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PubMed2006

Daily consumption for six weeks of a lignan complex isolated from flaxseed does not affect endothelial function in healthy postmenopausal women.

The occurrence of menopause is associated with an increased risk of cardiovascular events, and this has partly been attributed to the decline in circulating levels of estrogen. A lignan complex rich in the plant lignan secoisolariciresinol diglucoside (SDG) was isolated from flaxseed. SDG is metabolized by the colonic microflora to the mammalian lignans enterodiol and enterolactone and is hypothesized to be cardioprotective due to their structural similarity to estrogen. The aim of this study was to investigate the effect of a lignan complex, providing 500 mg/d of SDG, on markers of endothelial function. Healthy postmenopausal women (n = 22) completed a randomized, double-blind, placebo-controlled, crossover study. Women consumed daily a low-fat muffin, with or without a lignan complex, for 6 wk, separated by a 6-wk washout period. Flow-mediated, endothelium-dependent vasodilatation (FMD) and nitroglycerine-mediated, endothelium-independent vasodilatation were measured at the end of each intervention period. The sum of Plasma nitrite and nitrate (NOx), endothelin-1 (ET-1), and asymmetric dimethylarginine (ADMA) were measured at the beginning and end of each intervention period. FMD was 3.6 +/- 0.9% (mean +/- SEM) after the lignan complex intervention period compared with 3.9 +/- 0.7% after the placebo period (P = 0.72). Plasma concentrations of NOx, ET-1, and ADMA were not affected. We conclude that daily consumption for 6 wk of a low-fat muffin enriched with a lignan complex had no effect on endothelial function in healthy postmenopausal women.

4-Butyrolactone↗

PubMed2006

Process monitoring in intensive care with the use of cumulative expected minus observed mortality and risk-adjusted P charts.

INTRODUCTION: A health care system is a complex adaptive system. The effect of a single intervention, incorporated into a complex clinical environment, may be different from that expected. A national database such as the Intensive Care National Audit & Research Centre (ICNARC) Case Mix Programme in the UK represents a centralised monitoring, surveillance and reporting system for retrospective quality and comparative audit. This can be supplemented with real-time process monitoring at a local level for continuous process improvement, allowing early detection of the impact of both unplanned and deliberately imposed changes in the clinical environment. METHODS: Demographic and UK Acute Physiology and Chronic Health Evaluation II (APACHE II) data were prospectively collected on all patients admitted to a UK regional hospital between 1 January 2003 and 30 June 2004 in accordance with the ICNARC Case Mix Programme. We present a cumulative expected minus observed (E-O) plot and the risk-adjusted p chart as methods of continuous process monitoring. We describe the construction and interpretation of these charts and show how they can be used to detect planned or unplanned organisational process changes affecting mortality outcomes. RESULTS: Five hundred and eighty-nine adult patients were included. The overall death rate was 0.78 of predicted. Calibration showed excess survival in ranges above 30% risk of death. The E-O plot confirmed a survival above that predicted. Small transient variations were seen in the slope that could represent random effects, or real but transient changes in the quality of care. The risk-adjusted p chart showed several observations below the 2 SD control limits of the expected mortality rate. These plots provide rapid analysis of risk-adjusted performance suitable for local application and interpretation. The E-O chart provided rapid easily visible feedback of changes in risk-adjusted mortality, while the risk-adjusted p chart allowed statistical evaluation. CONCLUSION: Local analysis of risk-adjusted mortality data with an E-O plot and a risk-adjusted p chart is feasible and allows the rapid detection of changes in risk-adjusted outcome of intensive care patients. This complements the centralised national database, which is more archival and comparative in nature.

Critical Care↗

PubMed1990

Poverty and early childhood parenting: toward a framework for intervention.

The relationship between poverty and child rearing has been a persistent source of social concern in the United States. Drawing on available literature, this paper seeks to establish a conceptual approach to the interaction of these two complex variables. Appropriate interventions and strategies for their implementation are considered.

Child↗

PubMed2004

Simulation and critical care modeling.

PURPOSE OF REVIEW: Decisions made in critical care are often complicated, requiring an in-depth understanding of the relations between complex diseases, available interventions, and patients with a wide range of characteristics. Standard modeling techniques such as decision trees and statistical modeling have difficulty in capturing these interactions as the complexity of the problem increases. RECENT FINDINGS: Recent models in the literature suggest that simulation modeling techniques such as Markov modeling, Monte Carlo simulation, and discrete-event simulation are useful tools for analyzing complex systems in critical care. These simulation techniques are reviewed briefly, and examples from the literature are presented to demonstrate their usefulness in understanding real problems in critical care. SUMMARY: Simulation models provide useful tools for organizing and analyzing the interactions between therapies, tradeoffs, and outcomes.

Computer Simulation↗

PubMed2000

Therapeutic potential of ACE inhibitors for the treatment of hypertension in Type 2 diabetes.

Type 2 diabetes mellitus is associated with hypertension. If untreated, hypertension has a major impact on the clinical course of Type 2 diabetes and its vascular complications. In this review, we discuss rationale for the use of ACE inhibitors (ACEI) in hypertensive Type 2 diabetic patients and compare those theoretical assumptions with results of recent major clinical trials. Furthermore, possible directions for future clinical and experimental research are outlined. The RAS and its effector angiotensin II are important players in a number of cardiovascular and renal disorders. Recent evidence suggests that RAS and factors functionally linked to RAS are activated in Type 2 diabetes. Therefore, there is a theoretical basis for the use of ACEI in the treatment of hypertension in diabetic patients. Some recent studies reported superior outcome in patients treated with ACEI-based antihypertensive regimens compared with non-ACEI based treatments in reducing the risk of macrovascular disease (CAPPP, FACET, ABCD) or both micro- and macrovascular complications in Type 2 diabetes (HOPE). However, at least two of the large prospective studies discussed in this review (UKPDS 38, HOT), supported by results from previously published SHEP study, have recently suggested that the degree of reduction of blood pressure, rather than the choice of a particular class of antihypertensive agent, is associated with decreased risk of cardiovascular events. Studies focusing on renal end-points suggest that ACEI have a superior antiproteinuric effect than the other agents. However, whether ACEI are more nephroprotective, as assessed by the rate of decline in renal function, still remains to be elucidated. Despite promising results from recent trials, large numbers of patients progress despite ACEI treatment. Incomplete inhibition of the RAS may underlie this phenomenon. Treatment strategies that could enhance the degree of RAS inhibition represent one possible direction for clinical research in the near future. However, it is unlikely that the course of such a complex syndrome as Type 2 diabetes could be dramatically changed by just one class of antihypertensive agents. This goal is more likely to be achieved by multifactorial intervention, reflecting the complexity of metabolic syndrome. ACEI should be viewed as an important, but not the only, part of this complex approach.

Angiotensin-Converting Enzyme Inhibitors↗

PubMedDate not supplied

Interventions to improve diabetes self-management: utility and relevance for practice.

PURPOSE: The purpose of this study was to review publications of research on diabetes self-management interventions and assess whether the interventions are relevant for practice. METHODS: A content analysis was performed on research reports published between 1993 and 2004 of interventions designed to improve patients' diabetes self-management. Information was abstracted relevant to the intervention's generalizability to other settings and its compatibility and feasibility in practice. RESULTS: Publications included only limited information relevant to an intervention's generalizability across populations and settings. Many of the interventions tested were not designed to be compatible with the realities of current practice or to be delivered in the settings in which most diabetes care is provided. Many of the interventions were very complex, requiring multiple delivery modes and contacts, proactive scheduling, and coordination across disciplines. CONCLUSIONS: In view of the prevalence of diabetes, it is critical that effective self-management interventions be adopted and implemented. Interventions need to be designed so that their findings have greater relevance and utility for practice and can be generalized across practice settings.

Diabetes Mellitus↗

PubMed1995

Effect of cholesterol lowering on intravascular pools of TFPI and its anticoagulant potential in type II hyperlipoproteinemia.

Tissue factor pathway inhibitor (TFPI) inhibits the extrinsic coagulation system. A major pool of TFPI is associated with the vascular endothelium and can be mobilized into the circulation by heparin. In circulating blood, TFPI is mainly associated with LDL (80%), whereas 10% to 20% is carrier free. In this study, heparin administration caused a 2.2-fold and a 7.5-fold increase in TFPI activity and TFPI antigen, respectively, in 25 patients with phenotypes IIa and IIb hyperbetalipoproteinemia. Because the antigen determination of TFPI almost exclusively measures carrier-free TFPI, more than 90% of the heparin-induced increase in TFPI activity was caused by mobilization of carrier-free TFPI from the vascular endothelium. Therapeutic lowering of total cholesterol (a decrease of 31.1 +/- 11.6%, P < .001) by 40 mg/d lovastatin in 17 patients with hyperbetalipoproteinemia was accompanied by a parallel decrease in TFPI activity (of 27.7 +/- 24.2%, P < .001) because of a reduction in LDL-TFPI complexes. However, drug intervention did not affect carrier-free TFPI or the magnitude of the vascular pool of TFPI that could be mobilized into the circulation by heparin. Moreover, this reduction of LDL-TFPI complexes did not reduce the anticoagulant potency of TFPI in plasma or of the vascular endothelial pool. The results of this study may imply that the anticoagulant potency of TFPI is associated with its carrier-free form in plasma or on the endothelium and that downregulation of LDL affects neither the size nor the anticoagulant potency of the endothelial pool of TFPI.

Adult↗

PubMed2004

Analysis of response allocation in individuals with multiple forms of stereotyped behavior.

Three experiments were conducted to evaluate response allocation of stereotypy during free-operant and restricted-operant conditions. Five children with autism or related developmental disabilities participated in at least one and up to three of the experiments. In Experiment 1, the stereotypic response that emerged as most probable during a free-operant phase was restricted, and response allocation was again evaluated. The results for 3 participants showed that restricting the high-probability response was correlated with covarying reductions in a nontargeted stereotypy. In Experiment 2, the effect of environmental enrichment on response allocation was evaluated. One participant reallocated behavior to appropriate object manipulation, 1 participant showed no change in behavior, and a 3rd participant reallocated behavior to object manipulation only when the putative stimulus products of the object manipulation matched those of stereotypy. In Experiment 3, additional interventions were implemented to promote response reallocation. Results showed that both response restriction and reinforcement for object manipulation decreased stereotypy and increased object manipulation. Collectively, the results of these experiments point to a need for complex evaluations of interventions for stereotypy.

Child↗

PubMed2005

Evaluating the effect of policies and interventions to address inequalities in health: lessons from a Dutch programme.

OBJECTIVES: Many initiatives have been taken in European countries that are designed to reduce inequalities in health. However, the effects of only a very few of these initiatives have been assessed. The main aim of a Dutch research and development programme was to systematically investigate and evaluate interventions aimed at reducing inequalities in health. In this paper, we report on this investigation, and draw lessons from the methodology used to evaluate such interventions. APPROACH: The programme included 12 evaluation studies, focusing on the wider determinants of inequalities in health (n = 2), behavioural determinants (n = 4), working conditions (n = 3) and health care (n = 3). RESULTS: An experimental design was applied in two evaluation studies. The studies provided evidence of a positive effect. A quasi-experimental design appeared to be the only attainable option in seven studies. Five of these provided sufficient evidence for a positive effect, but two interventions appeared not to be successful. In three studies, no experimental or quasi-experimental design could be applied. CONCLUSIONS: The programme showed that it is possible to apply experimental or quasi-experimental studies to complex public health interventions. The Programme Committee steering the programme considered that the evidence generated by the experimental and quasi-experimental studies justified the implementation of the interventions on a wider scale, accompanied by further evaluation studies. Further development of the methodology of public health interventions is necessary. These include non-experimental designs such as international comparisons and time trend studies, especially in order to be able to evaluate broader policy measures.

Evidence-Based Medicine↗

PubMed2005

Incidence and management of "no-reflow" following percutaneous coronary interventions.

No-reflow is a complex condition associated with inadequate myocardial perfusion of the coronary artery in the absence of epicardial obstruction. It can occur in several settings, including percutaneous coronary intervention, especially in complex thrombotic lesions of native arteries and vein grafts and in primary angioplasty. The causes of no-reflow are not completely understood, and current treatments consist of intracoronary vasodilators, antithrombotic therapies, and mechanical devices (including aspiration thrombectomy catheters and embolic protection devices).

Adult↗

PubMed2003

The effects of an awareness-raising program for patients and primary care physicians on the early detection of gastro-oesophageal cancer.

OBJECTIVE: To test the efficacy of education by home letter, together with improved specialist/GP liaison, in promoting the detection of treatable gastro-oesophageal cancer in patients over 40. DESIGN: Prospective non-randomized trial with matched control group. PARTICIPANTS: 37,500 individuals over 40, registered with 12 general practices, were sent yearly letters for 3 consecutive years, advising them to consult a doctor with 4 specific symptoms. A matched control population of 60,500 received no intervention. MAIN OUTCOME MEASURES: Cancer cases were identified from cancer registry data, and the stage distribution and operability rates calculated from review of hospital case notes. RESULTS: Twenty of 59 cancer patients in the study group (34%) and 42 of 125 in the control group (34%) underwent resections; 24% (14/59) of study group and 18% (23/125) of control patients had "curable" disease (odds ratio [OR]= 1.51 [95%CI 0.71-3.23], X(2) = 1.164, P = 0.28). In year 1 of the study, 11 of 20 (55%) study group patients underwent resection compared to P 10 of 38 (26%) control group patients (P = 0.045, Fisher's exact test, OR = 3.4 [95% CI 1.09-0.7]). In year 1, 8 of 20 study patients (40%) had "curable" disease compared to 10.5% (4/38) control patients (P = 0.0128 Fisher's exact test, OR = 5.67 [95% CI 1.44 - 22.3]). There was no difference in survival between the groups overall or on comparing each year of study. CONCLUSION: This intervention caused a transient marked improvement in resection rate and curability, but the longer term impact on stage and resection rate was nonsignificant, and survival was not affected. Improving the detection of curable upper GI cancer is likely to require more complex and intensive interventions.

Adult↗

PubMed1982

A data-based approach to assessing clinical interventions in the setting of chronic disease.

Accurately assessing the effect of a clinical intervention is a complex task based on observing patients and their outcomes. Two strategies, the randomized trial and the observational data bank, represent different approaches toward detecting an outcome gradient across treatments. The observational data base is rooted on prospective data collected on an unselected group of patients with continuous surveillance of outcome events. As such, this approach captures a broad spectrum of patients within which prognostically important factors can be identified. In addition, the ongoing nature of the observational approach provides a means for capturing the dynamics of the disease process as well as the dynamics of the surrounding technology. These factors are particularly useful in the study of chronic illness where time frames of years to decades are encountered. In assessing treatment effects, both the randomized trial and the observational data base are subject to inferential errors due to multiple comparisons. In this paper, we describe some of the complexity associated with the study of chronic illness and demonstrate the multiple comparison problem. We have found multivariate models helpful in attenuating multiple comparison problems, but it still seems that independent confirmatory studies are required to establish confidence in a questionable intervention.

Analysis of Variance↗

PubMed2005

Complementary and alternative medicine whole systems research: beyond identification of inadequacies of the RCT.

Complementary and alternative medicine (CAM) often consists of whole systems of care (such as naturopathic medicine or traditional Chinese medicine (TCM)) that combine a wide range of modalities to provide individualised treatment. The complexity of these interventions and their potential synergistic effect requires innovative evaluative approaches. Model validity, which encompasses the need for research to adequately address the unique healing theory and therapeutic context of the intervention, is central to whole systems research (WSR). Classical randomised controlled trials (RCTs) are limited in their ability to address this need. Therefore, we propose a mixed methods approach that includes a range of relevant and holistic outcome measures. As the individual components of most whole systems are inseparable, complementary and synergistic, WSR must not focus only on the "active" ingredients of a system. An emerging WSR framework must be non-hierarchical, cyclical, flexible and adaptive, as knowledge creation is continuous, evolutionary and necessitates a continuous interplay between research methods and "phases" of knowledge. Finally, WSR must hold qualitative and quantitative research methods in equal esteem to realize their unique research contribution. Whole systems are complex and therefore no one method can adequately capture the meaning, process and outcomes of these interventions.

Complementary Therapies↗

PubMed2003