SEARCH · PubMed Health

Results for “Methodology”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources

PubMed1994

Using soft systems methodology to develop a simulation of out-patient services.

Discrete event simulation is an approach to modelling a system in the form of a set of mathematical equations and logical relationships, usually used for complex problems, which are difficult to address by using analytical or numerical methods. Managing out-patient services is such a problem. However, simulation is not in itself a systemic approach, in that it provides no methodology by which system boundaries and system activities may be identified. The investigation considers the use of soft systems methodology as an aid to drawing system boundaries and identifying system activities, for the purpose of simulating the outpatients' department at a local hospital. The long term aims are to examine the effects that the participative nature of soft systems methodology has on the acceptability of the simulation model, and to provide analysts and managers with a process that may assist in planning strategies for health care.

Ambulatory Care↗

PubMed2005

Methodological bias in cluster randomised trials.

BACKGROUND: Cluster randomised trials can be susceptible to a range of methodological problems. These problems are not commonly recognised by many researchers. In this paper we discuss the issues that can lead to bias in cluster trials. METHODS: We used a sample of cluster randomised trials from a recent review and from a systematic review of hip protectors. We compared the mean age of participants between intervention groups in a sample of 'good' cluster trials with a sample of potentially biased trials. We also compared the effect sizes, in a funnel plot, between hip protector trials that used individual randomisation compared with those that used cluster randomisation. RESULTS: There is a tendency for cluster trials, with evidence methodological biases, to also show an age imbalance between treatment groups. In a funnel plot we show that all cluster trials show a large positive effect of hip protectors whilst individually randomised trials show a range of positive and negative effects, suggesting that cluster trials may be producing a biased estimate of effect. CONCLUSION: Methodological biases in the design and execution of cluster randomised trials is frequent. Some of these biases associated with the use of cluster designs can be avoided through careful attention to the design of cluster trials. Firstly, if possible, individual allocation should be used. Secondly, if cluster allocation is required, then ideally participants should be identified before random allocation of the clusters. Third, if prior identification is not possible, then an independent recruiter should be used to recruit participants.

Age Factors↗

PubMed2005

Integrating quantitative and qualitative methodologies for the assessment of health care systems: emergency medicine in post-conflict Serbia.

BACKGROUND: Due to the complexity of health system reform in the post-conflict, post-disaster, and development settings, attempts to restructure health services are fraught with pitfalls that are often unanticipated because of inadequate preliminary assessments. Our proposed Integrated Multimodal Assessment - combining quantitative and qualitative methodologies - may provide a more robust mechanism for identifying programmatic priorities and critical barriers for appropriate and sustainable health system interventions. The purpose of this study is to describe this novel multimodal assessment using emergency medicine in post-conflict Serbia as a model. METHODS: Integrated quantitative and qualitative methodologies--system characterization and observation, focus group discussions, free-response questionnaires, and by-person factor analysis--were used to identify needs, problems, and potential barriers to the development of emergency medicine in Serbia. Participants included emergency and pre-hospital personnel from all emergency medical institutions in Belgrade. RESULTS: Demographic data indicate a loosely ordered network of part-time emergency departments supported by 24-hour pre-hospital services and an academic emergency center. Focus groups and questionnaires reveal significant impediments to delivery of care and suggest development priorities. By-person factor analysis subsequently divides respondents into distinctive attitudinal types, compares participant opinions, and identifies programmatic priorities. CONCLUSIONS: By combining quantitative and qualitative methodologies, our Integrated Multimodal Assessment identified critical needs and barriers to emergency medicine development in Serbia and may serve as a model for future health system assessments in post-conflict, post-disaster, and development settings.

Attitude of Health Personnel↗

PubMed2006

Identifying priorities in methodological research using ICD-9-CM and ICD-10 administrative data: report from an international consortium.

BACKGROUND: Health administrative data are frequently used for health services and population health research. Comparative research using these data has been facilitated by the use of a standard system for coding diagnoses, the International Classification of Diseases (ICD). Research using the data must deal with data quality and validity limitations which arise because the data are not created for research purposes. This paper presents a list of high-priority methodological areas for researchers using health administrative data. METHODS: A group of researchers and users of health administrative data from Canada, the United States, Switzerland, Australia, China and the United Kingdom came together in June 2005 in Banff, Canada to discuss and identify high-priority methodological research areas. The generation of ideas for research focussed not only on matters relating to the use of administrative data in health services and population health research, but also on the challenges created in transitioning from ICD-9 to ICD-10. After the brain-storming session, voting took place to rank-order the suggested projects. Participants were asked to rate the importance of each project from 1 (low priority) to 10 (high priority). Average ranks were computed to prioritise the projects. RESULTS: Thirteen potential areas of research were identified, some of which represented preparatory work rather than research per se. The three most highly ranked priorities were the documentation of data fields in each country's hospital administrative data (average score 8.4), the translation of patient safety indicators from ICD-9 to ICD-10 (average score 8.0), and the development and validation of algorithms to verify the logic and internal consistency of coding in hospital abstract data (average score 7.0). CONCLUSION: The group discussions resulted in a list of expert views on critical international priorities for future methodological research relating to health administrative data. The consortium's members welcome contacts from investigators involved in research using health administrative data, especially in cross-jurisdictional collaborative studies or in studies that illustrate the application of ICD-10.

Algorithms↗

PubMed2003

The Aging Males' Symptoms (AMS) scale: review of its methodological characteristics.

BACKGROUND: The current paper reviews data from different sources to get a closer impression on the psychometric and other methodological characteristics of the Aging Males' Symptoms (AMS) scale gathered recently. The scale was designed and standardized as self-administered scale to (a) to assess symptoms of aging (independent from those which are disease-related) between groups of males under different conditions, (b) to evaluate the severity of symptoms over time, and (c) to measure changes pre- and post androgen replacement therapy. The scale is in widespread use (14 languages). METHOD: Original data from different studies in many countries were centrally analysed to evaluate reliability and validity of the AMS. RESULTS: Reliability measures (consistency and test-retest stability) were found to be good across countries, although the sample size was sometimes small. VALIDITY: The internal structure of the AMS in healthy and androgen deficient males, and across countries was sufficiently similar to conclude that the scale really measures the same phenomenon. The sub-scores and total score correlations were high (0.8-0.9) but lower among the sub-scales (0.5-0.7). This however suggests that the subscales are not fully independent. The comparison with other scales for aging males or screening instruments for androgen deficiency showed sufficiently good correlations, illustrating a good criterion-oriented validity. The same is true for the comparison with the generic quality-of-life scale SF36 where also high correlation coefficients have been shown. Methodological analyses of a treatment study of symptomatic males with testosterone demonstrated the ability of the AMS scale to measure treatment effect, irrespective of the severity of complaints before therapy. It was also shown that the AMS result can predict the independently generated (physician's) opinion about the individual treatment effect. CONCLUSION: The currently available methodological evidence points towards a high quality of the AMS scale to measure and to compare HRQoL of aging males over time or before/after treatment, it suggests a high reliability and high validity as far as the process of construct validation could be pressed ahead yet. But certainly more data will become available, particularly from ongoing clinical studies.

Adult↗

PubMed2004

Establishing the scope and methodological approach to out-of-hospital outcomes and effectiveness research.

Outcomes research offers out-of-hospital medicine a valuable methodology for studying the effectiveness of services provided in the out-of hospital setting. A clear understanding of the history and constructs of outcomes research is necessary for its integration into emergency medical services research. This report describes the conceptual framework of outcomes research and key methodological considerations for the successful implementation of out-of-hospital outcomes research. Illustrations of the specific applications of outcomes research and implications to existing methodologies are given, as well as suggestions for improved interdisciplinary research.

Databases as Topic↗

PubMed2003

Health-related quality of life in non-small-cell lung cancer: methodologic issues in randomized controlled trials.

PURPOSE: Non-small-cell lung cancer (NSCLC), a leading cause of cancer-related deaths in both developed and developing countries, heavily impacts patient health-related quality of life (HRQOL). Although recent research has found many positive and significant steps in randomized controlled trials (RCTs) in which HRQOL has been used as an outcome, questions remain regarding methodologic quality and impact value of HRQOL outcome assessments in some RCTs. To date, no detailed systematic review exists of HRQOL methodology in NSCLC RCTs. METHODS: A systematic review using Cochrane methodology evaluated HRQOL components in RCTs. Identified studies were evaluated independently by three reviewers on a broad set of predetermined criteria. RESULTS: Twenty-nine published RCTs (NSCLC patient samples total, N = 8445) with an HRQOL component were identified. Although most trials exhibited good-quality research and useful HRQOL and clinical data, the weaknesses identified in some trials include such common limitations as no clear hypothesis, lack of a clear approach to missing data and data analysis, and limited presentation of results. CONCLUSION: Although it is clear that HRQOL is an important end point in NSCLC RCTs because the information helps to influence treatment recommendations, the identified weaknesses in conducting HRQOL measurement in NSCLC RCTs and the reporting of results need to be addressed.

Carcinoma, Non-Small-Cell Lung↗

PubMed1986

The use of qualitative methodology in child health research.

Qualitative methodology is an appropriate tool for studying children's health care. The present article compares the quantitative and qualitative approaches, describes selected qualitative methodologies, and presents a rational for using these techniques in children's health research. An example is given of a study that combined the two methodologies in order to understand the experiences of well children during routine health care.

Child↗

PubMed1992

Insulin autoantibodies measured by radioimmunoassay methodology are more related to insulin-dependent diabetes mellitus than those measured by enzyme-linked immunosorbent assay: results of the Fourth International Workshop on the Standardization of Insulin Autoantibody Measurement.

Insulin autoantibodies (IAA) have been identified in newly diagnosed insulin-dependent diabetes mellitus (IDDM) patients and in individuals at high risk of developing the disease. However, the literature is not in agreement regarding the prevalence, significance, and predictive value of IAA. Previous workshops have shown that certain sera give markedly different results depending upon assay methodology and, therefore, have suggested that these discrepancies may be due to variations in the assay methodologies used: either the fluid phase RIA or the solid phase enzyme-linked immunosorbent assay (ELISA). Sera from controls (n = 61), newly diagnosed IDDM patients (n = 30), healthy subjects who later became diabetic (n = 8), and first degree relatives of diabetic probands (n = 22) were randomly numbered and sent without category identification to 19 RIA and 10 ELISA laboratories. Each laboratory's raw data from the control sera were used to determine the cut-off point for positive (3 SD above the mean of control sera) in the disease relevant categories. RIA and ELISA methods were comparable in obtaining a low frequency of IAA in control sera. However, the laboratories using RIA methods found a much higher percentage of sera to be IAA positive among both newly diagnosed patients and healthy individuals who later developed diabetes than laboratories using ELISA methods (P less than 0.005). In contrast, there was considerable overlap in the percentage of sera from first degree relatives found positive by both assays. These data strongly suggest that IAA measured by RIA methodology are more disease related than those measured by ELISA methods. Consequently, RIA assays or assays proven to perform as well should be used to measure IAA associated with IDDM.

Autoantibodies↗

PubMed2003

[Synthetic study of biologically important nitrogen containing natural products: development of new methodology and design of leading compounds for new pharmaceuticals].

Synthetic study of biologically important nitrogen-containing natural products and development of new methodologies and design of leading compounds for new pharmaceuticals are described. The first total synthesis of eudistomines, manzamine C, martefragin A, cerebroside B1b, and symbioramide was accomplished and the absolute configurations of the stereogenic centers were determined. A novel methodology useful for the synthesis of alkaloids that have perhydroisoquinoline ring system such as manzamine A and B, and related alkaloids, nakadomarin A and dynemicin A, is presented. Sphingolipids, 4-stereoisomers of 1-phenyl-2-palmitoylamino-3-morpholino-1-propanol, were synthesized and antimalaria activity was investigated. Inhibition of DNA primase by sphingosine and its analogues is described. A new synthetic methodology for alkylation and reduction of imines has been developed, and the first example of a reagent-controlled enantioselective Pictet-Spengler reaction is described. Also novel and convenient methods using transition metal and rare earth metals including alkene metathesis, asymmetric Diels-Alder reaction, imino ene reaction, selective allylic halogenation, enantioselective Pictet-Spengler reaction, and enantioselective physostigmine synthesis are described.

Alkaloids↗

PubMed2006

A systematic review of the methodology of telemedicine evaluation in patients with postural and movement disorders.

We reviewed the methodology used in telemedicine research concerning patients with postural and movement disorders. Literature searches were performed using various computerized databases through to October 2005. Twenty-two studies met the criteria for review. Two broad models of telemedicine delivery were represented in the literature: (1) telemedicine between health-care professionals at each telemedicine site (n=16) and (2) telemedicine between health-care professionals and a patient at a remote site (n=6). Disparate research methodologies were used to investigate these two models. Most studies were limited to investigating the technical feasibility and acceptability of a telemedicine service rather than focusing on the overall effect of introducing the telemedicine service into routine health care. Nonetheless, it is possible to conclude that telemedicine is acceptable for both patients and professionals when used in rehabilitation. Since the two models of telemedicine evaluation tend to explore different outcomes (diagnostic accuracy versus health status), it is recommended that separate methodologies should be used. In contrast to evaluations of telemedicine model 2, randomized controlled trials appear to be less valuable for telemedicine model 1.

Delivery of Health Care↗

PubMed2002

Review article: methodological standards in radiographer plain film reading performance studies.

The objectives of this paper are to raise awareness of the methodological standards that can affect the quality of radiographer plain-film reading performance studies and to determine the frequency with which these standards are fulfilled. Multiple search methods identified 30 such studies from between 1971 and the end of June 1999. The percentage of studies that fulfilled criteria for the 10 methodological standards were as follows. (1) Performance of a sample size calculation, 3%; (2) definition of a normal and abnormal report, 97%; (3) description of the sequence of events through which films passed before reporting, 94%; (4) analysis of individual groups of observers within a combination of groups, 50% (5) appropriate choice of reference standard, 80%; (6) appropriate choice of arbiter, 57%; (7) appropriate use of a control, 22%; (8) analysis of pertinent clinical subgroups, e.g. body areas, patient type, 44%; (9) availability of data for re-calculation, 59%; and (10) presentation of indeterminate results, 69%. These findings indicate variation in the application of the methodological standards to studies of radiographer's film reading performance. Careful consideration of these standards is an essential component of study quality and hence the validity of the evidence base used to underpin radiographic reporting policy.

Clinical Competence↗

PubMed1997

12th meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals: susceptibility to environmental hazards.

The 12th meeting of the Scientific Group on Methodologies for the Safety Evaluation of Chemicals (SGOMSEC) considered the topic of methodologies for determining human and ecosystem susceptibility to environmental hazards. The report prepared at the meeting describes measurement of susceptibility through the use of biological markers of exposure, biological markers of effect, and biomarkers directly indicative of susceptibility of humans or of ecosystems. The utility and validity of these biological markers for the study of susceptibility are evaluated, as are opportunities for developing newer approaches for the study of humans or of ecosystems. For the first time a SGOMSEC workshop also formally considered the issue of ethics in relation to methodology, an issue of particular concern for studies of susceptibility.

Animals↗

PubMed2005

The Oklahoma City bombing study and methodological issues in longitudinal disaster mental health research.

Several methodological issues may affect the findings of studies of the mental health effects of disasters over time. These issues include analysis of the course of individual disorders over time that may be lost when they are presented embedded in general summary statistics, consideration of assessment of psychiatric disorders versus symptoms, adherence to established criteria in assigning psychiatric diagnoses, and orientation of mental health issues to the type of disaster exposure of the sample. This report will explore these methodological issues in a review of disaster literature and in data obtained from study of survivors of the Oklahoma City bombing. Clinical implications of the data obtained from the Oklahoma City bombing study of survivors of the direct bomb blast are presented in the context of these methodological concerns.

Chronic Disease↗

PubMed2005

Opening the black box of stroke rehabilitation with clinical practice improvement methodology.

Although stroke survivors are the largest consumer group for postacute rehabilitation services, there has been little quantification of the details of poststroke rehabilitation (PSR), with the major exception of the AHCPR Clinical Practice Guidelines #16 of 1995. The gold standard research methodology of a randomized controlled trial cannot practically encompass PSR. Using clinical practice improvement (CPI), a statistically based, validated research methodology, a mathematical representation of the inpatient stroke rehabilitation experience has been constructed. This article examines the principle aspects of CPI methodology and how it was adapted to a multicenter study of inpatient PSR.

Evidence-Based Medicine↗

PubMed2002

Methodology to determine duration of action for antihypertensive drugs.

OBJECTIVE: To review and comment on methods used to assess the duration of action of antihypertensive drugs. DATA SOURCES: A MEDLINE search (1966-June 2000) using key terms such as trough-to-peak ratio and ambulatory blood pressure monitoring was conducted. STUDY SELECTION: An article was considered for this review if it pertained to the assessment of the duration of action of antihypertensive drugs. Special attention was given to articles dealing with methodologic aspects. DATA SYNTHESIS: Antihypertensive drugs with a long duration of action are thought to provide better therapeutic coverage against hypertensive complications compared with that of short-acting agents. Measuring blood pressure at the end of the dosing interval may be a way to assess the duration of action of a drug. However, the use of high doses of a short-acting agent to obtain sufficient effect when at trough concentrations can potentially cause dose-related adverse effects at the peak time, contributing to nonadherence to therapy and thus to adverse outcomes. To alleviate this problem, the US Food and Drug Administration (FDA) has conceptualized the trough-to-peak (T:P) ratio. Although this arithmetic index has since been widely used to characterize the duration and safety of blood pressure control achieved by antihypertensive agents, several methodologic flaws limit its interpretation in the clinic. Ambulatory blood pressure monitoring (ABPM) is a more reliable approach to assess the duration of action and outcome of antihypertensive therapy. CONCLUSIONS: Different methodologic approaches exist to evaluate the duration of action of antihypertensive drugs. Although the T:P ratio has been suggested by the FDA, it is difficult to establish a fair comparison among various antihypertensive agents based solely on this index. Treatment evaluation based on ABPM may be preferable to those guided by T:P because ABPM is more reproducible and is now established as a predictor of cardiovascular risk.

Antihypertensive Agents↗

PubMed1999

A critical evaluation of the methodology of the literature on medication compliance.

OBJECTIVE: To develop a simple evaluation tool to assess methodologic rigor of the literature on patient compliance with medications, and to apply the tool to a sample of the literature. METHODS: A computerized search of the MEDLINE database (January 1980-December 1996) was performed. All English-language articles on compliance with medications were identified, using the MeSH terms patient-compliance and drug-therapy. A 10% sample was then randomly selected for review. Methodologic rigor was assessed on eight standards: study design, specification of patient sample, power analysis, specification of disease, specification of therapeutic regimen, duration of follow-up, definition of compliance, and compliance measurement. The raw scores of the eight standards were then combined in three summary scores, standardized from 0 to 100: study design, disease-related features, and compliance issues. RESULTS: Seventy-two articles from 719 identified were reviewed. The majority of the research articles were descriptive (63.9%), and patients in these studies were selected mainly from a convenience sample (41.7%). Just nine studies were multicenter studies, and three employed power analysis. The compliance definition was replicable in 41.7% of the studies. In 22 articles neither the compliance measure nor the criteria were stated. One-quarter of the studies (18) used a nonvalidated measure of compliance. Only two studies reached a score of 6 in the compliance measure, and eight studies used two different measures of compliance simultaneously. The median values in the summary scores were: study design 8.3, disease 42.9, compliance issues 50. CONCLUSIONS: The quality of the compliance research was generally poor. These low scores reflect very important shortcomings in the methodology. Such oversights make it difficult for the reader to critically assess the validity of the conclusions.

Evaluation Studies as Topic↗

PubMed1998

Methodologic standards for diagnostic test research in pulmonary medicine.

STUDY OBJECTIVES: To determine conformance with methodologic standards in the evaluation of diagnostic tests. DATA SOURCES: MEDLINE database search (1992 to 1997) of nine prominent general medicine and six subspecialty journals for articles that report discriminative properties of diagnostic tests in pulmonary medicine. STUDY SELECTION: Articles were eligible if they reported discriminative properties of diagnostic tests in humans, diagnostic tests were intended for the detection of existing conditions, and the target disorder was relevant to pulmonary medicine. DATA EXTRACTION: Each study was critically reviewed independently by two observers. DATA SYNTHESIS: Of the 1,029 retrieved articles, 41 met study inclusion criteria. The median number of the 12 major standards for design fulfilled by study articles was 6 (range, 1 to 12, 25th to 75th percentile, 5.0 to 8.5) and only 2 articles fulfilled all 12 standards. Seven (17%) articles did not report any standard measures of diagnostic accuracy and 7 (17%) provided data only for sensitivity and specificity. Only 4 of 17 articles (24%) that compared different tests used standard statistical methods. CONCLUSION: These results indicate that greater methodologic rigor is needed for studies that evaluate diagnostic tests in pulmonary medicine. Existing deficiencies in methodology risk the introduction of invalid tests into clinical practice.

Area Under Curve↗