221 research outputs found

    Comparability of non-destructive moisture measurement techniques on masonry during simulated wetting

    Get PDF
    Detecting the presence of moisture in historical masonry is essential to understanding how a structure interacts with the environment, and diagnosing the potential for damage from a range of physical, chemical, and biological processes. In-situ, non-invasive diagnostic techniques have been developed in preference to methods that require irreversible modifications to a structure. These techniques include: electrical resistivity, microwaves, and infrared thermography. Independently, these approaches provide limited snapshots of surficial and internal moisture regimes; this project sought to assess the comparability of multiple techniques. Simulated post-rain spell drying was monitored over 48 h on limestone and sandstone monoliths in a controlled laboratory environment and also in ambient conditions on purpose-built masonry located in Oxfordshire, UK. Repeat measurements were taken using electrical resistance tomography (ERT), electrical and microwave moisture meters, and infrared thermography. Three aspects of comparability are discussed: i) data transformations and geological comparability, ii) depth-resolving meter readings, iii) the localised benefits of employing multiple technologies and instruments

    Occurrence and adverse effect on outcome of hyperlactatemia in the critically ill

    Get PDF
    Introduction: Hyperlactatemia is frequent in critically ill patients and is often used as a marker of adverse outcome. However, studies to date have focused on selected intensive care unit (ICU) populations. We sought to determine the occurrence and relation of hyperlactatemia with ICU mortality in all patients admitted to four ICUs in a large regional critical care system. Methods: All adults ([greater than or equal to] 18 years) admitted to ICUs in the Calgary Health Region (population 1.2 million) during 2003 to 2006 were included retrospectively. Lactate determinations were at the discretion of the attending service and hyperlactatemia was defined by a lactate level > 2 mmol/L. Results: A total of 13,932 ICU admissions occurred among 11,581 patients. The median age was 63 years (37% female), the mean APACHE II score was 25 ± 9 (n = 13,922). At presentation (within first day of admission), 12,246 patients had at least one lactate determination and the median peak lactate was 1.8 (IQR 1.2 to 2.9) mmol/L. The cumulative incidence of at least one documented episode of hyperlactatemia was 5578/13,932 (40%); 5058 (36%) patients had hyperlactatemia at presentation, and a further 520 (4%) developed hyperlactatemia subsequently. The incidence of hyperlactatemia varied significantly by major admitting diagnostic category (P < 0.001) and was highest among neuro/trauma patients 1053/2328 (45%), followed by medical 2047/4935 (41%), other surgical 900/2274 (40%), and cardiac surgical 1578/4395 (36%). Among a cohort of 9107 first admissions with ICU stay of at least one day, both hyperlactatemia at presentation (712/3634 (20%) vs. 289/5473 (5%); P < 0.001) and its later development (101/379 (27%) vs. 188/5094 (4%); P < 0.001) were associated with significantly increased case fatality rates as compared with patients without elevated lactate. After controlling for confounding effects in multivariable logistic regression analysis, hyperlactatemia was an independent risk factor for death. Conclusions: Hyperlactatemia is common among the critically ill and predicts risk for death.</p

    Capture-mark-recapture to estimate the number of missed articles for systematic reviews in surgery

    Get PDF
    Abstract BACKGROUND: Systematic reviews are an important knowledge synthesis tool, but with new literature available each day, reviewers must balance identifying all relevant literature against timely synthesis. METHODS: This study tested capture-mark-recapture (CMR), an ecology-based technique, to estimate the total number of articles in the literature identified in a systematic review of adult trauma care quality indicators. RESULTS: The systematic review included 40 articles identified from online searches and citation references. The CMR model suggested that 3 (95% confidence interval [CI]: 0 to 6) articles were missed and the database search provided 93% (one-sided 95% CI: R83%) of known articles for inclusion in the systematic review. The search order used for identifying the articles was optimal among the 24 that could have been used. CONCLUSIONS: The CMR technique can be used in systematic reviews in surgery to estimate the closeness to capturing the total body of literature for a specific topic. Ó 2013 Elsevier Inc. All rights reserved. Systematic reviews are increasingly used in surgery to synthesize knowledge so that evidence can inform clinical practice (eg, guideline development). Exhaustive searching in multiple large bibliographic databases is time consuming and resource intensive, but it needs to be efficient so the results are presented before the information becomes outdated. However, this is difficult because the amount of literature that exists on any given topic is unknown. Capture-mark-recapture (CMR) is a technique originating in ecology that has been applied to systematic reviews of randomized controlled trials of interventions in osteoporosis, gastroenterology, and hematology 1-3 to estimate The project was supported by a Synthesis Grant (KRS-91770) from the Canadian Institutes of Health Research. Dr. Stelfox is supported by a New Investigator Award from the Canadian Institutes of Health Research and a Population Health Investigator Award from Alberta Innovates. Funding sources had no role in the design, conduct, or reporting of this study and we are unaware of any conflicts of interest. None of the authors have financial or professional conflicts of interest that would influence the conduct or reporting of this study. Drs. Stelfox, Foster, and Goldsmith had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis. Presented at the Cochrane Canada Symposium May 9, 2012, Winnipeg, Canada. * Corresponding author. The American Journal of Surgery (2013) 206, 439-440 the number of articles in the literature. The technique has not been evaluated in observational studies or surgical studies. We therefore tested CMR to estimate the total number of articles in the literature identified in a systematic review of adult trauma care quality indicators. We performed a scoping review to identify quality indicators for evaluating trauma care 4 and subsequently systematically reviewed the evidence. 5 Horizon estimates (estimated total population of articles) were calculated for full text review and final inclusion using the 4 step CMR technique: (1) capture an initial sample from a population of interest (eg, catch fish in lake); (2) mark the elements in the sample (eg, tag the fish); (3) release the sample back into the population (eg, release tagged fish back into lake); and (4) resample the population (catch fish from same lake to see how many are tagged). Articles found in our 1st database (MEDLINE) were marked as being retrieved from that search and compared with articles retrieved through subsequent searches (eg, Embase was the 2nd database). Articles identified through bibliography reviews were attributed to the originating electronic database. Poisson regression models were used to calculate fitted estimates of the cell counts (number of articles missed) and estimate the total horizon of articles (SAS v 9.2; SAS, Cary, NC). The results of the horizon estimate are shown in We repeated the process for articles selected for inclusion in the systematic review. The final horizon estimate was 43 (40 to 46) articles, representing a difference of 3 (0 to 6) articles between the projected total literature and the number of articles captured (40 articles). Thus, selection of articles for inclusion in the systematic review represents the capture of 93% (87% to 100%) of the estimated pool of available articles. The search order used for identifying the articles was optimal among the 24 that could have been used. CMR is a technique that can be applied to estimate the total number of relevant articles for a given topic. This study demonstrates that CMR can be successfully used for systematic reviews of observational studies in surgery. Future systematic reviews may consider including horizon estimates as possible stopping rules (eg, search until 80% of articles captured) to identify when a sufficient literature search has been completed. CMR may help improve the completeness and efficiency of systematic reviews

    Low-value clinical practices in injury care: a scoping review and expert consultation survey

    Get PDF
    BACKGROUND: Tests and treatments that are not supported by evidence and could expose patients to unnecessary harm, referred to here as low-value clinical practices, consume up to 30% of healthcare resources. Choosing Wisely and other organisations have published lists of clinical practices to be avoided. However, few apply to injury and most are based uniquely on expert consensus. We aimed to identify low-value clinical practices in acute injury care. METHODS: We conducted a scoping review targeting articles, reviews and guidelines that identified low-value clinical practices specific to injury populations. Thirty-six experts rated clinical practices on a 5-point Likert scale from clearly low-value to clearly beneficial. Clinical practices reported as low-value by at least one level I, II or III study and considered clearly or potentially low-value by at least 75% of experts were retained as candidates for low-value injury care. RESULTS: Of 50,695 citations, 815 studies were included and led to the identification of 150 clinical practices. Of these 63 were considered candidates for low-value injury care; 33 in the emergency room, 9 in trauma surgery, 15 in the intensive care unit and 5 in orthopaedics. We also identified 87 'grey zone' practices, which did not meet our criteria for low-value care. CONCLUSIONS: We identified 63 low-value clinical practices in acute injury care that are supported by empirical evidence and expert opinion. Conditional on future research, they represent potential targets for guidelines, overuse metrics and de-implementation interventions. We also identified 87 'grey zone' practices, which may be interesting targets for value-based decision-making. Our study represents an important step towards the de-implementation of low-value clinical practices in injury care. LEVEL OF EVIDENCE: III

    Back to thiazide-diuretics for hypertension: reflections after a decade of irrational prescribing

    Get PDF
    BACKGROUND: Whether newer antihypertensive drugs, such as calcium channel blockers, angiotensin converting enzyme inhibitors and α blockers are more effective than thiazides and β blockers in preventing coronary disease, has been debated for years. DISCUSSION: Recently several trials addressing this issue have been finalised, and they provide a convincing answer: the newer drugs are no better than the older ones. In the largest trial to date (ALLHAT), thiazide-type diuretic was found to offer advantages over newer drugs. The medical community should now be capable of reaching consensus, and recommend thiazides as the first line therapy for the treatment of hypertension. Prescribing physicians, cardiologists, drug companies and health authorities are all partly responsible for the years of irrational prescribing that we have witnessed. SUMMARY: All stakeholders should now contribute in order to achieve what is clearly in the public's interest: implementing the use of thiazides in clinical practice

    Delivering a sustainable trauma management training programme tailored for low-resource settings in East, Central and Southern African countries using a cascading course model

    Get PDF
    Background: Injuries cause five million deaths and 279 Disability Adjusted Life Years (DALYS) each year worldwide. The COSECSA Oxford Orthopaedic Link (COOL) is a multi-country partnership programme that has delivered training in trauma management to nine sub-Saharan countries across a wide-cadre of health-workers using a model of "primary" courses delivered by UK instructors, followed by "cascading" courses led by local faculty. This study examines the impact on knowledge and clinical confidence among health-workers, and compares the performance of "cascading" and "primary" courses delivered in low-resource settings. Methods: Data was collated from 1030 candidates (119 Clinical Officers, 540 Doctors, 260 Nurses and 111 Medical Students) trained over 28 courses (9 "primary" and 19 "cascading" courses) in nine sub-Saharan countries between 2012 and 2013. Knowledge and clinical confidence of candidates were assessed using pre- and post-course MCQs and confidence matrix rating of clinical scenarios. Changes were measured in relation to co-variants of gender, job roles and primary versus cascading courses. Multivariate regression modelling and cost analysis was performed to examine the impact of primary versus cascading courses on candidates' performance. Findings: There was a significant improvement in knowledge (58% to 77%, p < 0.05) and clinical confidence (68% to 90%, p < 0.05) post-course. "Non-doctors" demonstrated a greater improvement in knowledge (22%) and confidence (24%) following the course (p < 0.05). The degree of improvement of MCQ scores differed significantly, with the cascading courses (21%) outperforming primary courses (15%) (p < 0.002). This is further supported by multivariate regression modelling where cascading courses are a strong predictor for improvement in MCQ scores (Coef = 4.83, p < 0.05). Interpretation: Trauma management training of health-workers plays a pivotal role in tackling the ever-growing trauma burden in Africa. Our study suggests cascading PTC courses may be an effective model in delivering trauma training in low-resource settings, however further studies are required to determine its efficacy in improving clinical competence and retention of knowledge and skills in the long term
    corecore