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Results for “methodological review”

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At least 127 records · Page 7Linked to original sources

PubMed1998

Cancer risk assessment of extremely low frequency electric and magnetic fields: a critical review of methodology.

This review provides a discussion of cancer risk assessment methodology pertinent to developing a strategy for extremely low frequency electric and magnetic fields (EMF). Approaches taken for chemical agents or ionizing radiation in six key topic areas are briefly reviewed, and then those areas are examined from the perspective of EMF, identifying issues to be addressed in developing a risk assessment strategy. The following recommendations are offered: 1) risk assessment should be viewed as an iterative process that informs an overall judgment as to health risk and consists of a complex of related activities incorporating both positive and negative data, tumor and nontumor end points, and human and nonhuman sources of information; 2) a hazard identification resulting in a conclusion of weak or null effects, such as may be associated with EMF, will need to assign significant weight to animal cancer bioassays conducted under defined exposure conditions as well as to human epidemiologic studies; 3) a default factor to account for possible age differences in sensitivity to carcinogenesis should be included in an EMF risk assessment; 4) lack of evidence of dose response and the apparent lack of DNA reactivity of EMF suggest that a safety (or uncertainty) factor or margin of exposure type of risk characterization may be most appropriate; and 5) an EMF risk assessment should permit at least tentative conclusions to be reached as to the limits of carcinogenic risk from exposure to EMF, and should also define an efficient research agenda aimed at clarifying uncertainties appropriate to a more complete assessment.

Animals↗

PubMed2006

A review of methodological quality of systematic reviews on multiple pregnancies.

We set out to determine the quality of existing systematic reviews on multiple pregnancies. We conducted an electronic search in MEDLINE (1951 - 2005), EMBASE (1974 - 2005) and the Cochrane Database for Systematic reviews (2005:2) and a hand-search of reference lists without any language restrictions to identify relevant reviews. Two reviewers independently selected review articles in which a publicly available database was searched for studies concerning multiple pregnancies, and assessed them for quality of methods of review. Information was extracted on framing of question, literature search and data synthesis. Of 342 citations 14 (4%) eligible reviews were identified. Only 8/14 reviews specified the review question. Adequate literature search without language restriction and the use of a reference list was found in 7/14 reviews, but the risk of missing studies was assessed in only 1/14 reviews. Quality assessment of included studies was reported in 7/14 and tabulation of their findings was reported in 8/14 reviews, but heterogeneity of results was evaluated in only 4/14 reviews. Meta-analysis was employed in 3/14 reviews. Systematic reviews of existing studies on multiple pregnancies are infrequent and it is difficult to generate robust inferences from them as they lack good methodology.

Bibliometrics↗

PubMed2006

A systematic review finds that methodological quality is better than its reputation but can be improved in physiotherapy trials in childhood cerebral palsy.

OBJECTIVES: To identify critical issues in performing randomized controlled trials (RCTs) on complex interventions such as physiotherapy in multifaceted disabilities like cerebral palsy (CP); to systematically assess how well trials handled patient characteristics, key components of complex interventions, and outcome assessments; to make suggestions for improving the effectiveness of physiotherapy research. DESIGN AND METHODS: A methodological review. An ongoing metareview served as sampling frame. RCTs on physiotherapy in children with CP published after 1990 were eligible. The main outcome measures were sampling, recruitment, and comparability of groups; defined components of a complex intervention; outcome measures according to the World Health Organization International Classification of Functioning and clinical interpretation of score change. RESULTS: Fifty-seven clinical trials were identified, of which 14 RCTs were included. Most studies used simple randomization, complemented by balancing techniques such as matching or stratification. Only three of 14 studies specified concealed allocation. Numerous studies provided sufficient details on components of a complex intervention (e.g., 'standardized intervention' (12/14); 'the active therapeutic ingredient' (8/15). Overlap of instruments across studies was poor, only instruments on activity endpoints were more homogeneous. The clinical interpretation of observed score changes was mostly missing. CONCLUSION: We found good to fair methodological quality in a considerable number of RCTs on physiotherapy in CP children. Nevertheless, improvement is indicated for certain areas in design and performance of future studies. This review shows that informative RCTs on complex interventions for multifaceted disabilities are feasible.

Cerebral Palsy↗

PubMed1992

In situ hybridisation: a review of methodologies and applications in the biomedical sciences.

In situ hybridisation methodology is reviewed with particular emphasis on the latest modifications of technique. Methodology is evaluated, with suggestions on how to maximise its successful application. Emphasis is placed upon non-radioactive techniques which can be used by morphologically orientated laboratories, and details of the use of digoxigenin-labelled oligonucleotide probes are given special mention. Recent applications in morphology, and neurobiology, virology, pathology and cytogenetics are detailed. Developments where significant advances have been made in the biomedical sciences are highlighted.

DNA↗

PubMed1999

Studies of factors in relapse to alcohol, drug and nicotine use: a critical review of methodologies and findings.

OBJECTIVE: To critically review the methodologies used to study relapse in substance abusers and compare some of the findings these methodologies have produced. METHOD: Representative studies that have used retrospective, prospective, or near real time methodologies to study antecedents or consequences of relapse are presented and the strengths and weaknesses of each methodology are reviewed. Limitations in the ability of substance abusers to accurately report internal states are considered. Degree of convergence in findings across methodologies is examined. RESULTS: Retrospective reports can provide perhaps the most detailed accounts of circumstances and experiences leading up to relapse, but are also more likely to be inaccurate due to the limitations of memory. Prospective studies are less likely to be affected by memory problems, but may not capture factors that immediately precede relapse. The near real time methodology, which uses palm-top computers to gather data, has many advantages over other methodologies, but a number of limitations as well. The two studies in which retrospective reports were directly compared to either prospective or near real time reports yielded mixed results regarding degree of agreement. Findings from several areas of research suggest that some substance abusers may have difficulty recognizing and reporting internal states. CONCLUSIONS: Despite memory problems and other limitations of self-report, all three methodologies have produced findings that implicate negative affect states, increased craving, cognitive factors, interpersonal problems, and lack of coping as factors in relapse. Future relapse studies should make use of all three methodologies to obtain data on relapse and consequences, and steps should be taken to enhance the accuracy of the self-reports that are gathered with each method.

Alcoholism↗

PubMed2005

Bias control in trials of bodywork: a review of methodological issues.

OBJECTIVE: To review and summarize the methodological challenges in clinical trials of bodywork or handson mind-body therapies such as Feldenkrais Method, Alexander Technique, Trager Work, Eutony, Body Awareness Therapy, Breath Therapy, and Rolfing, and to discuss ways these challenges can be addressed. DESIGN: Review and commentary. METHODS: Search of databases PubMed and EMBASE and screening of bibliographies. Published clinical studies were included if they used individual hands-on approaches and a focus on body awareness, and were not based on technical devices. RESULTS: Of the 53 studies identified, 20 fulfilled inclusion criteria. No studies blinded subject to the treatment being given, but 5 used an alternative treatment and blinded participants to differential investigator expectations of efficacy. No study used a credible placebo intervention. No studies reported measures of patient expectations. Patient expectations have been measured in studies of other modalities but not of hands-on mind-body therapies. Options are presented for minimizing investigator and therapist bias and bias from differential patient expectations, and for maintaining some control for nonspecific treatment effects. Practical issues with recruitment and attrition resulting from volunteer bias are addressed. CONCLUSIONS: Rigorous clinical trials of hands-on complementary and alternative therapy interventions are scarce, needed, and feasible. Difficulties with blinding, placebo, and recruitment can be systematically addressed by various methods that minimize the respective biases. The methods suggested here may enhance the rigor of further explanatory trials.

Bias↗

PubMedDate not supplied

Review of calcium methodologies.

A review of calcium methodologies for serum has been described. The analytical systems developed over the past century have been classified as to type beginning with gravimetry and extending to isotope dilution-mass spectrometry by covering all of the commonly used technics which have evolved during that period. Screening and referee procedures are discussed along with comparative sensitivities encountered between atomic absorption spectrophotometry and molecular absorption spectrophotometry. A procedure involving a simple direct reaction for serum calcium using cresolphthalein complexone is recommended in which high blanks are minimized by repressing the ionization of the color reagent on lowering the dielectric constant characteristics of the mixture with dimethylsulfoxide. Reaction characteristics, errors which can be encountered, normal ranges and an interpretative resume are included in its discussion.

Blood Chemical Analysis↗

PubMedDate not supplied

Literature reviews: evolution of a research methodology.

Literature reviews summarise all past research efforts, and because of this, are increasingly being used as a way of addressing the rapid accumulation of health care information. Because reviews, rather than primary research, are now being used as the basis for many health care decisions, it is important that they are conducted with the same rigour of the primary research. To ensure this rigour, the past two decades have seen a progressive evolution in review methodology, to the point where reviews are now considered research in their own right. Despite this development, the standard of many published reviews remains poor. This paper summarises the development of the literature review methodology and discusses some of the implications for nursing.

Bias↗

PubMed1980

Training outcome in liaison psychiatry. Literature review and methodological proposals.

This paper reviews training outcome studies in liaison psychiatry. The author located nine evaluation studies, only four of which were controlled and only two of which included trainee-related patient outcomes. The author suggests a typology of evaluation dimensions with specific methodological proposals which may be useful for future assessment research.

Education, Medical, Continuing↗

PubMed2000

Quality-of-life and behavioral outcome measures in randomized controlled trials of antiepileptic drugs: a systematic review of methodology and reporting standards.

PURPOSE: To review the methodology and use of quality-of-life and behavioral measures used in randomized controlled trials (RCTs) of antiepileptic drugs in patients with epilepsy. METHODS: Trial reports were found by searching a previously developed comprehensive database of epilepsy RCTs and searching through journals by hand. Inclusion and exclusion criteria were applied, and methodological and quality-of-life and behavioral measure data were extracted. RESULTS: There were 52 different measures used in 46 trials, with the Profile of Mood States, the Minnesota Multiphasic Personality Inventory, and the Washington Psychosocial Seizure Inventory being applied the most frequently. Overall, evidence of the reliability, validity, and sensitivity of measures used in populations of people with epilepsy was sparse. There was also little information on the clinical interpretation of the results. CONCLUSION: Our results highlight a consistent failure to apply quality-of-life and behavioral measures in RCTs in a systematic way. We found repeated evidence of researchers' failure to review the use of previous measures and selection of measures without evidence of their appropriateness for use in a population with epilepsy. We recommend the use of quality-of-life and behavioral measures in RCTs with proven psychometric properties in a population with epilepsy.

Adult↗

PubMed1998

Neuropsychological outcomes in randomized controlled trials of antiepileptic drugs: a systematic review of methodology and reporting standards.

PURPOSE: To systematically review the methodology and use of neuropsychological tests in randomized controlled trials (RCTs) of antiepileptic drugs (AEDs) in patients with epilepsy. METHODS: Trial reports were found by searching Medline 1966-1996 and searching through journals by hand. Inclusion and exclusion criteria were applied, and methodological and neuropsychological test data was extracted by using a proforma. RESULTS: 43 reports met our inclusion criteria, representing 40 RCTs. as three RCTs had generated two reports. Twenty-two were actively controlled, and 18 were placebo-controlled studies. Reporting of basic methods such as randomization method was poor. There has been no uniform approach to the use of neuropsychological tests, and a total of 87 has been used. The Stroop Colour Word Test and the Finger Tapping Test were most commonly used, at 13 times each, but were not used or reported in a uniform manner. CONCLUSIONS: Poor reporting of methods and the use of a plethora of neuropsychological tests create great difficulties for anyone wishing to make sense of currently available data. If we are better to understand the neuropsychological effects of AEDs, a more rational approach is needed, for which recommendations are made.

Adult↗

PubMed2002

Is volume related to outcome in health care? A systematic review and methodologic critique of the literature.

PURPOSE: To systematically review the methodologic rigor of the research on volume and outcomes and to summarize the magnitude and significance of the association between them. DATA SOURCES: The authors searched MEDLINE from January 1980 to December 2000 for English-language, population-based studies examining the independent relationship between hospital or physician volume and clinical outcomes. Bibliographies were reviewed to identify other articles of interest, and experts were contacted about missing or unpublished studies. STUDY SELECTION: Of 272 studies reviewed, 135 met inclusion criteria and covered 27 procedures and clinical conditions. DATA EXTRACTION: Two investigators independently reviewed each article, using a standard form to abstract information on key study characteristics and results. DATA SYNTHESIS: The methodologic rigor of the primary studies varied. Few studies used clinical data for risk adjustment or examined effects of hospital and physician volume simultaneously. Overall, 71% of all studies of hospital volume and 69% of studies of physician volume reported statistically significant associations between higher volume and better outcomes. The strongest associations were found for AIDS treatment and for surgery on pancreatic cancer, esophageal cancer, abdominal aortic aneurysms, and pediatric cardiac problems (a median of 3.3 to 13 excess deaths per 100 cases were attributed to low volume). Although statistically significant, the volume-outcome relationship for coronary artery bypass surgery, coronary angioplasty, carotid endarterectomy, other cancer surgery, and orthopedic procedures was of much smaller magnitude. Hospital volume-outcome studies that performed risk adjustment by using clinical data were less likely to report significant associations than were studies that adjusted for risk by using administrative data. CONCLUSIONS: High volume is associated with better outcomes across a wide range of procedures and conditions, but the magnitude of the association varies greatly. The clinical and policy significance of these findings is complicated by the methodologic shortcomings of many studies. Differences in case mix and processes of care between high- and low-volume providers may explain part of the observed relationship between volume and outcome.

Delivery of Health Care↗

PubMed2003

Sexual double standards: a review and methodological critique of two decades of research.

A review of 30 studies published since 1980 found evidence for the continued existence of sexual double standards: different standards of sexual permissiveness for women and men. Experimental studies have included predominantly White North American college students; ethnographies, focus group and interview studies, and linguistic analyses have included more diverse samples. Studies show that sexual double standards are influenced by situational and interpersonal factors (e.g., the target's age, level of relationship commitment, and number of partners), and that double standards are local constructions, differing across ethnic and cultural groups. This review discusses methodological issues, including the strengths and limitations of quantitative and qualitative approaches. It also discusses implications for women s high-risk sexual behavior and sexual identity, and suggests directions for future research.

Adolescent↗

PubMed1997

Relative effects of carbohydrates and protein on satiety -- a review of methodology.

There is some evidence that the effects of carbohydrates and protein may differ with respect to satiety. This may depend in part on the different methods of preparing these nutrients for administration. Additional factors such as timing, different delays, differential metabolism and expectations of ingested foods may contribute to different outcomes of experiments investigating the satiating effects of macronutrients. Here, studies of the relative satiating effects of carbohydrates and protein are discussed followed by a methodological discussion of the reviewed studies. Finally, suggestions for methodological improvements are given which should allow future studies to investigate more clearly the mechanisms underlying satiety.

Animals↗

PubMed2006

Cochrane Skin Group systematic reviews are more methodologically rigorous than other systematic reviews in dermatology.

BACKGROUND: The Cochrane collaboration aims to produce high-quality systematic reviews. It is not known whether the methods used in producing Cochrane Skin Group (CSG) reviews result in higher quality reviews than other systematic reviews in dermatology. OBJECTIVES: To determine how the methodological quality of dermatological CSG reviews published in The Cochrane Library and in peer-reviewed journals compare with non-Cochrane systematic reviews. METHODS: Two blinded investigators independently assessed review quality using the 10-item Oxman and Guyatt scale. RESULTS: Thirty-eight systematic reviews (17 Cochrane reviews published in The Cochrane Library, 11 Cochrane reviews published in peer-reviewed journals and 10 non-Cochrane reviews published in peer-reviewed journals) were examined. The Cochrane Library reviews included quality of life (11/17 vs. 1/10, P = 0.014) and adverse outcomes (14/17 vs. 2/10, P = 0.003) more often than non-Cochrane reviews published in peer-reviewed journals. Cochrane reviews published in both peer-reviewed journals and The Cochrane Library were more likely to include comprehensive search strategies (11/11 and 17/17 vs. 6/10, P-values = 0.04 and 0.01), take steps to minimize selection bias (11/11 and 16/17 vs. 3/10, P-values = 0.003 and 0.001) and appropriately assess the validity of all included trials (10/11 and 16/17 vs. 4/10, P-values = 0.04 and 0.007) than non-Cochrane reviews. Overall, Cochrane reviews published both in peer-reviewed journals and in The Cochrane Library were assigned higher quality scores by reviewers than non-Cochrane reviews (median = 6.0 and 6.5 vs. 4.5, P-values = 0.01 and 0.002). CONCLUSIONS: The Cochrane Library systematic review methodology leads to higher quality reviews on dermatological topics.

Dermatology↗

PubMed2003

HIV sexual risk-reduction interventions for youth: a review and methodological critique of randomized controlled trials.

The authors review and provide a methodological critique of randomized controlled studies of HIV risk reduction interventions that measured sexual risk behavior outcomes with adolescents. Studies conducted in school, community, and health care settings were reviewed. Overall, 13 of 23 interventions (57%) were effective in reducing sexual risk behavior. Methodological strengths of extant studies included an emphasis on a theoretical framework, evaluation of both individualized and group-intervention formats, use of multiple assessments of risk behavior (including biological outcomes), and inclusion of efficacy and effectiveness trials. Methodological limitations included limited evaluation of theoretical mediators of risk reduction, failure to report effect sizes, and lack of sustained findings. Inconsistencies were found in data analytic procedures and reporting, including how nested designs, skewed data, and attrition were addressed. Recommendations for designing methodologically rigorous interventions are provided.

Adolescent↗

PubMed1997

A meta-analysis of the effect of hormone replacement therapy upon depressed mood.

This meta-analysis had two objectives: (a) to aggregate data from studies that used hormone replacement therapy (HRT) and a quantitative measure of depressed mood in order to examine the effectiveness of HRT upon menopausal depressed mood; and (b) to review the methodologies of this literature base. The overall effect size for HRT was 0.68. This indicated that the average treatment patient had lower levels of depressed mood than 76% of the control patients. Analyses of specific hormone treatments suggested that (a) estrogen significantly reduced depressed mood (ES = 0.69); (b) progesterone alone, and in combination with estrogen, was associated with smaller reductions in depressed mood (ES = 0.39, ES = 0.45, respectively); and (c) androgen alone and in combination with estrogen was associated with greater reductions in depressed mood (ES = 1.37; ES = 0.90, respectively). In summary, HRT appeared to be effective in reducing depressed mood among menopausal women. The methodological review indicated that most studies used adequate sample sizes, controlled research designs, random assignment, double-blind treatment manipulations, and valid and reliable measures of depression. Limitations in the interpretation of these results are discussed and recommendations for improved methodology are provided.

Climacteric↗

PubMed1996

Essential and reactive alcoholism: a review.

Methodological characteristics and substantive findings of investigations of essential and reactive alcoholics were reviewed. The data base was comprised of approximately 12 studies published between 1951-1992, most of which employed small samples of hospitalized male alcoholics. Psychometric properties of the Essential-Reactive Alcoholism Questionnaire, the instrument generally used to assess the essential-reactive dimensions, rarely were examined. The weight of the evidence suggests that essential alcoholics have earlier onset and greater severity of alcoholism, lower levels of occupational and educational achievement, more interpersonal conflict, fewer long-term friendships, more antisocial attitudes and conduct, greater density of familial alcoholism, more impaired neuropsychological functioning, and lower resting blood pressure than do reactive alcoholics. Research is needed to assess the prognostic utility of the essential-reactive typology and the degree to which the distinction may facilitate patient-treatment matching.

Alcoholism↗