2,038 research outputs found

    Classification and concept consistency

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    This article investigates the extent to which undergraduates consistently use a single mechanism as a basis for classifying mathematical objects. We argue that the concept image/concept definition distinction focuses on whether students use an accepted definition but does not necessarily capture the more basic notion that there should be a fixed basis for classification. We examine students’ classifications of real sequences before and after exposure to definitions of increasing and decreasing; we develop an abductive plausible explanations method to estimate the consistency within the participants’ responses and suggest that this provides evidence that many students may lack what we call concept consistency

    Removal of emerging pollutants in conventional and microalgae based biotechnology urban wastewater treatment plants

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    Wastewater treatment plants (WWTPs) reduce portion of the input of pharmaceuticals in aquatic systems, but there is no data available about the elimination of emerging contaminants with microalgae technology. The aim of this work was to determine the average mass flows and concentrations of pharmaceuticals in influents and effluents from two sewages treatment plants using conventional and microalgae based biotechnologies and to compare the removal of pharmaceuticals using both depuration technologies. Only between 20 to 60% of five pharmaceuticals groups is reduce in both WWTP using conventional technologies consisting of a pretreatment, primary settling and secondary treatment by aerobic biological reactor. Using microalgae based biotechnologies efficiency of removal pharmaceuticals is higher than conventional technologies and it increase by using DAF (Dissolve Air Flotation) technology to separate algae biomass

    The 18-Year Risk of Cancer, Angioedema, Insomnia, Depression, and Erectile Dysfunction in Association With Antihypertensive Drugs: Post-Trial Analyses From ALLHAT-Medicare Linked Data

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    PURPOSE: This study aimed to determine the 18-year risk of cancer, angioedema, insomnia, depression, and erectile dysfunction in association with antihypertensive drug use. METHODS: This is a post-trial passive follow-up study of Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants between 1994 and 1998 that was conducted by linking their follow-up data with Medicare claims data until 2017 of subjects who were free of outcomes at baseline on 1 January 1999. The main outcomes were the occurrence of cancer (among RESULTS: The 18-year cumulative incidence rate of cancer other than non-melanoma skin cancer from Medicare inpatient claims was 23.9% for chlorthalidone, 23.4% for amlodipine, and 25.3% for lisinopril. There were no statistically significant differences in the 18-year risk of cancer, depression, and erectile dysfunction among the three drugs based on the adjusted hazard ratios. The adjusted 18-year risk of angioedema was elevated in those receiving lisinopril than in those receiving amlodipine (hazard ratio: 1.63, 95% CI: 1.14-2.33) or in those receiving chlorthalidone (1.33, 1.00-1.79), whereas the adjusted 18-year risk of insomnia was statistically significantly decreased in those receiving lisinopril than in those receiving amlodipine (0.90, 0.81-1.00). CONCLUSIONS: The 18-year risk of angioedema was significantly higher in patients receiving lisinopril than in those receiving amlodipine or chlorthalidone; the risk of insomnia was significantly lower in patients receiving lisinopril than in those receiving amlodipine; and the risk of cancer, depression, and erectile dysfunction (in men) was not statistically significantly different among the three drug groups

    Risk of Developing alzheimer\u27s Disease and Related Dementias in allhat Trial Participants Receiving Diuretic, ace-inhibitor, or Calcium-Channel Blocker With 18 Years of Follow-Up

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    BACKGROUND: There is no any large randomized clinical trial of antihypertensive drug treatment with 18-year passive follow-up to examine the risk of Alzheimer\u27s Disease (AD) or Related Dementias (ADRD). METHODS: Post-trial passive follow-up study of Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants in 1994-1998 by linking with their Medicare claims data through 2017 among 17,158 subjects in 567 U.S. centers who were free of ADRD at baseline on January 1, 1999. Main outcome was the occurrence of ADRD over 18 years of follow-up. RESULTS: The 18-year cumulative incidence rates were 30.9% for AD, 59.2% for non-AD dementias, and 60.9% for any ADRD. The 18-year cumulative incidence of AD was almost identical for the 3 drug groups (30.5% for chlorthalidone, 31.1% for amlodipine, and 31.4% for lisinopril). The hazard ratios of AD, non-AD dementias and total ADRD were not statistically significantly different among the 3 drug groups. The adjusted hazard ratio of AD was 1.04 (95% CI: 0.94-1.14) for chlorthalidone CONCLUSION: The risk of ADRD did not vary significantly by 3 antihypertensive drugs in ALLHAT trial participants with 18-years of follow-up. The risk of ADRD was significantly associated with age, gender, race/ethnicity, education, and history of vascular diseases

    Mortality and Morbidity among individuals With Hypertension Receiving a Diuretic, ace inhibitor, or Calcium Channel Blocker: a Secondary analysis of a Randomized Clinical Trial

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    IMPORTANCE: The long-term relative risk of antihypertensive treatments with regard to mortality and morbidity is not well understood. OBJECTIVE: to determine the long-term posttrial risk of primary and secondary outcomes among trial participants who were randomized to either a thiazide-type diuretic, calcium channel blocker (CCB), or angiotensin-converting enzyme (ACE) inhibitor with up to 23 years of follow-up. DESIGN, SETTING, AND PARTICIPANTS: This prespecified secondary analysis of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT), a multicenter randomized, double-blind, active-controlled clinical trial, followed up with participants aged 55 years or older with a diagnosis of hypertension and at least 1 other coronary heart disease risk factor for up to 23 years, from February 23, 1994, to December 31, 2017. Trial participants were linked with administrative databases for posttrial mortality (N = 32 804) and morbidity outcomes (n = 22 754). Statistical analysis was performed from January 2022 to October 2023. INTERVENTIONS: Participants were randomly assigned to receive a thiazide-type diuretic (n = 15 002), a CCB (n = 8898), or an ACE inhibitor (n = 8904) for planned in-trial follow-up of approximately 4 to 8 years and posttrial passive follow-up for up to 23 years. MAIN OUTCOMES AND MEASURES: The primary end point was mortality due to cardiovascular disease (CVD). Secondary outcomes included all-cause mortality, combined fatal and nonfatal (morbidity) CVD, and both mortality and morbidity for coronary heart disease, stroke, heart failure, end-stage renal disease, and cancer. RESULTS: A total of 32 804 participants (mean [SD] age, 66.9 [7.7] years; 17 411 men [53.1%]; and 11 772 Black participants [35.9%]) were followed up for all-cause mortality and a subgroup of 22 754 participants (mean [SD] age, 68.7 [7.2] years; 12 772 women [56.1%]; and 8199 Black participants [36.0%]) were followed up for fatal or nonfatal CVD through 2017 (mean [SD] follow-up, 13.7 [6.7] years; maximum follow-up, 23.9 years). Cardiovascular disease mortality rates per 100 persons were 23.7, 21.6, and 23.8 in the diuretic, CCB, and ACE inhibitor groups, respectively, at 23 years after randomization (adjusted hazard ratio [AHR], 0.97 [95% CI, 0.89-1.05] for CCB vs diuretic; AHR, 1.06 [95% CI, 0.97-1.15] for ACE inhibitor vs diuretic). The long-term risks of most secondary outcomes were similar among the 3 groups. Compared with the diuretic group, the ACE inhibitor group had a 19% increased risk of stroke mortality (AHR, 1.19 [95% CI, 1.03-1.37]) and an 11% increased risk of combined fatal and nonfatal hospitalized stroke (AHR, 1.11 [95% CI, 1.03-1.20]). CONCLUSIONS AND RELEVANCE: In this secondary analysis of a randomized clinical trial in an adult population with hypertension and coronary heart disease risk factors, CVD mortality was similar between all 3 groups. ACE inhibitors increased the risk of stroke outcomes by 11% compared with diuretics, and this effect persisted well beyond the trial period. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00000542

    Lack of a significant legacy effect of baseline blood pressure 'treatment naivety' on all-cause and cardiovascular mortality in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial

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    Objectives: To investigate legacy effects at 14-year follow-up of all-cause and cardiovascular disease (CVD) mortality in 'treatment-naive' or 'previous treatment' groups based on blood pressure (BP)-lowering treatment status at baseline. Methods: A post-hoc observational study of the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial. We excluded participants with a previous history of CVD events. Cox proportional hazard model and 95% confidence interval were used to estimate the effects of treatment naive on mortality outcomes. Moreover, a subgroup analysis by estimated 10-year Framingham risk score was performed. Results: In multivariable models adjusting for baseline and in-trial characteristics (BP values and number of BP medications as time-dependent variables), there was no statistically significant difference in 5 and 14-year all-cause mortality with a hazard ratio of 0.93 (95% confidence interval 0.80-1.09) and hazard ratio 0.95 (0.88-1.03) and in 5 and 14-year CVD mortality hazard ratio 0.94 (0.72-1.23) and hazard ratio 0.93 (0.80-1.08). In subgroup by absolute CVD risk, no heterogeneity of the association between treatment naive and short-term or long-term all-cause or CVD mortality were found. All comparisons are between the treatment-naive and previous treatment groups. Conclusion: Physicians are concerned about 'legacy effects' of not treating individuals with a BP of 140 mmHg or over and low absolute risk. When treatment intensification was taken into consideration in the primary prevention population in this study, no adverse legacy effect as a result of baseline BP 'treatment naivety' was evident in 14 years of follow-up. The nonsignificant associations were consistent across the CVD risk subgroups. However, the results may be biased due to unobserved residual confounding and therefore should be interpreted with caution

    How are patients with rare diseases and their carers in the UK impacted by the way care is coordinated? An exploratory qualitative interview study.

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    BACKGROUND: Care coordination is considered important for patients with rare conditions, yet research addressing the impact of care coordination is limited. This study aimed to explore how care coordination (or lack of) impacts on patients and carers. Semi-structured interviews were conducted with 15 patients and carers/parents in the UK, representing a range of rare conditions (including undiagnosed conditions). Transcripts were analysed thematically in an iterative process. RESULTS: Participants described a range of experiences and views in relation to care coordination. Reports of uncoordinated care emerged: appointments were uncoordinated, communication between key stakeholders was ineffective, patients and carers were required to coordinate their own care, and care was not coordinated to meet the changing needs of patients in different scenarios. As a result, participants experienced an additional burden and barriers/delays to accessing care. The impacts described by patients and carers, either attributed to or exacerbated by uncoordinated care, included: impact on physical health (including fatigue), financial impact (including loss of earnings and travel costs), and psychosocial impact (including disruption to school, work and emotional burden). Overall data highlight the importance of flexible care, which meets individual needs throughout patients'/carers' journeys. Specifically, study participants suggested that the impacts may be addressed by: having support from a professional to coordinate care, changing the approach of clinics and appointments (where they take place, which professionals/services are available and how they are scheduled), and improving communication through the use of technology, care plans, accessible points of contact and multi-disciplinary team working. CONCLUSION: This study provides further evidence of impacts of uncoordinated care; these may be complex and influenced by a number of factors. Approaches to coordination which improve access to care and lessen the time and burden placed on patients and carers may be particularly beneficial. Findings should influence future service developments (and the evaluation of such developments). This will be achieved, in the first instance, by informing the CONCORD Study in the UK

    Development of models of care coordination for rare conditions: a qualitative study.

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    INTRODUCTION: Improving care coordination for people with rare conditions may help to reduce burden on patients and carers and improve the care that patients receive. We recently developed a taxonomy of different ways of coordinating care for rare conditions. It is not yet known which models of care coordination are appropriate in different situations. This study aimed to: (1) explore what types of care coordination may be appropriate in different situations, and (2) use these findings to develop hypothetical models of care coordination for rare conditions. METHODS: To explore appropriateness of different types of care coordination, we conducted interviews (n = 30), four focus groups (n = 22) and two workshops (n = 27) with patients, carers, healthcare professionals, commissioners, and charity representatives. Participants were asked about preferences, benefits and challenges, and the factors influencing coordination. Thematic analysis was used to develop hypothetical models of care coordination. Models were refined following feedback from workshop participants. RESULTS: Stakeholders prefer models of care that: are nationally centralised or a hybrid of national and local care, involve professionals collaborating to deliver care, have clear roles and responsibilities outlined (including administrative, coordinator, clinical and charity roles), provide access to records and offer flexible appointments (in terms of timing and mode). Many factors influenced coordination, including those relating to the patient (e.g., condition complexity, patient's location and ability to coordinate their own care), the healthcare professional (e.g., knowledge and time), the healthcare environment (e.g., resources) and societal factors (e.g., availability of funding). We developed and refined ten illustrative hypothetical models of care coordination for rare conditions. CONCLUSION: Findings underline that different models of care coordination may be appropriate in different situations. It is possible to develop models of care coordination which are tailored to the individual in context. Findings may be used to facilitate planning around which models of care coordination may be appropriate in different services or circumstances. Findings may also be used by key stakeholders (e.g. patient organisations, clinicians and service planners) as a decision-making tool
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