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PubMed2004

Methodology for guideline development for the Seventh American College of Chest Physicians Conference on Antithrombotic and Thrombolytic Therapy: the Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy.

This article describes the methodology for the Seventh American College of Chest Physicians (ACCP) Conference on Antithrombotic and Thrombolytic Therapy: Evidence-Based Guidelines. Guideline authors began by specifying the population, the intervention and alternative, and the outcomes for each clinical question, and defined the criteria for eligible articles, including methodological criteria, for each recommendation. Librarians, in collaboration with guideline authors and methodologists, conducted systematic searches for evidence. Guideline authors systematically evaluated the evidence, considered the full range of benefits, risks, inconvenience, and costs associated with alternative management strategies, considered patients' underlying values and preferences, and made recommendations accordingly. To increase the likelihood that the recommendations adequately represent patient values and preferences, the development process included a review of recommendations by research methodologists, practicing generalists, and specialists. Chapters are organized so that evidence is clearly linked to the relevant recommendations, and that recommendations particularly sensitive to underlying values and preferences are explicitly identified. Authors paid careful attention to the strength of the underlying evidence and to the balance between risks and benefits, which are both reflected in the grades of recommendations. Thus, improvements to the process of making recommendations for the ACCP guidelines include the explicit definition of questions, transparent eligibility criteria for including studies, and the specification of values and preferences underlying recommendations where they are particularly relevant. In combination with our previous practice of grading recommendations according to their strength, and the methodological quality of the supporting studies, these innovations establish our guidelines as, by and large, evidence based.

Bias↗

PubMed2001

Psychosocial and pharmacological treatment of patients following deliberate self-harm: the methodological issues involved in evaluating effectiveness.

Development of effective treatments for patients following deliberate self-harm (self-poisoning or self-injury) is a very important element in suicide prevention. The randomized controlled trial (RCT) is the mainstay of evaluation of treatments. In a systematic review of the literature, the effectiveness of treatments based on RCTs was examined and the quality of the RCTs was assessed. Twenty trials were identified, and where possible, these were grouped on the basis of similarities among the types of treatment. In this paper, we examine the methodological aspects of the trials and consider what may be learned that will assist in the design of future studies in this field. The methodological quality of the trials was reasonable, but most trials included too few participants to detect clinically important differences in rates of repeated self-harm. In planning future trials, the following major issues should be addressed: investigators should perform power calculations to determine the number of subjects necessary to detect clinically important effects, provide information on method of randomization and interventions, use standard measures of outcome, and focus on homogeneous subgroups of patients. Improving the methodology of future studies in this field will be essential if sound evidence is to be obtained which can inform effective service provision for deliberate self-harm patients.

Humans↗

PubMed1986

Matching patients with treatments: conceptual and methodological issues.

The current enthusiasm for matching patients with optimal treatments rests on limited conceptual analyses. In addition, much of the existing research on patient-treatment matching has been based on methodological assumptions that are not commensurate with the complexity of the matching problem. Six key conceptual and methodological issues that underlie attempts to match patients with optimal forms of treatment and to conduct research on patient-treatment matching are outlined. The conceptual issues are: selecting effective matching variables, specifying the end result that matching is to enhance and determining the stage(s) in the treatment process at which matching decisions are to be made. The three methodological issues deal with the type of patient-treatment match or interaction effect and include: nonlinear interaction effects, higher-order interaction effects and multilevel interaction effects. Examples clarifying these issues are drawn from the literature on treating alcohol-dependent persons, but the issues are discussed at a broad level that permits generalization to treatment for many disorders. Implications for research on and the practice of "prescriptive treatment" are considered.

Alcohol Drinking↗

PubMed2006

Body composition during GH replacement in adults - methodological variations with respect to gender.

OBJECTIVE: Men with growth hormone deficiency (GHD) may be more sensitive to GH treatment than women in terms of changes in body composition. We have studied whether age, body-mass index (BMI) and the different types of methodology used to assess body composition may explain these differences. DESIGN: Forty-four men and forty-four women with GHD, closely matched for age and BMI, were studied before and after 6 months of GH replacement. The dose of GH was individually adjusted. Body composition was assessed by measurements of potassium-40, total body nitrogen (TBN), tritiated water dilution, dual-energy X-ray absorptiometry (DXA) and bioelectrical impedance analysis (BIA). Four- and five-compartment models for body composition were also calculated. RESULTS: The total daily dose of GH was similar in men and women at 6 months. Serum insulin-like growth factor-I (IGF-I) was higher in men than women at baseline and after 6 months of treatment (P = 0.01, paired t-test). The increment was, however, similar. In women, GH treatment reduced body weight and increased TBN. In both men and women, total body water and body cell mass increased, while total body fat (BF) mass decreased. At baseline, mean total BF varied considerably depending on the methodology used, with the highest value obtained from DXA. The changes in BF were, however, less dependent on the methodology, but DXA and BIA demonstrated the largest inconsistency between men and women. CONCLUSIONS: These results suggest that gender differences in body composition in response to GH treatment are small, if adjustments are made for baseline factors such as age, BMI and dose of GH. Different methods of body composition measurements produce different results, but changes in response to GH administration are less inconsistent.

Absorptiometry, Photon↗

PubMed1995

Methodology and characterization of an in vitro perfusion model for the mouse ovary.

Perfusion of intact ovaries in vitro has proved to be a suitable model for the study of ovarian events, such as ovulation and corpus luteum function, with advantages over cell culture systems of preserved three-dimensional structure with intact intercellular communication. This methodology has been described for several larger experimental animals. Development of genetically manipulated mouse strains and the larger availability of recombinant proteins and monoclonal antibodies in this species prompted the development of a mouse ovary perfusion system. In the present study, we describe the methodology for perfusion of mouse ovaries in vitro and characterize the model with respect to steroidogenesis, ovulatory efficiency and morphology. Swiss mice (30-45 g) were synchronized with a single injection of a GnRH agonist and laparotomy was performed on the morning of pro-oestrus. The right ovary and its vasculature, after cannulation on the arterial side, were surgically isolated and transferred to a recirculating perfusion system, and were perfused for 20 h. The ultrastructure of the ovaries after 20 h of perfusion was examined by transmission electron microscopy, which showed well-preserved cellular organelles and nuclei and distinct tight junctions between endothelial cells. Unstimulated ovaries did not ovulate and secreted small quantities of progesterone. After addition of hCG (50 iu) or ovine LH (0.1 microgram ml-1), ovulations were observed in all perfused ovaries (2.6 +/- 0.5 and 2.0 +/- 0.3 ovulations per treated ovary, respectively). There was a distinct rise in progesterone output after hormone addition. When a phosphodiesterase inhibitor, isobutylmethylxanthine (0.2 mumol l-1), was added in combination with LH, the ovulation rate (7.4 +/- 1.2) was similar to that in vivo and progesterone secretion was further increased compared with other treatments. Since the mouse has become a very important experimental animal in medical research and we have the ability to genetically manipulate this species, this methodology for perfusing mouse ovaries in vitro may be a useful tool in future studies of ovarian physiology.

1-Methyl-3-isobutylxanthine↗

PubMedDate not supplied

[Teaching nursing care methodology in Paraná].

This inquiry has been carried out among professors in the Nursing program from Institutions of Higher Education in the State of Paraná. It aimed at investigating the teaching process of Health Care Assistance Methodology for Nursing, by promoting and opening possibilities for interchange among these professors by means of a Forum. Data were collected through a semistructured questionnaire sent by regular mail, fax, and email. The sample consists of 17 instruments answered by professors representing 8 educational institutions. These data have shown how relevant the teaching of Health Care Assistance Methodology for Nursing is, but its concept still poses disagreements. It points out the theoretical reference the professors carry, the pedagogical methodologies they use, and the articulation between theory and practice.

Brazil↗

PubMed2005

Alternative methodology for flexural strength testing in natural teeth.

The use of natural teeth for performing in vivo , in situ and/or in vitro studies has been widely observed in the dental field. The mechanical behavior of teeth subjected to masticatory efforts is commonly used as a variable of response. In conditions of malocclusion, the most relevant component accounting for the integrity of the dental structure is non-axial (flexural). This force, while acting on a tooth in function in the oral cavity, generates a similar situation as that of a beam in balance supporting a load concentrated on its free extremity. Based on this configuration, a methodology has been developed to investigate the behavior of teeth subjected to this kind of efforts, taking into consideration specific aspects of the tested teeth, such as the transversal section area and the moment of inertia. For determination of the transversal section area an image analysis program was used. For assessment of the other variables, a C++ language program was implemented utilizing the Borland Compiler C++ Builder, version 1.0, for Windows (Borland International, USA). The applicability of the developed methodology is illustrated in this article using bovine teeth. Our findings indicate that more accurate data can be obtained with the application of this methodology and that it is suitable for studies testing the flexural strength of extracted teeth, as a variable of response.

Animals↗

PubMedDate not supplied

[Methodological education and care strategies in basic health care].

This paper discusses methodological and care strategies or tools used in basic health care practice. It is based on the dialogue established between what we think and what we carry out at the Life Quality Promotion Outpatient Centers (APQVs). These centers are located at two basic health care centers in Porto Alegre/RS, Brazil. Its users are mostly adult and elderly patients with long-term illnesses. The proposal of this discussion arose from a research project financed by the Brazilian Council for Scientific and Technological Development--CNPq, and integrates a thematic network called Education and Care Methodologies to Promote Life Quality. Starting from this empirical and conceptual base, methodological tools were built to develop nursing consulting services in outpatient health care to individuals and groups. This article aims to present relational and operational concepts used in care at these services.

Brazil↗

PubMed2003

Research methodologies to assess teaching in psychiatric residency: a literature review.

OBJECTIVES: Research methodologies in psychiatry have followed both the changes in mental health care and the need of updating programs of medical residency. To identify empirical articles in the indexed literature from 1997 to 2002, with the aim of analyzing and discussing methodological aspects of research dealing with the description and assessment of residency programs in psychiatry. METHOD: The bibliographic survey was performed using MedLine, PsycLit, Web of Science, and Lilacs. Twenty-one articles were identified. RESULTS: Nineteen studies were characterized as exploratory-descriptive and two as experimental. Data collection used questionnaires in 12 of them, and combined techniques in the other seven and the two experimental studies had data collected by tests applied before and after the teaching intervention. Most of the subjects were residents and program directors. Fifteen studies used statistical analysis. CONCLUSIONS: All the articles outlined the problems based on literature reviews. Most of the studies made use of standard techniques of social research and only two used experimental procedures. Only three studies employed external measures in order to establish correlations with the collected data. Procedures to validate and assess the reliability of the instrument by means of pilot-studies were absent in 11 studies, what may indicate methodological biases.

Internship and Residency↗

PubMed1998

Association between the angiotensin-converting enzyme-insertion/deletion polymorphism and diabetic nephropathy: a methodologic appraisal and systematic review.

Recent studies have implicated a variant of the angiotensin-converting enzyme gene (ACE), associated with increased activity of this enzyme, in the development and progression of diabetic nephropathy. This study provides a systematic review of all cross-sectional, case-control, and cohort studies in patients with insulin-dependent (IDDM) or non-insulin-dependent (NIDDM) diabetes mellitus of any race, examining the relationship between the ACE-insertion/deletion polymorphism and nephropathy. Nineteen studies in 21 populations published between 1994 and 1997 presenting data on 5336 patients were reviewed. Two investigators independently assessed the studies on methodologic quality, performance of study, and association between the ACE-insertion/deletion polymorphism and nephropathy. Separate analyses of the relationship between genotype and allele frequencies were performed for patients with IDDM and NIDDM by race, using Peto's odds ratio. In Caucasians with IDDM, pooling was not performed due to heterogeneity of the studies, but among the homogeneous studies, no association was detected. Likewise, no association was observed in Caucasian patients with NIDDM (odds ratio [OR], 1.10; 95% confidence interval [95% CI], 0.83 to 1.45). In Asian patients with NIDDM, the risk of nephropathy was increased in the presence of the DD or ID genotype (OR, 1.88; 95% CI, 1.42 to 2.85). Although this analysis fails to confirm an association between the ACE-insertion/deletion genotype and nephropathy in Caucasians with NIDDM or IDDM, a role for this genetic marker in Asian patients cannot be ruled out. However, due to methodologic limitations of individual studies, no definite conclusions can be drawn from this analysis. Clearly, more rigorous methodology needs to be applied in future studies.

Adult↗

PubMed1994

Functional analysis methodology: Some closing comments.

Functional analysis methodologies have emerged as powerful tools in research on the assessment and treatment of severe behavior disorders. Although the defining feature of these approaches is the systematic identification of environmental determinants of behavior, research methodology has varied widely with respect to the arrangements used to demonstrate experimental control as well as the types of variables subject to analysis. This commentary summarizes methodological and conceptual issues that have been raised in current research and offers some suggestions for their resolution.

Journal Article↗

PubMed2000

PCR-based methodology for the determination of the photoprotection afforded by sunscreen application.

We have applied a PCR-based methodology to study the DNA damage induced by UV-A, UV-B and sunlight itself. Our results, employing a cell-free system, indicate that UV-B (310 nm) is approximately 30-fold more potent at inhibiting DNA synthesis than UV-A (365 nm). We were also able to show that 20 min of sunlight exposure on a summer day induced DNA damage capable of inhibiting DNA synthesis. Hence, this methodology has a sensitivity suitable to detect biologically relevant doses of UV light. In addition, we propose that this technique may be suitable to assess the relative photoprotection of commercially available sunscreens. We present here preliminary data on the photoprotection afforded by the topical application of sunscreen. This photoprotection was measured by a reduction in the subsequent UV-B- and UV-A-induced DNA damage when sunscreen was applied. Our results demonstrate that the particular sunscreen tested was effective against both UV-B and UV-A. However, the estimated photoprotective factor of the sunscreen (against both UV-A and UV-B) was approximately tenfold less than the stated Sun Protection Factor (SPF) of 25. This methodology may also be useful in identifying new photoprotective agents by assessing their relative value as UV-B and UV-A absorbing agents.

Animals↗

PubMed1997

Differences in the methodology and data of economic evaluations of a health programme. The case of hepatitis B vaccination programmes in Spain.

Economic evaluations of hepatitis B vaccination programmes in Spain or particular regions of Spain were identified and analysed, and their methodologies and data were compared. The results revealed important differences in methodology and the way in which different parameters, such as duration of immunity, costs and sources of cost data, were defined and measured. Some of these variations could be justified by the need to adapt studies to specific contexts, while others appeared arbitrary. Although it is understandable that there should be a substantial amount of heterogeneity between studies, greater efforts need to be made to reduce unnecessary variations in the way in which different parameters are measured. Increasing standardisation in methodology, which nevertheless takes into account inevitable variations due to changing circumstances and perspectives, will help to make economic evaluation a more attractive proposition for decision makers.

Delivery of Health Care↗

PubMed1998

Methodological quality of economic modelling studies. A case study with hepatitis B vaccines.

The notable increase in the quantity of economic evaluations in the last 2 decades has not been matched by good methodological standards. This problem is particularly evident in the field of economic evaluations of hepatitis B vaccines. The results of 2 systematic reviews conducted by us in 1993 and 1996 showed three problem areas. A sizeable minority of study reports failed to provide a clear study aim, showing a basic ignorance of the first rule of conducting scientific research. The basic epidemiological assumptions upon which the economic models were based showed variability which persisted even after stratification, raising the question of the accuracy of the epidemiological knowledge base of hepatitis B infection and its progression. Lastly, many of the studies showed weaknesses in basic methods of conducting and reporting economic evaluations. Examination of these problem areas led us to conclude that no conclusions about the efficiency of hepatitis B vaccines could be drawn from the available evidence. Addressing the problem of poor methodological standards concerns the whole research community. However, as a proportion of economic evaluations are published, one obvious means of exerting pressure to increase and maintain methodological standards is the editorial and peer review process. Editors of specialist and general medical journals should agree on and enforce common explicit guidelines for study conduct and reporting, following the example of the British Medical Journal.

Hepatitis B↗

PubMed2004

Longitudinal versus cross-sectional methodology for estimating the economic burden of breast cancer: a pilot study.

BACKGROUND: Projecting future breast cancer treatment expenditure is critical for budgeting purposes, medical decision making and the allocation of resources in order to maximise the overall impact on health-related outcomes of care. Currently, both longitudinal and cross-sectional methodologies are used to project the economic burden of cancer. This pilot study examined the differences in estimates that were obtained using these two methods, focusing on Maryland, US Medicaid reimbursement data for chemotherapy and prescription drugs for the years 1999-2000. METHODS: Two different methodologies for projecting life cycles of cancer expenditure were considered. The first examined expenditure according to chronological time (calendar quarter) for all cancer patients in the database in a given quarter. The second examined only the most recent quarter and constructed a hypothetical expenditure life cycle by taking into consideration the number of quarters since the respective patient had her first claim. RESULTS: We found different average expenditures using the same data and over the same time period. The longitudinal measurement had less extreme peaks and troughs, and yielded average expenditure in the final period that was 60% higher than that produced using the cross-sectional analysis; however, the longitudinal analysis had intermediate periods with significantly lower estimated expenditure than the cross-sectional data. CONCLUSIONS: These disparate results signify that each of the methods has merit. The longitudinal method tracks changes over time while the cross-sectional approach reflects more recent data, e.g. current practice patterns. Thus, this study reiterates the importance of considering the methodology when projecting future cancer expenditure.

Antineoplastic Agents↗

PubMed2001

Progress in methodologies for evaluating bioequivalence of topical formulations.

Assessment of bioequivalence of topical dermatological formulations is a challenge. Currently, comparative clinical studies are used to establish bioequivalence for most formulations (except corticosteroids). This article reviews different in vivo methodologies for determining bioequivalence, and the progress made in this area. Dermatopharmacokinetics is the term used to describe the pharmacokinetics of topically applied drugs in the stratum corneum. A tape stripping procedure used in dermatopharmacokinetic methodology measures the drug concentration in stratum corneum at the site of application. Various studies have shown dermatopharmacokinetics to be a reliable and reproducible method for determining bioequivalence, and have indicated that it is applicable for all topical dermatological drug products. However, confidence in this methodology needs to be established, particularly regarding its relevance to clinical drug efficacy.

Administration, Topical↗

PubMed2005

Methodological challenges posed by economic evaluations of early childhood intervention programmes.

Early childhood intervention programmes have emerged in recent years with the aim of fostering the cognitive and social-emotional functioning and physical health of preschool children and enhancing their emerging competencies. This article presents a structured critical appraisal of economic evaluations of early childhood intervention programmes. It highlights a range of methodological issues in the field. These include: the fidelity of the evaluation process; the selection of the appropriate comparison group given the complexity of care routinely provided; the appropriate perspective and coverage of the study; methodological concerns relating to cost and benefit measurement and valuation; analytical requirements relating to the form of sensitivity analysis and the decision rules adopted by decision makers; and the interpretation of the results in the light of contextual factors. It is concluded that more transparent methodological guidance is required for analysts conducting economic evaluations of early childhood intervention programmes in particular and of public health interventions in general. Greater multidisciplinary collaboration between social scientists should also enhance the development of ground-breaking methods in this field.

Child↗

PubMed2006

Meta-analysis of diagnostic and screening test accuracy evaluations: methodologic primer.

OBJECTIVE: Interest in evidence-based diagnosis is growing rapidly as diagnostic and screening techniques proliferate. In this article we provide an overview of systematic reviews of diagnostic performance and discuss in detail statistical methods for the most common variant of the problem: meta-analysis of studies in which a pair of estimates of sensitivity and specificity is reported. The need to account for possible variations in threshold for test positivity across studies led to the formulation of the Summary ROC (SROC) curve method. We discuss graphical and model-based ways to estimate, summarize, and compare SROC curves, and we present an example from a meta-analysis of data on techniques for staging cervical cancer. We also present a brief survey of the methodologic literature for addressing heterogeneity, correlated data, multiple thresholds per study, and systematic reviews of ROC studies. We conclude with a discussion of the significant methodologic challenges that continue to face investigators in this area of diagnostic medicine research. CONCLUSION: Systematic reviews of diagnostic performance are a rigorous approach to examining and synthesizing evidence in the evaluation of diagnostic and screening tests. The information from such reviews is needed by clinicians, health policy makers, researchers in diagnostic medicine, developers of diagnostic techniques, and the general public. However, despite progress in study quality and reporting and in methodologic development, major challenges confront investigators undertaking these reviews.

Diagnostic Techniques and Procedures↗