Criticality Analysis of Activity Networks under Interval Uncertainty

Dedicated to the memory of Professor Stefan Chanas - The extended abstract version of this paper has appeared in Proceedings of 11th International Conference on Principles and Practice of Constraint Programming (CP2005) ("Interval Analysis in Scheduling", Fortin et al. 2005)International audienceThis paper reconsiders the Project Evaluation and Review Technique (PERT) scheduling problem when information about task duration is incomplete. We model uncertainty on task durations by intervals. With this problem formulation, our goal is to assert possible and necessary criticality of the different tasks and to compute their possible earliest starting dates, latest starting dates, and floats. This paper combines various results and provides a complete solution to the problem. We present the complexity results of all considered subproblems and efficient algorithms to solve them

SMART: Self-Management of Anticoagulation, a Randomised Trial [ISRCTN19313375]

Background: Oral anticoagulation monitoring has traditionally taken place in secondary care because of the need for a laboratory blood test, the international normalised ratio (INR). The development of reliable near patient testing (NPT) systems for INR estimation has facilitated devolution of testing to primary care. Patient self-management is a logical progression from the primary care model. This study will be the first to randomise non-selected patients in primary care, to either self-management or standard care. Method: The study was a multi-centred randomised controlled trial with patients from 49 general practices recruited. Those suitable for inclusion were aged 18 or over, with a long term indication for oral anticoagulation, who had taken warfarin for at least six months. Patients randomised to the intervention arm attended at least two training sessions which were practice-based, 1 week apart. Each patient was assessed on their capability to undertake self management. If considered capable, they were given a near patient INR testing monitor, test strips and quality control material for home testing. Patients managed their own anticoagulation for a period of 12 months and performed their INR test every 2 weeks. Control patients continued with their pre-study care either attending hospital or practice based anticoagulant clinics. Discussion: The methodology used in this trial will overcome concerns from previous trials of selection bias and relevance to the UK health service. The study will give a clearer understanding of the benefits of self-management in terms of clinical and cost effectiveness and patient preference

Awareness and attitudes towards external auditory canal exostosis and its preventability in surfers in the UK:cross-sectional study

AbstractObjectives:To determine the proportion of UK surfers aware of external auditory canal exostosis, to identify surfer characteristics associated with knowledge of the condition and to explore attitudes to earplug use.Method:An online, cross-sectional survey of UK-based surfers.Results:Of 375 surfers, 86.1 per cent (n = 323; 95 per cent confidence interval = 82.3–89.3) reported awareness of external auditory canal exostosis. Further investigation revealed that, despite their awareness of the condition, 23.4 per cent of these surfers (88 out of 323; 95 per cent confidence interval = 19.5–28.0) had little or no knowledge about external auditory canal exostosis. Predictors of knowledge included: distance from nearest surfing beach (p = 0.001), surfing standard (ability) (p = 0.008), earplug use (p = 0.024) and positive external auditory canal exostosis diagnosis (p = 0.009).Conclusion:The findings suggest that a significant minority of UK surfers have no knowledge about this condition. Knowledge of external auditory canal exostosis was significantly associated with earplug use when surfing. Efforts to improve surfers’ knowledge are required to enable surfers to better protect themselves, which could reduce the incidence of external auditory canal exostosis.</jats:sec

A randomised controlled trial of extended anticoagulation treatment versus standard treatment for the prevention of recurrent venous thromboembolism (VTE) and post-thrombotic syndrome in patients being treated for a first episode of unprovoked VTE (the ExACT study)

Venous thromboembolism (VTE) is prevalent and impactful, with a risk of death, morbidity and recurrence. Post‐thrombotic syndrome (PTS) is a common consequence and associated with impaired quality of life (QoL). The ExACT study was a non‐blinded, prospective, multicentred randomised controlled trial comparing extended versus limited duration anticoagulation following a first unprovoked VTE (proximal deep vein thrombosis or pulmonary embolism). Adults were eligible if they had completed ≥3 months anticoagulation (remaining anticoagulated). The primary outcome was time to first recurrent VTE from randomisation. The secondary outcomes included PTS severity, bleeding, QoL and D‐dimers. Two‐hundred and eighty‐one patients were recruited, randomised and followed up for 24 months (mean age 63, male:female 2:1). There was a significant reduction in recurrent VTE for patients receiving extended anticoagulation [2·75 vs. 13·54 events/100 patient years, adjusted hazard ratio (aHR) 0·20 (95% confidence interval (CI): 0·09 to 0·46, P < 0·001)] with a non‐significant increase in major bleeding [3·54 vs. 1·18 events/100 patient years, aHR 2·99 (95% CI: 0·81–11·05, P = 0·10)]. Outcomes of PTS and QoL were no different between groups. D‐dimer results (on anticoagulation) did not predict VTE recurrence. In conclusion, extended anticoagulation reduced VTE recurrence but did not reduce PTS or improve QoL and was associated with a non‐significant increase in bleeding. Results also suggest very limited clinical utility of D‐dimer testing on anticoagulated patients

Young people and greenhouse gas emissions at music festivals

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link

Subclinical thyroid dysfunction symptoms in older adults : cross-sectional study in UK primary care

Background Subclinical thyroid dysfunction — abnormal serum thyrotrophin (thyroid-stimulating hormone; TSH) concentrations with normal free thyroxine (FT4) is common in older people. It remains unclear whether individuals with subclinical serum status experience an increased symptom profile. Aim To compare the prevalence of those symptoms typically associated with overt thyroid dysfunction in older individuals with a subclinical and euthyroid serum profile. Design and setting Cross-sectional study, nested within the Birmingham Elderly Thyroid Study (BETS); from 19 UK general practices. Method Adults living in a community setting (aged ≥65 years), without overt thyroid dysfunction or associated treatment, self-reported the presence or absence of 18 symptoms (while serum result naïve). Serum concentrations of TSH and FT4 were measured to establish thyroid status. Results A total of 2870 individuals were screened: 2703 (94%) were categorised as euthyroid (normal), 29 (1%) subclinically hyperthyroid, and 138 (5%) subclinically hypothyroid. Symptoms were common in all groups. No significant differences in the prevalence of individual symptoms were observed between the euthyroid and subclinically hypothyroid groups nor in comparison with the subclinically hyperthyroid group. Multivariate logistic regression analysis failed to reveal an association between individual or multiple symptoms and subclinical status. Conclusion Findings suggest that subclinical thyroid dysfunction does not confer a symptom burden in older individuals and support adherence to guidelines in the non-treatment of subclinical thyroid dysfunction. GPs may use the findings to reassure older people presenting with symptoms that subclinical thyroid dysfunction is an unlikely explanation. The presence of persistently abnormal TSH concentrations may be linked to long-term risks of cardiovascular disease, especially atrial fibrillation, but whether this should prompt treatment and whether such treatment alters vascular outcomes is unknown

Primary care REFerral for EchocaRdiogram (REFER) in heart failure: a diagnostic accuracy study.

BACKGROUND: Symptoms of breathlessness, fatigue, and ankle swelling are common in general practice but deciding which patients are likely to have heart failure is challenging. AIM: To evaluate the performance of a clinical decision rule (CDR), with or without N-Terminal pro-B type natriuretic peptide (NT-proBNP) assay, for identifying heart failure. DESIGN AND SETTING: Prospective, observational, diagnostic validation study of patients aged >55 years, presenting with shortness of breath, lethargy, or ankle oedema, from 28 general practices in England. METHOD: The outcome was test performance of the CDR and natriuretic peptide test in determining a diagnosis of heart failure. The reference standard was an expert consensus panel of three cardiologists. RESULTS: Three hundred and four participants were recruited, with 104 (34.2%; 95% confidence interval [CI] = 28.9 to 39.8) having a confirmed diagnosis of heart failure. The CDR+NT-proBNP had a sensitivity of 90.4% (95% CI = 83.0 to 95.3) and specificity 45.5% (95% CI = 38.5 to 52.7). NT-proBNP level alone with a cut-off <400 pg/ml had sensitivity 76.9% (95% CI = 67.6 to 84.6) and specificity 91.5% (95% CI = 86.7 to 95.0). At the lower cut-off of NT-proBNP <125 pg/ml, sensitivity was 94.2% (95% CI = 87.9 to 97.9) and specificity 49.0% (95% CI = 41.9 to 56.1). CONCLUSION: At the low threshold of NT-proBNP <125 pg/ml, natriuretic peptide testing alone was better than a validated CDR+NT-proBNP in determining which patients presenting with symptoms went on to have a diagnosis of heart failure. The higher NT-proBNP threshold of 400 pg/ml may mean more than one in five patients with heart failure are not appropriately referred. Guideline natriuretic peptide thresholds may need to be revised