843 resultados para critical review
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PURPOSE To investigate the adequacy of potential sites for insertion of orthodontic mini-implants (OMIs) in the anterior alveolar region (delimited by the first premolars) through a systematic review of studies that used computed tomography (CT) or cone beam CT (CBCT) to assess anatomical hard tissue parameters, such as bone thickness, available space, and bone density. MATERIALS AND METHODS MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews were searched to identify all relevant papers published between 1980 and September 2011. An extensive search strategy was performed that included the key words "computerized (computed) tomography" and "mini-implants." Information was extracted from the eligible articles for three anatomical areas: maxillary anterior buccal, maxillary anterior palatal, and mandibular anterior buccal. Quantitative data obtained for each anatomical variable under study were evaluated qualitatively with a scoring system. RESULTS Of the 790 articles identified by the search, 8 were eligible to be included in the study. The most favorable area for OMI insertion in the anterior maxilla (buccally and palatally) and mandible is between the canine and the first premolar. The best alternative area in the maxilla (buccally) and the mandible is between the lateral incisor and the canine, while in the maxillary palatal area it is between the central incisors or between the lateral incisor and the canine. CONCLUSIONS Although there is considerable heterogeneity among studies, there is a good level of agreement regarding the optimal site for OMI placement in the anterior region among investigations of anatomical hard tissue parameters based on CT or CBCT scans. In this context, the area between the lateral incisor and the first premolar is the most favorable. However, interroot distance seems to be a critical factor that should be evaluated carefully.
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OBJECTIVE To provide a brief introduction into Critical Incident Reporting Systems (CIRS) as used in human medicine, and to report the discussion from a recent panel meeting discussion with 23 equine anaesthetists in preparation for a new CEPEF-4 (Confidential Enquiry into Perioperative Equine Fatalities) study. STUDY DESIGN Moderated group discussions, and review of literature. METHODS The first group discussion focused on the definition of 'preventable critical incidents' and/or 'near misses' in the context of equine anaesthesia. The second group discussion focused on categorizing critical incidents according to an established framework for analysing risk and safety in clinical medicine. RESULTS While critical incidents do occur in equine anaesthesia, no critical incident reporting system including systematic collection and analysis of critical incidents is in place. CONCLUSIONS AND CLINICAL RELEVANCE Critical incident reporting systems could be used to improve safety in equine anaesthesia - in addition to other study types such as mortality studies.
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BACKGROUND The effectiveness and durability of endovascular revascularization therapies for chronic critical limb ischemia (CLI) are challenged by the extensive burden of infrapopliteal arterial disease and lesion-related characteristics (e.g., severe calcification, chronic total occlusions), which frequently result in poor clinical outcomes. While infrapopliteal vessel patency directly affects pain relief and wound healing, sustained patency and extravascular care both contribute to the ultimate "patient-centric" outcomes of functional limb preservation, mobility and quality of life (QoL). METHODS/DESIGN IN.PACT DEEP is a 2:1 randomized controlled trial designed to assess the efficacy and safety of infrapopliteal arterial revascularization between the IN.PACT Amphirion™ paclitaxel drug-eluting balloon (IA-DEB) and standard balloon angioplasty (PTA) in patients with Rutherford Class 4-5-6 CLI. DISCUSSION This multicenter trial has enrolled 358 patients at 13 European centers with independent angiographic core lab adjudication of the primary efficacy endpoint of target lesion late luminal loss (LLL) and clinically driven target lesion revascularization (TLR) in major amputation-free surviving patients through 12-months. An independent wound core lab will evaluate all ischemic wounds to assess the extent of healing and time to healing at 1, 6, and 12 months. A QoL questionnaire including a pain scale will assess changes from baseline scores through 12 months. A Clinical Events Committee and Data Safety Monitoring Board will adjudicate the composite primary safety endpoints of all-cause death, major amputation, and clinically driven TLR at 6 months and other trial endpoints and supervise patient safety throughout the study. All patients will be followed for 5 years. A literature review is presented of the current status of endovascular treatment of CLI with drug-eluting balloon and standard PTA. The rationale and design of the IN.PACT DEEP Trial are discussed. IN.PACT DEEP is a milestone, prospective, randomized, robust, independent core lab-adjudicated CLI trial that will evaluate the role of a new infrapopliteal revascularization technology, the IA-DEB, compared to PTA. It will assess the overall impact on infrapopliteal artery patency, limb salvage, wound healing, pain control, QoL, and patient mobility. The 1-year results of the adjudicated co-primary and secondary endpoints will be available in 2014. TRIAL REGISTRATION NCT00941733
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Purpose – A growing body of literature points to the importance of public service motivation (PSM) for the performance of public organizations. The purpose of this paper is to assess the method predominantly used for studying this linkage by comparing the findings it yields without and with a correction suggested by Brewer (2006), which removes the common-method bias arising from employee-specific response tendencies. Design/methodology/approach – First, the authors conduct a systematic review of published empirical research on the effects of PSM on performance and show that all studies found have been conducted at the individual level. Performance indicators in all but three studies were obtained by surveying the same employees who were also asked about their PSM. Second, the authors conduct an empirical analysis. Using survey data from 240 organizational units within the Swiss federal government, the paper compares results from an individual-level analysis (comparable to existing research) to two analyses where the data are aggregated to the organizational level, one without and one with the correction for common-method bias suggested by Brewer (2006). Findings – Looking at the Attraction to Policy-Making dimension of PSM, there is an interesting contrast: While this variable is positively correlated with performance in both the individual-level analysis and the aggregated data analysis without the correction for common-method bias, it is not statistically associated with performance in the aggregated data analysis with the correction. Originality/value – The analysis is the first to assess the robustness of the performance-PSM linkage to a correction for common-method bias. The findings place the validity of at least one part of the individual-level linkage between PSM and performance into question.
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Mutualism with our intestinal microbiota is a prerequisite for healthy existence. This requires physical separation of the majority of the microbiota from the host (by secreted antimicrobials, mucus, and the intestinal epithelium) and active immune control of the low numbers of microbes that overcome these physical and chemical barriers, even in healthy individuals. In this review, we address how B-cell responses to members of the intestinal microbiota form a robust network with mucus, epithelial integrity, follicular helper T cells, innate immunity, and gut-associated lymphoid tissues to maintain host-microbiota mutualism.
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We explore a method developed in statistical physics which has been argued to have exponentially small finite-volume effects, in order to determine the critical temperature Tc of pure SU(3) gauge theory close to the continuum limit. The method allows us to estimate the critical coupling βc of the Wilson action for temporal extents up to Nτ∼20 with ≲0.1% uncertainties. Making use of the scale setting parameters r0 and t0−−√ in the same range of β-values, these results lead to the independent continuum extrapolations Tcr0=0.7457(45) and Tct0−−√=0.2489(14), with the latter originating from a more convincing fit. Inserting a conversion of r0 from literature (unfortunately with much larger errors) yields Tc/ΛMS¯¯¯¯¯=1.24(10).
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OBJECTIVES: To (1) review the development and medical applications of hydroxyethyl starch (HES) solutions with particular emphasis on its physiochemical properties; (2) critically appraise the available evidence in human and veterinary medicine, and (3) evaluate the potential risks and benefits associated with their use in critically ill small animals. DATA SOURCES: Human and veterinary original research articles, scientific reviews, and textbook sources from 1950 to the present. HUMAN DATA SYNTHESIS: HES solutions have been used extensively in people for over 30 years and ever since its introduction there has been a great deal of debate over its safety and efficacy. Recently, results of seminal trials and meta-analyses showing increased risks related to kidney dysfunction and mortality in septic and critically ill patients, have led to the restriction of HES use in these patient populations by European regulatory authorities. Although the initial ban on the use of HES in Europe has been eased, proof regarding the benefits and safety profile of HES in trauma and surgical patient populations has been requested by these same European regulatory authorities. VETERINARY DATA SYNTHESIS: The veterinary literature is limited mostly to experimental studies and clinical investigations with small populations of patients with short-term end points and there is insufficient evidence to generate recommendations. CONCLUSIONS: Currently, there are no consensus recommendations regarding the use of HES in veterinary medicine. Veterinarians and institutions affected by the HES restrictions have had to critically reassess the risks and benefits related to HES usage based on the available information and sometimes adapt their procedures and policies based on their reassessment. Meanwhile, large, prospective, randomized veterinary studies evaluating HES use are needed to achieve relevant levels of evidence to enable formulation of specific veterinary guidelines.
Keeping bugs in check: The mucus layer as a critical component in maintaining intestinal homeostasis
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In the mammalian gastrointestinal tract the close vicinity of abundant immune effector cells and trillions of commensal microbes requires sophisticated barrier and regulatory mechanisms to maintain vital host-microbial interactions and tissue homeostasis. During co-evolution of the host and its intestinal microbiota a protective multilayered barrier system was established to segregate the luminal microbes from the intestinal mucosa with its potent immune effector cells, limit bacterial translocation into host tissues to prevent tissue damage, while ensuring the vital functions of the intestinal mucosa and the luminal gut microbiota. In the present review we will focus on the different layers of protection in the intestinal tract that allow the successful mutualism between the microbiota and the potent effector cells of the intestinal innate and adaptive immune system. In particular, we will review some of the recent findings on the vital functions of the mucus layer and its site-specific adaptations to the changing quantities and complexities of the microbiota along the (gastro-) intestinal tract. Understanding the regulatory pathways that control the establishment of the mucus layer, but also its degradation during intestinal inflammation may be critical for designing novel strategies aimed at maintaining local tissue homeostasis and supporting remission from relapsing intestinal inflammation in patients with inflammatory bowel diseases.
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OBJECTIVES Randomized clinical trials that enroll patients in critical or emergency care (acute care) setting are challenging because of narrow time windows for recruitment and the inability of many patients to provide informed consent. To assess the extent that recruitment challenges lead to randomized clinical trial discontinuation, we compared the discontinuation of acute care and nonacute care randomized clinical trials. DESIGN Retrospective cohort of 894 randomized clinical trials approved by six institutional review boards in Switzerland, Germany, and Canada between 2000 and 2003. SETTING Randomized clinical trials involving patients in an acute or nonacute care setting. SUBJECTS AND INTERVENTIONS We recorded trial characteristics, self-reported trial discontinuation, and self-reported reasons for discontinuation from protocols, corresponding publications, institutional review board files, and a survey of investigators. MEASUREMENTS AND MAIN RESULTS Of 894 randomized clinical trials, 64 (7%) were acute care randomized clinical trials (29 critical care and 35 emergency care). Compared with the 830 nonacute care randomized clinical trials, acute care randomized clinical trials were more frequently discontinued (28 of 64, 44% vs 221 of 830, 27%; p = 0.004). Slow recruitment was the most frequent reason for discontinuation, both in acute care (13 of 64, 20%) and in nonacute care randomized clinical trials (7 of 64, 11%). Logistic regression analyses suggested the acute care setting as an independent risk factor for randomized clinical trial discontinuation specifically as a result of slow recruitment (odds ratio, 4.00; 95% CI, 1.72-9.31) after adjusting for other established risk factors, including nonindustry sponsorship and small sample size. CONCLUSIONS Acute care randomized clinical trials are more vulnerable to premature discontinuation than nonacute care randomized clinical trials and have an approximately four-fold higher risk of discontinuation due to slow recruitment. These results highlight the need for strategies to reliably prevent and resolve slow patient recruitment in randomized clinical trials conducted in the critical and emergency care setting.
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BACKGROUND Evidence suggests that EMS-physician-guided cardiopulmonary resuscitation (CPR) in out-of-hospital cardiac arrest (OOHCA) may be associated with improved outcomes, yet randomized controlled trials are not available. The goal of this meta-analysis was to determine the association between EMS-physician- versus paramedic-guided CPR and survival after OOHCA. METHODS AND RESULTS Studies that compared EMS-physician- versus paramedic-guided CPR in OOHCA published until June 2014 were systematically searched in MEDLINE, EMBASE and Cochrane databases. All studies were required to contain survival data. Data on study characteristics, methods, and as well as survival outcomes were extracted. A random-effects model was used for the meta-analysis due to a high degree of heterogeneity among the studies (I (2) = 44 %). Return of spontaneous circulation [ROSC], survival to hospital admission, and survival to hospital discharge were the outcome measures. Out of 3,385 potentially eligible studies, 14 met the inclusion criteria. In the pooled analysis (n = 126,829), EMS-physician-guided CPR was associated with significantly improved outcomes compared to paramedic-guided CPR: ROSC 36.2 % (95 % confidence interval [CI] 31.0 - 41.7 %) vs. 23.4 % (95 % CI 18.5 - 29.2 %) (pooled odds ratio [OR] 1.89, 95 % CI 1.36 - 2.63, p < 0.001); survival to hospital admission 30.1 % (95 % CI 24.2 - 36.7 %) vs. 19.2 % (95 % CI 12.7 - 28.1 %) (pooled OR 1.78, 95 % CI 0.97 - 3.28, p = 0.06); and survival to discharge 15.1 % (95 % CI 14.6 - 15.7 %) vs. 8.4 % (95 % CI 8.2 - 8.5 %) (pooled OR 2.03, 95 % CI 1.48 - 2.79, p < 0.001). CONCLUSIONS This systematic review suggests that EMS-physician-guided CPR in out-of-hospital cardiac arrest is associated with improved survival outcomes.
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Institutional Review Boards (IRBs) are the primary gatekeepers for the protection of ethical standards of federally regulated research on human subjects in this country. This paper focuses on what general, broad measures that may be instituted or enhanced to exemplify a "model IRB". This is done by examining the current regulatory standards of federally regulated IRBs, not private or commercial boards, and how many of those standards have been found either inadequate or not generally understood or followed. The analysis includes suggestions on how to bring about changes in order to make the IRB process more efficient, less subject to litigation, and create standardized educational protocols for members. The paper also considers how to include better oversight for multi-center research, increased centralization of IRBs, utilization of Data Safety Monitoring Boards when necessary, payment for research protocol review, voluntary accreditation, and the institution of evaluation/quality assurance programs. ^ This is a policy study utilizing secondary analysis of publicly available data. Therefore, the research for this paper focuses on scholarly medical/legal journals, web information from the Department of Health and Human Services, Federal Drug Administration, and the Office of the Inspector General, Accreditation Programs, law review articles, and current regulations applicable to the relevant portions of the paper. ^ Two issues are found to be consistently cited by the literature as major concerns. One is a need for basic, standardized educational requirements across all IRBs and its members, and secondly, much stricter and more informed management of continuing research. There is no federally regulated formal education system currently in place for IRB members, except for certain NIH-based trials. Also, IRBs are not keeping up with research once a study has begun, and although regulated to do so, it does not appear to be a great priority. This is the area most in danger of increased litigation. Other issues such as voluntary accreditation and outcomes evaluation are slowing gaining steam as the processes are becoming more available and more sought after, such as JCAHO accrediting of hospitals. ^ Adopting the principles discussed in this paper should promote better use of a local IRBs time, money, and expertise for protecting the vulnerable population in their care. Without further improvements to the system, there is concern that private and commercial IRBs will attempt to create a monopoly on much of the clinical research in the future as they are not as heavily regulated and can therefore offer companies quicker and more convenient reviews. IRBs need to consider the advantages of charging for their unique and important services as a cost of doing business. More importantly, there must be a minimum standard of education for all IRB members in the area of the ethical standards of human research and a greater emphasis placed on the follow-up of ongoing research as this is the most critical time for study participants and may soon lead to the largest area for litigation. Additionally, there should be a centralized IRB for multi-site trials or a study website with important information affecting the trial in real time. There needs to be development of standards and metrics to assess the performance of the IRBs for quality assurance and outcome evaluations. The boards should not be content to run the business of human subjects' research without determining how well that function is actually being carried out. It is important that federally regulated IRBs provide excellence in human research and promote those values most important to the public at large.^
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Context. The high prevalence of diabetes among Hispanics in the U.S. has stimulated increased interest in the role culture plays in Hispanics' risk of diabetes. It is critical to identify gaps in the existing research and to determine the relationship between acculturation and diabetes prevalence in the Hispanic population. ^ Objective. To review the current literature to evaluate the effects of acculturation on diabetes prevalence among Hispanic Americans. ^ Methods. A literature search of diabetes-related studies was conducted. Studies were selected for review if they reported at least one acculturation measure, used Hispanics adults (ages 18 and older) and included information regarding the diabetes prevalence of Hispanics and/or Latinos. Only those that examined acculturation by diabetes prevalence for Hispanics were included in the review. ^ Results. Sixteen studies were reviewed that met the search criteria and these studies used distinct measures of acculturation that captured four primary dimensions: time (duration of exposure to U.S. culture), language, culture and residence. Data represented studies conducted in a variety of settings, such as healthcare facilities in a state or region of the U.S. and nationally representative surveys. The data indicate positive, negative and no significant relationship with diabetes. Depending on the measure of acculturation used and gender the association between acculturation and diabetes varied. ^ Conclusions. There is no clear association between acculturation and diabetes prevalence; it can not be determined based on the available literature. Many of the studies examining this relationship found non-significant results and the directionality of the relationship varied greatly depending on the type of measure used, the number of measures used, and the study population. Ideal studies of acculturation should concentrate on investigating the links between time measures of acculturation, location of residence and changing beliefs, values and norms. A comprehensive acculturation scale is needed to better understand the complex relationship between diabetes prevalence amongst Hispanics and acculturation. ^
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Objective. To systematically review studies published in English on the relationship between plasma total homocysteine (Hcy) levels and the clinical and/or postmortem diagnosis of Alzheimer's disease (AD) in subjects who are over 60 years old.^ Method. Medline, PubMed, PsycINFO and Academic Search Premier, were searched by using the keywords "homocysteine", "Alzheimer disease" and "dementia", and "cognitive disorders". In addition, relevant articles in PubMed using the "related articles" link and by cross-referencing were identified. The study design, study setting and study population, sample size, the diagnostic criteria of the National Institute of Neurological and Communicative Disorders and Stroke (NINCDS) and the Alzheimer's Disease and Related Disorders Association (ADRDA), and description of how Hcy levels were measured or defined had to have been clearly stated. Empirical investigations reporting quantitative data on the epidemiology of the relationship between plasma total Hcy (exposure factor) and AD (outcome) were included in the systematic review.^ Results. A total of 7 studies, which included a total of 2,989 subjects, out of 388 potential articles met the inclusion criteria: four case control and three cohort studies were identified. All 7 studies had association statistics, such as the odds ratio (OR), the relative rates (RR), and the hazard ratio (HR) of AD, examined using multivariate and logistic regression analyses. Three case - comparison studies: Clarke et al. (1998) (OR: 4.5, 95% CI.: 2.2 - 9.2); McIlroy et al. (2002) (OR: 2.9, 95% CI.: 1.00–8.1); Quadri et al. (2004) (OR: 3.7, 95% CI.: 1.1 - 13.1), and two cohort studies: Seshadri et al. (2002) (RR: 1.8, 95% CI.: 1.3 - 2.5); Ravaglia et al. (2005) (HR: 2.1, 95% CI.: 1.7 - 3.8) found a significant association between serum total Hcy and AD. One case-comparison study, Miller et al. (2002) (OR: 2.2, 95% C.I.: 0.3 -16), and one cohort study, Luchsinger et al. (2004) (HR: 1.4, 95% C.I.: 0.7 - 2.3) failed to reject H0.^ Conclusions. The purpose of this review is to provide a thorough analysis of studies that examined the relationship between Hcy levels and AD. Five studies showed a positive statistically significant association between elevated total Hcy values and AD but the association was not statistically significant in two studies. Further research is needed in order to establish evidence of the strong, consistent association between serum total Hcy and AD as well as the presence of the appropriate temporal relationship. To answer these questions, it is important to conduct more prospective studies that examine the occurrence of AD in individuals with and without elevated Hcy values at baseline. In addition, the international standardization of measurements and cut-off points for plasma Hcy levels across laboratories is a critical issue to be addressed for the conduct of future studies on the topic.^
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A review of existing literature revealed at least two distinct theoretical perspectives or schools of thought which are troubled by problems of the lack of participation in the workplace: Jurgen Habermas' ideal of communicative rationality (1984; 1987); and the field of workplace democracy. Whereas Habermas' ideal of communicative rationality establishes communication as necessary to attain a democratic workplace, the ideal of workplace democracy focuses on a participatory ideal in which conditions of open participation must be fulfilled in order to attain a democratic workplace. This study compared the strengths and weaknesses of the conditions proposed by Habermas with the strengths and weaknesses of the conditions selected to represent the workplace democracy ideal. Two incidents were selected for analysis which occurred within a period of one year within one large healthcare organization. The author was present as a participant-observer to assess these incidents. Each of the conditions for the ideal of communicative rationality and for the workplace democracy ideal was systematically applied to both incidents selected for analysis. The results of the analysis suggested that application of Habermas' theory provided more insight into potential distortions in communication than did the conditions selected to represent workplace democracy. Although the conditions of both models were frequently complementary and even overlapping at times, application of each theory to the same incident produced distinctly different results. ^
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Context: Black women are reported to have a higher prevalence of uterine fibroids, and a threefold higher incidence rate and relative risk for clinical uterine fibroid development as compared to women of other races. Uterine fibroid research has reported that black women experience greater uterine fibroid morbidity and disproportionate uterine fibroid disease burden. With increased interest in understanding uterine fibroid development, and race being a critical component of uterine fibroid assessment, it is imperative that the methods used to determine the race of research participants is defined and the operational definition of the use of race as a variable is reported for methodological guidance, and to enable the research community to compare statistical data and replicate studies. ^ Objectives: To systematically review and evaluate the methods used to assess race and racial disparities in uterine fibroid research. ^ Data Sources: Databases searched for this review include: OVID Medline, NML PubMed, Ebscohost Cumulative Index to Nursing and Allied Health Plus with Full Text, and Elsevier Scopus. ^ Review Methods: Articles published in English were retrieved from data sources between January 2011 and March 2011. Broad search terms, uterine fibroids and race, were employed to retrieve a comprehensive list of citations for review screening. The initial database yield included 947 articles, after duplicate extraction 485 articles remained. In addition, 771 bibliographic citations were reviewed to identify additional articles not found through the primary database search, of which 17 new articles were included. In the first screening, 502 titles and abstracts were screened against eligibility questions to determine citations of exclusion and to retrieve full text articles for review. In the second screening, 197 full texted articles were screened against eligibility questions to determine whether or not they met full inclusion/exclusion criteria. ^ Results: 100 articles met inclusion criteria and were used in the results of this systematic review. The evidence suggested that black women have a higher prevalence of uterine fibroids when compared to white women. None of the 14 studies reporting data on prevalence reported an operational definition or conceptual framework for the use of race. There were a limited number of studies reporting on the prevalence of risk factors among racial subgroups. Of the 3 studies, 2 studies reported prevalence of risk factors lower for black women than other races, which was contrary to hypothesis. And, of the three studies reporting on prevalence of risk factors among racial subgroups, none of them reported a conceptual framework for the use of race. ^ Conclusion: In the 100 uterine fibroid studies included in this review over half, 66%, reported a specific objective to assess and recruit study participants based upon their race and/or ethnicity, but most, 51%, failed to report a method of determining the actual race of the participants, and far fewer, 4% (only four South American studies), reported a conceptual framework and/or operational definition of race as a variable. However, most, 95%, of all studies reported race-based health outcomes. The inadequate methodological guidance on the use of race in uterine fibroid studies, purporting to assess race and racial disparities, may be a primary reason that uterine fibroid research continues to report racial disparities, but fails to understand the high prevalence and increased exposures among African-American women. A standardized method of assessing race throughout uterine fibroid research would appear to be helpful in elucidating what race is actually measuring, and the risk of exposures for that measurement. ^