and SwissProt via a flexible series of sequence input/output modules, and to the emerging common sequence data storage format of the Open Bioinformatics Database Access project. This study describes the overall architecture of the toolkit, the problem domains that it addresses, and gives specific examples of how the toolkit can be used to solve common life-sciences problems. We conclude with a discussion of how the open-source nature of the project has contributed to the development effort.

Algorithms↗