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At least 379 records · Page 21Linked to original sources

PubMed2003

Assessing the methodological quality of nonrandomized intervention studies.

In many areas of health care, randomized controlled trials (the best evidence regarding the effectiveness of health care interventions) are lacking and decision-makers have to rely on evidence from nonrandomized studies (NRS). We conducted a Medline search to identify English-language articles describing instruments for assessing the quality of NRS of health care interventions. These instruments varied greatly in scope, in the number and types of items and in developmental rigor. Items commonly included were those related to specification of study questions, allocation method, comparability of groups, and blinding of outcome assessment. We do not support the development of a generic scale to evaluate the methodological quality of nonrandomized intervention studies. Instead, further study should be directed to investigate the degree to which, and the circumstances under which, different methodological characteristics are associated with bias. This information will assist researchers in identifying a priori which methodological characteristics need careful evaluation in particular studies.

Clinical Trials as Topic↗

PubMed2004

Mixed methods, mixed methodology health services research in practice.

Mixed methods, mixed methodology research is a little documented but increasingly accepted approach employed to investigate organizational phenomena. The author presents a synthesis of literature that informed the decision to adopt a mixed methods, mixed methodology, dominantly naturalistic study approach to health services research in which she explored the process and organizational consequences of new artifact adoption in surgery. She describes the way whereby a collective case study involving five Australian hospitals yielded quantitative and qualitative data that were analyzed using inductive and/or deductive reasoning. She goes beyond the theoretical rational for employing a mixed methods, mixed methodology approach to present a summative conceptual model of the research process and describe the structural aspects of the dissertation in which the research was reported that should benefit researchers contemplating the value of such an approach.

Data Collection↗

PubMedDate not supplied

Qualitative research: methodologies and use in pediatric nursing.

With the increasing number of qualitative research studies being published in nursing journals, pediatric nurses need to understand the different qualitative research methodologies in order to adequately critique these studies and utilize the findings in their clinical practice. Three of the most prominent methodologies in qualitative research are discussed: phenomenology, ethnography, and grounded theory. Examples of published qualitative research in pediatric nursing are described to illustrate each of the three methodologies.

Humans↗

PubMed2005

Methodology is more than research design and technology.

The Society for Computers in Psychology has been at the forefront of disseminating information about advances in computer technology and their applications for psychologists. Although technological advances, as well as clean research designs, are key contributors to progress in psychological research, the justification of methodological rules for interpreting data and making theory choices is at least as important. Historically, methodological beliefs and practices have been justified through intuition and logic, an approach known as foundationism. However, naturalism, a modern approach in the philosophy of science inspired by the work of Thomas S. Kuhn, indicates that all aspects of scientific practice, including its methodology, should be evaluated empirically. This article examines implications of the naturalistic approach for psychological research methods in general and for the current debate that is often framed as one of qualitative versus quantitative methods.

Computers↗

PubMed2002

Making sense of methodologies: a paradigm framework for the novice researcher.

Methodologies abound in the field of health and social science research, making a confusing terrain for new researchers. In this article, we offer order out of confusion. Drawing on our work as postgraduate teachers, we outline a paradigm framework which proposes that methodologies are similar or different because of their underlying assumptions and values. We identify four major paradigms, explain the distinctive assumptions which underpin them, and show how each figures the researcher and the researcher-researched relationship. Along the way, we place a variety of methodologies into their paradigm of origin and offer some illustrative examples of health research.

Bias↗

PubMed2002

The whole story: towards an ethical research methodology.

In this paper Alex Carson and Gavin Fairbairn argue that closer links between nursing education, research and practice may be developed through the use of a narrative methodology. The debate is cited in the wider practical and political context of a more democratic model of healthcare delivery. The authors provide a rationale for the use of stories in both nursing research and nursing practice by suggesting that each rests upon an ethic of helping whole people, rather than simply amounting to a technical undertaking. They suggest that the relationship between the ethical and the technical should be a more explicit feature in discussions of methodological issues in nursing research. They locate ideas about narrative research outside both qualitative and quantitative paradigms. Finally, they offer a philosophical and methodological argument for the use of narratives as an approach to research in which respect for people is central.

Clinical Competence↗

PubMed1997

Strategies to address the methodological challenges of client-satisfaction research in home care.

While there is an abundance of recent client satisfaction research, methodological difficulties continue. This paper addresses common methodological challenges in securing useful feedback from elderly clients receiving home-care services. The methodological challenges include socially desirable response sets (SDRS), fear of reprisal, acquiescent response sets (ARS), and negative or positive wording of items. These contribute to an inability to capture salient dimensions of satisfaction and dissatisfaction important to home-care clients. Several data-collection strategies are proposed: guided interactive interviews, story-telling, scenarios, and rating of the importance of the dimensions of satisfaction and dissatisfaction identified from interview data. Each strategy is discussed using illustrations from a study on elderly clients' satisfaction with home-care services. Nurses and other health-care providers require credible feedback about client satisfaction in order to develop policy and to provide more appropriate and effective services to home-care clients.

Home Care Services↗

PubMedDate not supplied

Methodological advances and plans for improving regulatory success for confirmatory studies.

Regulatory success for new medical products requires convincing statistical results from planned analyses for relevant and reliable data from well-designed clinical studies. Statistical methodology has a critical role for such success through strengthening the robustness of study findings to sources of bias, variability and spurious events. Areas of particular importance for statistical methodology include the structure for study design, the schedule and procedures for data collection, and plans for primary data analyses. This paper discusses some challenging statistical issues for these areas and suggests potential strategies for addressing them. The objective of these strategies as well as other methodological advances is the minimization of ambiguity in the findings of confirmatory studies. In this way, their effective use can enhance regulatory success.

Bias↗

PubMed1998

Methodological considerations for the accurate determination of lead in human plasma and serum.

Studies which accurately measure plasma or serum lead (Pb) are needed to evaluate the 'biologically active' fraction of Pb in the circulation, and to clarify the role of plasma in the transportation of Pb between different compartments of the body. We evaluated several methodological aspects which influence the determination of Pb in plasma and serum. Generally, venous blood was obtained by different sampling methods (routine and ultraclean) from 3 subjects without history of Pb exposure. After centrifugation (800 g) for 10 min, the plasma or serum was analyzed by inductively coupled plasma-high-resolution mass spectrometry (ICP-MS). Several evaluations were conducted, including 1) comparison of an ultraclean serum collection method with a plasma collection method that used a commercial Vacutainer-type tube for trace metals (EDTA anticoagulant); 2) the effect of whole blood standing time prior to centrifugation on plasma or serum Pb concentration; and 3) comparison of a method using commercial heparinized Vacutainer tubes to an ultraclean plasma sampling method that utilized a low-Pb heparin anticoagulant. Plasma or serum iron (Fe) levels were also measured to evaluate hemolysis. The 3 subjects had whole blood Pb (blood-Pb) levels of 1.8, 2.0, and 2.7 micrograms/dl. Their corresponding ultraclean serum-Pb levels were 0.40%, 0.30%, and 0.48% of their whole blood-Pb levels, respectively. By comparison, the EDTA Vacutainer method plasma-Pb values were 1.7%, 1.5%, and 2.4% of whole blood-Pb, respectively. Whole blood standing (clotting) times of 15, 40, and 70 min before centrifugation resulted in increasing ultraclean serum-Pb levels of 0.21%, 0.81%, and 1.2% of whole blood-Pb (1.8 micrograms/dl), respectively. Whole blood standing time had no effect on plasma-Pb levels when heparin Vacutainers were used, or when a low-Pb heparin was used to obtain ultraclean plasma. However, plasma collected using the commercial heparin Vacutainer method contained consistently higher and more variable Pb levels than samples collected using the ultraclean plasma-Pb method. Hemolysis, when present, contributed significantly to both plasma-Pb and serum-Pb levels. In conclusion, plasma-Pb and serum-Pb levels are dependent upon methodologic processing techniques, including Pb contamination control, redistribution due to EDTA anticoagulant, hemolysis, and time dependency in sample processing. While true plasma-Pb and serum-Pb levels by any method have yet to be defined, these data provide a methodological basis from which to investigate variation in Pb partitioning between whole blood and plasma within individuals.

Adult↗

PubMed2000

The polymerase inhibition assay: A methodology for the identification of DNA-damaging agents.

We report here the development of the polymerase inhibition assay (PI assay), a methodology capable of simultaneously identifying multiple DNA-damaging agents. The PI assay was developed in order to fulfil a requirement for the screening of new pharmaceuticals for potential DNA-damaging effects. The assay has the potential to screen hundreds of new compounds per week because of the microtiter plate format employed. We review previous descriptions of the phenomenon and provide researchers with the necessary methodology to obtain optimum polymerase inhibition effects. The assay is based on the inhibition of DNA polymerases (including those used in the polymerase chain reaction (PCR)) encountering damaged DNA bases. Hence, DNA-damaging agents can be identified by a corresponding reduction in PCR amplification after exposure. We demonstrate the detection of polymerase inhibition induced by a range of model genotoxic agents (N-methyl-N-nitrosourea, N-ethyl-N-nitrosourea, and ultraviolet (UV) C radiation), illustrating the successful application of the methodology. In addition, the PI assay is shown to be capable of detecting DNA damaging agents of biological relevance, i.e., known human carcinogens. These were N-OH-PhIP (from cooked meat) and UV-B (from sunlight). In addition to its employment in the detection of putative DNA damaging agents, the PI assay may also be applied as a research tool in carcinogenicity studies.

Base Sequence↗

PubMed1990

Methodological variations in the use of the MMPI for diagnosis of borderline personality disorder among alcoholics.

Methodological variations in the scoring and interpretation of the MMPI and their effects on discrimination between borderline and non-borderline personality disordered alcoholics were investigated. Subjects were 49 male and female inpatient alcoholics in an Icelandic psychiatric hospital. Gunderson's Diagnostic Interview for Borderlines and the Michigan Alcoholism Screening Test were used to diagnose borderline personality disorder and alcoholism, respectively. Scoring and interpretation of the MMPI were varied in terms of the use and non-use of high F-scale profiles, and their impact on the frequency of various code types among borderline and non-borderline personality disordered alcoholics was considered. It was found that such methodological variations do not affect the frequency of some profile types, and, consequently, the discrimination between the diagnostic groups. Studies and coding systems should consider methodological variations in the scoring and interpretation of MMPI profiles and their consequent effects on diagnosis.

Adolescent↗

PubMed2005

Anaerobic treatment of complex chemical wastewater in a sequencing batch biofilm reactor: process optimization and evaluation of factor interactions using the Taguchi dynamic DOE methodology.

The Taguchi robust experimental design (DOE) methodology has been applied on a dynamic anaerobic process treating complex wastewater by an anaerobic sequencing batch biofilm reactor (AnSBBR). For optimizing the process as well as to evaluate the influence of different factors on the process, the uncontrollable (noise) factors have been considered. The Taguchi methodology adopting dynamic approach is the first of its kind for studying anaerobic process evaluation and process optimization. The designed experimental methodology consisted of four phases--planning, conducting, analysis, and validation connected sequence-wise to achieve the overall optimization. In the experimental design, five controllable factors, i.e., organic loading rate (OLR), inlet pH, biodegradability (BOD/COD ratio), temperature, and sulfate concentration, along with the two uncontrollable (noise) factors, volatile fatty acids (VFA) and alkalinity at two levels were considered for optimization of the anae robic system. Thirty-two anaerobic experiments were conducted with a different combination of factors and the results obtained in terms of substrate degradation rates were processed in Qualitek-4 software to study the main effect of individual factors, interaction between the individual factors, and signal-to-noise (S/N) ratio analysis. Attempts were also made to achieve optimum conditions. Studies on the influence of individual factors on process performance revealed the intensive effect of OLR. In multiple factor interaction studies, biodegradability with other factors, such as temperature, pH, and sulfate have shown maximum influence over the process performance. The optimum conditions for the efficient performance of the anaerobic system in treating complex wastewater by considering dynamic (noise) factors obtained are higher organic loading rate of 3.5 Kg COD/m3 day, neutral pH with high biodegradability (BOD/COD ratio of 0.5), along with mesophilic temperature range (40 degrees C), and low sulfate concentration (700 mg/L). The optimization resulted in enhanced anaerobic performance (56.7%) from a substrate degradation rate (SDR) of 1.99 to 3.13 Kg COD/m3 day. Considering the obtained optimum factors, further validation experiments were carried out, which showed enhanced process performance (3.04 Kg COD/m3-day from 1.99 Kg COD/m3 day) accounting for 52.13% improvement with the optimized process conditions. The proposed method facilitated a systematic mathematical approach to understand the complex multi-species manifested anaerobic process treating complex chemical wastewater by considering the uncontrollable factors.

Algorithms↗

PubMed1995

Statistical methodology for estimating twin similarity with respect to a dichotomous trait.

Statistical methodology is presented for the estimation of twin similarity with respect to a dichotomous trait. The methodology focuses on the intraclass correlation as the parameter of interest and is analogous to methodology commonly applied to continuous outcome data. For inference problems involving a single sample, confidence interval construction and significance testing are discussed. For two sample problems, test procedures are provided that are an alternative to an approach recently presented by Ramakrishnan et al. [(1992) Genet Epidemiol 9:273-287 (1)]. Two examples based on published data sets are given to illustrate the proposed techniques.

Confidence Intervals↗

PubMedDate not supplied

Informal care and economic appraisal: a discussion of possible methodological approaches.

The role played by informal carers in the care of people with chronic disabilities is well known. Given its importance, it is essential to consider the evaluation methodology applied in economic appraisals of different care options. Few studies attempt any evaluation and those that do use varied, inconsistent and controversial methodologies. This paper aims to elicit the major issues and methodological problems related to economic appraisal of informal care. The main concern over the present methods utilized is the lack of explicit exploration of the benefits, as perceived by carers. Carers, through their decision to care it is argued, will consider both costs and benefits. Although concepts encompassed by benefits tend to be less tangible they may considerably outweigh any financial burdens. Various methods have been utilized in the past. Financial outlays are fairly straightforwardly costed, personal effort on the part of carers causes more problems. Methods applied include: the cost of substitute services; state benefits; and travel time values. The most useful is probably the latter, although it is not problem-free. Assessing benefits relating to concepts of direct and indirect utility and welfare is more complex and difficult to measure. Despite considerable literature on carers' attitudes, often these concepts are not applied (especially to residential care options) or if they are, negative aspects are emphasized (with domiciliary care). A useful application of economic appraisal would elicit optimal solutions to care dilemmas. Producing economic burden information about informal care may not be particularly constructive. Brief assessment of eight scenarios of care, considering cost differences for the public sector and the preferences of patient and carer gives insight to the problem. It emphasizes the complexity of the issue and the essential role likely to be placed on care managers in helping carers to maximize the net benefit of their efforts.

Caregivers↗

PubMed2004

Calculation of quality adjusted life years in the published literature: a review of methodology and transparency.

Economic evaluations alongside randomised controlled trials (RCTs) are increasingly being designed to prospectively collect patient-specific resource use and preference-based health status (utility) data. This paper examines the ways in which preference-based health status (utility) data are used to generate quality adjusted life years (QALYs). A literature review was carried out which identified 23 published cost utility analyses suitable for inclusion. The methodology employed to calculate QALYs was not always consistent, as well as being poorly reported. The use of different methodologies in the calculation of QALYs may influence the magnitude and direction of results of evaluations. Analysts need to be consistent and fully transparent in the methodology chosen to calculate QALYs.

Cost-Benefit Analysis↗

PubMed2006

Evaluation of bone healing enhancement by lyophilized bone grafts supplemented with platelet gel: a standardized methodology in patients with tibial osteotomy for genu varus.

Orthopedic practice may be adversely affected by an inadequate bone repair that might compromise the success of surgery. In recent years, new approaches have been sought to improve bone healing by accelerating the rate of new bone formation and the maturation of the matrix. There is currently great interest in procedures involving the use of platelet gel (PG) to improve tissue healing, with satisfactory results both in vitro and in maxillofacial surgery. Otherwise, to our knowledge, only a preliminary clinical study was undertaken in the orthopedic field [Kitoh et al., Bone 2004;35:892-898] and the efficacy of PG is still controversial. Our paper focuses on the effect on bone regeneration by adding PG to lyophilized bone chips used for orthopedic applications. The clinical model and the laboratory methodology were standardized. As a clinical model, we employed the first series of patients of a randomized case-control study undergoing high tibial osteotomy (HTO) for genu varus. Ten subjects were enrolled: in 5 patients lyophilized bone chips supplemented with PG were inserted during tibial osteotomy (group A); 5 patients were used as a control (group B) and lyophilized bone chips without gel were applied. Forty-five days after surgery, computed tomography scan guided biopsies of grafted areas were obtained and the bone maturation was evaluated by a standardized methodology: the osteogenic and angiogenic processes were semi-quantitatively characterized by using histomorphometry, and the mineral component of the lyophilized and host bone was analyzed by using X-ray diffraction technique with sample microfocusing and microradiography. Lyophilized bone with PG seems to accelerate the healing process, as shown by new vessel formation and deposition of newly formed bone, with no evidence of inflammatory cell infiltrate, when compared with lyophilized bone without gel. On the contrary, lyophilized bone undergo a resorption process, and a fibrous tissue often fills the spaces between chips. A histiocytic/giant-cell reaction is sometimes present. Otherwise, no differences have been found concerning microstructure. Our findings show the reliability of the methodology used to monitor early bone repair. The completion of the study and the evaluation of the ultimate clinical outcome are necessary in order to verify PG in vivo effects in orthopedic surgery.

Adult↗

PubMed2002

Methodology of predicting approximate shapes and size distribution of micelles: illustration for simple models.

We propose an efficient methodology for predicting approximate shapes and size distribution of micelles. The methodology is a judicious combination of a conventional thermodynamic approach, the reference interaction site model (RISM) theory, and the Monte Carlo (MC) simulated annealing technique. Solvent effects are fully incorporated using the RISM theory with our robust and very efficient algorithm for solving the RISM equations, and the MC technique is applied only to surfactant molecules. The methodology is potentially applicable to realistic models of surfactant and solvent molecules with all-atom potentials. As the first step, however, it is illustrated for simplified models having only essential characteristics of the amphiphiles. We estimate the critical micelle concentration, approximate shapes, and size distributions at some surfactant concentrations. Roles of the solvent and effects due to the type of the surfactant molecule are discussed in detail.

Journal Article↗

PubMed2004

Evaluation of in vivo bioequivalence methodology for topical clobetasol 17-propionate based on pharmacodynamic modeling using Chinese skin.

The United States Food and Drug Administration recommends pilot dose duration-response and pivotal bioequivalence studies to be conducted using reflectance colorimetry for assessment of the in vivo bioequivalence of topical dermatologic corticosteroids. The major objectives of the present studies were to examine the applicability of the standardized pharmacodynamic modeling-based methodology to super-potent clobetasol 17-propionate (CP) in the Chinese population and to evaluate the bioequivalence of two generic ointments and four generic creams containing 0.05% (w/w) CP with respect to Dermovate formulations using such methodology. In the pilot dose duration-response study, although the E(max) model (where E(max) is the maximum fitted value of AUEC, which is the area under the baseline-corrected, untreated control-site-corrected a* scale data from 0 to 24 h after drug removal) did not provide acceptable model fits, E(max) parameter estimates of -38.97 +/- 3.62 and -41.89 +/- 11.28 a*-scale. h, and ED(50) (dose duration required to achieve 50% of the fitted E(max) value) estimates of 0.40 +/- 0.37 and 0.42 +/- 0.16 h were obtained for Dermovate ointment and cream, respectively, by population analyses. The estimates for the two formulations were not statistically different, so in vivo bioequivalence studies were conducted at an ED(50)dose duration of approximately 0.5 h for both Dermovate formulations. The results demonstrated that one generic ointment was bioequivalent to Dermovate, whereas the other was not. None of the generic creams were shown to be bioequivalent to Dermovate cream. The in vivo bioequivalence data from the vasoconstriction assay were linearly correlated with stratum corneum uptake of the drug at the same dose duration until the maximal vasoconstriction response was achieved. The studies illustrated the applicability of the standardized pharmacodynamic modeling-based methodology in detecting the product differences between a variety of generic 0.05% CP formulations and reference Dermovate formulations in Chinese skin.

Administration, Topical↗