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PubMed1986

A methodology for assessing carcinogenic hazards of chemicals.

Assessment of carcinogenic hazards of substances involves evaluation and classification of qualitative and quantitative data, including the attendant uncertainty. Recently proposed EPA guidelines represent a significant step towards a uniform carcinogenic risk assessment procedure and its appropriate use. The Methodology for Assessing Carcinogenic Hazards of Chemicals proposed here shares common characteristics with the EPA guidelines but it also focuses on other aspects of carcinogen assessment, not addressed by the guidelines, such as: folding together quantitative and qualitative data into a combined hazard index; classification of limited, incomplete or flawed qualitative data; utilization of quantitative risk estimates based on weak qualitative evidence. The elements are used to assess carcinogenic hazards of chemicals, qualitative and quantitative. The qualitative assessment consists of stratification into one of five categories of weight-of-evidence, whereas quantitative assessment consists of stratification into one of four potency categories on the basis of carcinogenic unit risk estimate. Carcinogenic hazard index, codified in letters A to E, is derived from the quantitative and qualitative elements of assessment in a two-dimensional matrix. The matrix is designed so that weaker evidence for carcinogenicity requires a correspondingly higher unit risk value for a given score. Assessment of 100 chemicals using our methodology shows a good distribution of scores from A to E. Group B, which can be described as moderately hazardous, is most frequently represented. The methodology represents a mixture of two possible approaches to assessing hazards of carcinogens: one which gives the highest rank to those likely to produce the greatest risk, the other which ranks highest those most likely to produce cancer in humans. By using this combined approach, it is ensured that a chemical hazardous on either count is not missed. The methodology also makes maximum use of all available data without over-interpreting some highly uncertain procedures such as quantitative risk estimation or extrapolation of animal response to humans.

Animals↗

PubMed1999

Methodological triangulation in a study of social support for siblings of children with cancer.

Triangulation is an approach to research that is becoming increasingly popular among nurse researchers. Five types of triangulation are used in nursing research: data, methodological, theoretical, researcher, and analytical triangulation. Methodological triangulation is an attempt to improve validity by combining various techniques in one study. In this article, an example of quantitative and qualitative triangulation is discussed to illustrate the procedures used and the results achieved. The secondary data used as an example are from a previous study that was conducted by the researcher and investigated nursing interventions used by pediatric oncology nurses to provide social support to siblings of children with cancer. Results show that methodological triangulation was beneficial in this study for three reasons. First, the careful comparison of quantitative and qualitative data added support for the social support variables under investigation. Second, the comparison showed more in-depth dimensions about pediatric oncology nurses providing social support to siblings of children with cancer. Finally, the use of methodological triangulation provided insight into revisions for the quantitative instrument.

Child↗

PubMed2003

Do we need methodological theory to do qualitative research?

Positivism is frequently used to stand for the epistemological assumption that empirical science based on principles of verificationism, objectivity, and reproducibility is the foundation of all genuine knowledge. Qualitative researchers sometimes feel obliged to provide methodological alternatives to positivism that recognize their different ethical, ontological, and epistemological commitments and have provided three theories: phenomenology, grounded theory, and ethnography. The author argues that positivism was a doomed attempt to define empirical foundations for knowledge through a rigorous separation of theory and evidence; offers a pragmatic, coherent view of knowledge; and suggests that rigorous, rational empirical investigation does not need methodological theory. Therefore, qualitative methodological theory is unnecessary and counterproductive because it hinders critical reflection on the relation between methodological theory and empirical evidence.

Empirical Research↗

PubMedDate not supplied

The prevalence and incidence of pressure ulcers in the hospice setting: analysis of two methodologies.

Hospice patients may be at greater risk of pressure ulcer development than most patients. This descriptive study explored the prevalence and incidence of pressure ulcers in the hospice setting, utilizing both a prospective and retrospective methodological approach. Levine's theory of the four principles of conservation formed the theoretical basis for the study, and the Braden Scale for Predicting Pressure Ulcer Risk was used for data collection. Prevalence of pressure ulcers was noted to be 13 percent in the study. Incidence of pressure ulcers was found to be zero percent using prospective methodology and 13 percent using retrospective methodology. Five of eight ulcers (62 percent) occurred within two weeks of patient death. Factors related to pressure ulcer development are presented, as well as a discussion of using research methodologies in the hospice setting. The article suggests the need for preventive protocols for skin care for patients who are at risk for pressure ulcer development.

Female↗

PubMed1988

Postmarketing surveillance methodologies.

This article describes and discusses the strengths and limitations of the major pharmacoepidemologic methodologies employed in postmarketing drug surveillance and describes the current status of the U.S. surveillance system. The main methodologies employed in postmarketing drug surveillance include controlled clinical trials, observational epidemiologic studies (cohort, case-control, cross-sectional), demographic methods, drug utilization surveys, spontaneous reports, and automated databases linking medications and disease. Examples of pharmacoepidemiologic studies using each of these methodologies are presented. When a question arises about the efficacy and/or safety of a marketed drug, typically a mixture of these study methodologies is employed. The article concludes with a brief discussion of the role of the Food and Drug Administration, pharmaceutical manufactures, and academic institutions in initiating and conducting postmarketing drug studies.

Evaluation Studies as Topic↗

PubMedDate not supplied

Impact of risk adjusted clinical outcomes methodology--quality measures on hospital mortality data: a statistical and case study approach.

The effectiveness of risk adjustment in improving mortality as a performance measure for hospitals remains uncertain. New techniques of risk adjustment should be empirically tested, and health care professionals, using the data derived from such measures, should be queried before final acceptance of these technologies of measurement is warranted. The Risk Adjusted Clinical Outcomes Methodology-Quality Measures (RACOM-QM), a relatively new risk-adjustment methodology developed by the QuadraMed Corporation, was used by Maryland hospitals for risk adjustment for the first time in 1997. A research study was undertaken by the Maryland Hospital Association to determine the impact of RACOM-QM on mortality rates, its empirical validity, and its acceptance in the field. The relationship between RACOM-QM mean risk scores and mortality rates was examined using inpatient hospital mortality data for Maryland in 1996. Using these same data, the empirical relationship between risk-adjusted and unadjusted mortality by diagnosis-related group (DRG) was also investigated. Case studies were undertaken to glean information about the use and acceptability of this new methodology in 2 hospital settings in Maryland. There was a strong relationship between mean mortality risk scores and mortality rates. The analysis of the empirical relationship between risk-adjusted and unadjusted mortality by DRG yielded support for the impact of RACOM-QM in adjusting inpatient mortality rates. The case studies supported the utility of this method of risk adjustment in increasing the interpretation of mortality data and in helping to identify areas in which to investigate quality in more depth in 2 hospital settings. This study provides overall support for the usefulness of risk adjustment and, specifically, the RACOM-QM, in increasing the interpretation of inpatient mortality rates in Maryland's acute care hospitals. This study also suggests that use of the RACOM-QM improved comparative analysis of inpatient mortality rates among Maryland hospitals. Finally, the results of the case study analysis suggest that improved internal review of mortality rates and increased clinician acceptance of these rates as indicators of performance were enhanced by the use of a risk adjustment methodology.

Diagnosis-Related Groups↗

PubMed2003

Is hand splinting effective for adults following stroke? A systematic review and methodologic critique of published research.

BACKGROUND: Upper limb hemiplegia after stroke is common and disabling. Hand splints are widely used to prevent contracture and reduce spasticity. OBJECTIVE: To assess the effectiveness of hand splinting on the hemiplegic upper extremity following stroke. SEARCH STRATEGY: A search was conducted of the Cochrane Central Register of Controlled Trials; the electronic databases MEDLINE, EMBASE, CINAHL, PEDro, SCI, SSCI; websites of professional associations; reference lists in trial reports and other relevant articles. SELECTION CRITERIA: Studies of the effect of upper extremity splinting on motor control, functional abilities, contracture, spasticity, or pain in the hand or wrist. DATA COLLECTION AND ANALYSIS: Validity of studies was assessed systematically and a content analysis was conducted of the methodologies used. Methodological quality of randomized trials was rated by two independent assessors using the PEDro scale. RESULTS: Nineteen studies were appraised for content. Of these, most (63%) were reports of case series. Four studies (21%) were randomized controlled trials. Methodological scores of trials ranged from 2 to 8 (maximum possible score 10). One trial of nominally 'medium' quality reported that inflatable arm splinting makes no difference to hand function (mean difference on Fugl-Meyer Assessment -0.12, 95% confidence interval (CI) -9.8 to 9.6). The remaining trials investigated effects of thermoplastic splints; one trial of 'high quality' reported no difference in contracture formation in the wrist and finger flexor muscles after wearing a hand splint which positioned the wrist in the traditional functional position for 12 hours each night for four weeks (mean difference in range of movement after four weeks was 1 degree, 95% CI -3.7 degrees to 6.1 degrees; power >80%). All remaining trials were of poor methodological quality. Limited research and lack of a no-splint control group in all trials to date limit the usefulness of these results. REVIEWER'S CONCLUSION: There is insufficient evidence to either support or refute the effectiveness of hand splinting for adults following stroke.

Contracture↗

PubMed2004

A systematic review of the methodological quality and extent to which evaluation studies measure the usability of orthopaedic shoes.

OBJECTIVE: To determine the methodological quality of studies evaluating orthopaedic shoes and orthopaedic shoe provisions. To what extent do studies evaluating orthopaedic shoes prescribed for patients with degenerative disorders of the foot, rheumatoid arthritis, diabetes mellitus and neurological foot disorders, focus on the aspects of the International Organization for Standardization (ISO) definition of usability, i.e., effectiveness, efficiency, satisfaction, and context of use? DESIGN: Systematic review. METHODS: A systematic literature search was performed to identify randomized controlled trials (RCTs) concerning orthopaedic shoes and orthopaedic shoe inserts. The methodological quality of the studies was assessed independently by two raters, based on the 19 items of the 'Maastricht-Amsterdam criteria list'. The studies were assessed against the parameters of the ISO definition of usability. RESULTS: Eleven RCTs were included. The methodological scores ranged from 8 to 14 out of 19 possible points. Eleven studies focused on the effectiveness of the orthopaedic shoes and orthopaedic shoe inserts, two of which reported outcome measures and conclusions related to the efficiency of the studied orthopaedic shoes and orthopaedic shoe inserts. Four studies reported some form of patient satisfaction and only three studies paid attention to the context of use. CONCLUSIONS: The methodological quality of the RCTs as assessed according to the 19 different criteria varied considerably. The present review shows that current scientific literature concerning the usability of orthopaedic shoes focuses mainly on effectiveness at the expense of the other domains of usability, i.e., efficiency, satisfaction and context of use.

Evaluation Studies as Topic↗

PubMed2003

Bereavement research: methodological issues and ethical concerns.

Principles of conducting research in the field of bereavement are introduced. The review focuses on issues of design and methodology, and considers ethical concerns, particularly in view of the fact that bereaved people are frequently in acute grief when scientific study is conducted. Accurate assessment is fundamental, and requires methodologically stringent procedures. The merits and disadvantages of different types of investigation are considered, the often-neglected need for control groups is described, and quantitative versus qualitative methodological approaches are reviewed. Also considered are biases due to selection and limits on generalizability. Understanding of ethical matters arising in this field of research is essential for the conduct of worthwhile research, and involves methodological sophistication.

Adaptation, Psychological↗

PubMed2005

Methodological issues in clinical trials of opioids for chronic pain.

Clinical trials of opioid analgesics for chronic pain are recognized to frequently fail to distinguish the analgesic effect from placebo, despite known efficacy of the drug. This paper reviews the methodologic features of such trials that may be associated with risk of failure. A literature search yielded 23 randomized placebo-controlled studies of opioids with at least one week of continuous treatment; contacting pharmaceutical companies yielded six additional studies. A classification system and standard terminology were developed for describing the methodologic features of these trials. The methodologic features that appeared to augur well for success of the trials were slow titration of medications, flexible dosing, minimizing concomitant and rescue analgesics, homogeneous samples, particularly in terms of opioid use upon entry, fewer study sites (for the same sample size), and including as much data as possible in statistical analyses. Study designs that lead to high dropout rates lack internal validity, unless dropout is the intended endpoint of the trial. Opioid analgesics should be studied in a manner that is clinically relevant, and that supports internal validity. More systematic attention is needed to clinical research methodology.

Analgesics, Opioid↗

PubMed2006

New methodology to obtain a calibration model for noninvasive near-infrared blood glucose monitoring.

This paper reports new methodology to obtain a calibration model for noninvasive blood glucose monitoring using diffuse reflectance near-infrared (NIR) spectroscopy. Conventional studies of noninvasive blood glucose monitoring with NIR spectroscopy use a calibration model developed by in vivo experimental data sets. In order to create a calibration model, we have used a numerical simulation of light propagation in skin tissue to obtain simulated NIR diffuse reflectance spectra. The numerical simulation method enables us to design parameters affecting the prediction of blood glucose levels and their variation ranges for a data set to create a calibration model using multivariate analysis without any in vivo experiments in advance. By designing the parameters and their variation ranges appropriately, we can prevent a calibration model from chance temporal correlations that are often observed in conventional studies using NIR spectroscopy. The calibration model (regression coefficient vector) obtained by the numerical simulation has a characteristic positive peak at the wavelength around 1600 nm. This characteristic feature of the regression coefficient vector is very similar to those obtained by our previous in vitro and in vivo experimental studies. This positive peak at around 1600 nm also corresponds to the characteristic absorption band of glucose. The present study has reinforced that the characteristic absorbance of glucose at around 1600 nm is useful to predict the blood glucose level by diffuse reflectance NIR spectroscopy. We have validated this new calibration methodology using in vivo experiments. As a result, we obtained a coefficient of determination, r2, of 0.87 and a standard error of prediction (SEP) of 12.3 mg/dL between the predicted blood glucose levels and the reference blood glucose levels for all the experiments we have conducted. These results of in vivo experiments indicate that if the parameters and their vibration ranges are appropriately taken into account in a numerical simulation, the new calibration methodology provides us with a very good calibration model that can predict blood glucose levels with small errors without conducting any experiments in advance to create a calibration model for each individual patient. This new calibration methodology using numerical simulation has promising potential for NIR spectroscopy, especially for noninvasive blood glucose monitoring.

Algorithms↗

PubMed2006

Comparison of processing and sectioning methodologies for arteries containing metallic stents.

The histological study of arteries with implanted metallic scaffolding devices, known as stents, remains a technical challenge. Given that the arterial response to stent implantation can sometimes lead to adverse outcomes, including the re-accumulation of tissue mass within the stent (or in-stent restenosis), overcoming these technical challenges is a priority for the advancement of research and development in this important clinical field. Essentially, the task is to section the stent-tissue interface with the least amount of disruption of tissue and cellular morphology. Although many methacrylate resin methodologies are successfully applied toward the study of endovascular stents by a variety of research laboratories, the exact formulations, as well as subsequent processing and sectioning methodology, remain largely coveted. In this paper, we describe in detail a methyl methacrylate resin-embedding methodology that can successfully be applied to tungsten carbide blade, as well as saw and grinding sectioning methods and transmission electron microscopy. In addition, we present a comparison of the two sectioning methodologies in terms of their effectiveness with regard to morphological, histochemical, and immunohistochemical analyses. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials.

Acrylic Resins↗

PubMed2006

Methodologic European external quality assurance for DNA sequencing: the EQUALseq program.

BACKGROUND: DNA sequencing is a key technique in molecular diagnostics, but to date no comprehensive methodologic external quality assessment (EQA) programs have been instituted. Between 2003 and 2005, the European Union funded, as specific support actions, the EQUAL initiative to develop methodologic EQA schemes for genotyping (EQUALqual), quantitative PCR (EQUALquant), and sequencing (EQUALseq). Here we report on the results of the EQUALseq program. METHODS: The participating laboratories received a 4-sample set comprising 2 DNA plasmids, a PCR product, and a finished sequencing reaction to be analyzed. Data and information from detailed questionnaires were uploaded online and evaluated by use of a scoring system for technical skills and proficiency of data interpretation. RESULTS: Sixty laboratories from 21 European countries registered, and 43 participants (72%) returned data and samples. Capillary electrophoresis was the predominant platform (n = 39; 91%). The median contiguous correct sequence stretch was 527 nucleotides with considerable variation in quality of both primary data and data evaluation. The association between laboratory performance and the number of sequencing assays/year was statistically significant (P <0.05). Interestingly, more than 30% of participants neither added comments to their data nor made efforts to identify the gene sequences or mutational positions. CONCLUSIONS: Considerable variations exist even in a highly standardized methodology such as DNA sequencing. Methodologic EQAs are appropriate tools to uncover strengths and weaknesses in both technique and proficiency, and our results emphasize the need for mandatory EQAs. The results of EQUALseq should help improve the overall quality of molecular genetics findings obtained by DNA sequencing.

European Union↗

PubMed2000

An empirical comparison of alternative methodologies for the evaluation of configural displays.

Two different methodologies (visual, memory) were used to evaluate alternative versions of the same configural display. One version (composite display) had several graphical design techniques applied, whereas the other version (baseline display) did not. Two types of information probes (high-level property, low-level data) were administered. When the displays were visible during completion of the probes (visual methodology), the display manipulation had the largest impact on performance (composite display associated with better performance); when the displays were not visible (memory methodology) the probe manipulation had the largest impact on performance (high-level probes associated with better performance). These results are interpreted in light of the mutually interacting constraints introduced by factors in display design, task requirements, and the participants' cognitive and perceptual capabilities/limitations. Implications for both the design and the evaluation of displays and interfaces in general are discussed. Actual or potential applications of this research include design techniques for improving the quality of graphic displays and methodological insights for interpreting previous research and guiding future experimentation.

Analysis of Variance↗

PubMed1997

A methodology for optimally designing console panels for use by a single operator.

A seven-step methodology is presented to determine a dimensionally correct optimal layout of a console panel for a single operator. This methodology integrates the steps in the layout design process and uses a mathematical optimization model from facility design to obtain the optimal panel layout. A major difference in this methodology from previous work is that the mathematical optimization model incorporates factors that are only partially included in previous mathematical models. In addition, it includes the areas of the panel components as a new factor. This methodology is illustrated by the design of a nuclear power plant console panel.

Anthropometry↗

PubMed2005

Cost methodology of COMBINE.

OBJECTIVE: This article describes the methodology used in estimating the mean cost per patient of the interventions delivered in COMBINE, a randomized controlled trial (RCT) comparing pharmacotherapies and behavioral interventions for outpatient treatment of alcohol dependence. METHOD: Our methodology identifies a broad list of nonresearch activities necessary to implement the COMBINE interventions in standard clinical practice. For each activity, we include the time costs of clinical assessments and interventions by staff, the cost of space, laboratory charges and the cost of medical supplies. We also estimate the patients' time used for each of these activities. RESULTS: We present the estimated cost per activity for 15 intake assessments plus the Medical Management (MM) and Combined Behavioral Intervention (CBI) sessions for 9 of the 11 COMBINE sites. Labor costs represent the bulk of the total cost for all activities. The Form 90 AIR/ED is the most expensive intake activity both in terms of labor and space costs. The CBI session is more expensive than the MM session. CONCLUSIONS: Our methodology estimates the cost to treatment providers and to patients of implementing the COMBINE intervention in standard practice. Compared with previous methods, the prospective design of our methodology allows for higher quality data, and the detailed activity costing helps identify key cost drivers. Future analyses will present actual COMBINE intervention cost estimates based on trial data. Although this cost study is specific to the COMBINE interventions, the concepts, instruments and methods used here can be applied to any RCT.

Alcoholism↗

PubMedDate not supplied

[Capture-recapture methodology: an option for surveillance of non-communicable diseases in the elderly].

Capture-recapture methodology is used in Ecology to estimate the total size of wild animal populations. This method can be used in Epidemiology to estimate the incidence and prevalence of communicable and non-communicable diseases in a relatively inexpensive and quick way. Surveillance systems based on the use of this methodology are a potential alternative for monitoring non-communicable diseases in Brazil. This paper presents a brief review of fundamental capture-recapture methodology and its applications to Epidemiology. We also present a theoretical model for implementation of a diabetes mellitus surveillance system in the elderly using publicly available morbidity and mortality data sources and the capture-recapture methodology.

Aged↗

PubMed2004

[Quality of life and health: conceptual and methodological issues].

The quality of life (QL) concept has led to extensive scientific research and has been increasingly used by health care professionals treating a wide range of diseases. This paper addresses the historical use of the concept and specific issues linked to conceptual and methodological aspects of the QL construct within the health care context. Reviewing the literature, two aspects stand out: subjectivity and multidimensionality. In the methodological field, the construction and/or adaptation of QL measurement instruments appear as a significant trend. Theoretical and methodological efforts have helped clarify and improve the concept's adequacy. The QL construct is definitely interdisciplinary, encompassing contributions by different areas of knowledge and research, thereby improving its conceptual and methodological potential as a research instrument. Therefore, use of the concept can actually help improve both the quality and the integrated, multidimensional nature of health care from a perspective that views the latter as a basic citizen's right.

Health Status↗