20 research outputs found
What are the main inefficiencies in trial conduct:a survey of UKCRC registered clinical trials units in the UK
No full textBACKGROUND: The UK Clinical Research Collaboration (UKCRC) registered Clinical Trials Units (CTUs) Network aims to support high-quality, efficient and sustainable clinical trials research in the UK. To better understand the challenges in efficient trial conduct, and to help prioritise tackling these challenges, we surveyed CTU staff. The aim was to identify important inefficiencies during two key stages of the trial conduct life cycle: (i) from grant award to first participant, (ii) from first participant to reporting of final results. METHODS: Respondents were asked to list their top three inefficiencies from grant award to recruitment of the first participant, and from recruitment of the first participant to publication of results. Free text space allowed respondents to explain why they thought these were important. The survey was constructed using SurveyMonkey and circulated to the 45 registered CTUs in May 2013. Respondents were asked to name their unit and job title, but were otherwise anonymous. Free-text responses were coded into broad categories. RESULTS: There were 43 respondents from 25 CTUs. The top inefficiency between grant award and recruitment of first participant was reported as obtaining research and development (R&D) approvals by 23 respondents (53%), contracts by 22 (51%), and other approvals by 13 (30%). The top inefficiency from recruitment of first participant to publication of results was failure to meet recruitment targets, reported by 19 (44%) respondents. A common comment was that this reflected overoptimistic or inaccurate estimates of recruitment at site. Data management, including case report form design and delays in resolving data queries with sites, was reported as an important inefficiency by 11 (26%) respondents, and preparation and submission for publication by 9 (21%). CONCLUSIONS: Recommendations for improving the efficiency of trial conduct within the CTUs network include: further reducing unnecessary bureaucracy in approvals and contracting; improving training for site staff; realistic recruitment targets and appropriate feasibility; developing training across the network; improving the working relationships between chief investigators and units; encouraging funders to release sufficient funding to allow prompt recruitment of trial staff; and encouraging more research into how to improve the efficiency and quality of trial conduct
UK Biobank: From concept to reality
No full textThe UK Biobank is a major UK collaborative research project to recruit and follow longitudinally the health of 500,000 volunteers aged between 40-69 years. It will provide important biological samples and environmental exposure data. As such, it will constitute a resource for many future investigations of the separate and combined effects of genetic, environmental and lifestyle factors on human morbidity, mortality and health. © 2005 Future Medicine Ltd
The influence of branded mobile applications on consumers’ perceptions of a brand : the importance of brand experience and engagement
No full textPurpose: This study aims to understand the real impact of branded mobile applications on consumer’s brand perception. Secondly, this study also aims to understand the importance and influence of the design of the application, and of the concepts of brand experience and engagement created by the application.
Methodology: The researcher used a mixed approach. First, he used secondary data by reviewing the literature linked to mobile applications, experience and engagement. The researcher then used primary data, obtained thanks to a mixed of qualitative and quantitative studies.
Findings: The experience and the “in-app” engagement created by the application are the key elements influencing consumer brand perceptions. Positive engaging experiences will greatly impact consumer behaviors resulting in more loyalty and word of mouth communication. Additionally, the design of the application, especially the content will have a huge impact on the brand experience created by the application and thus on the brand perceptions.
Limitations: The questionnaire was administered via Facebook and Twitter, which can lead to issues linked to the representativeness of the sample. In addition, as this is the first academic research conducted by the researcher, some limitations exists in relation to the lack of experience from the researcher.
Practical implications: Practitioners have to understand the concept of brand experience and engagement to implement a successful application and enhance consumer perceptions. They also have to understand the value of design and the role it plays on the two concepts.
Value of paper: This dissertation can help practitioners or academics seeking information related to mobile applications in a marketing context. It will also help to understand their impact on consumers brand perceptions and the role experience and engagement plays in shaping these. Author keywords: Branded mobile applications, brand experience, consumer brand engagement, brand perceptions, mobile marketin
Accuracy of patient self-report of stroke:A systematic review from the UK biobank stroke outcomes group
No full textObjective: We performed a systematic review of the accuracy of patient self-report of stroke to inform approaches to ascertaining and confirming stroke cases in large prospective studies. Methods: We sought studies comparing patient self-report against a reference standard for stroke. We extracted data on survey method(s), response rates, participant characteristics, the reference standard used, and the positive predictive value (PPV) of self-report. Where possible we also calculated sensitivity, specificity, negative predictive value (NPV), and stroke prevalence. Study-level risk of bias was assessed using the Quality Assessment of Diagnostic Studies tool (QUADAS-2). Results: From >1500 identified articles, we included 17 studies. Most asked patients to report a lifetime history of stroke but a few limited recall time to ≤5 years. Some included questions for transient ischaemic attack (TIA) or stroke synonyms. No study was free of risk of bias in the QUADAS-2 assessment, the most frequent causes of bias being incomplete reference standard data, absence of blinding of adjudicators to self-report status, and participant response rates (<80%). PPV of self-report ranged from 22-87% (17 studies), sensitivity from 36-98% (10 studies), specificity from 96-99.6% (10 studies), and NPV from 88.2-99.9% (10 studies). PPV increased with stroke prevalence as expected. Among six studies with available relevant data, if confirmed TIAs were considered to be true rather than false positive strokes, PPV of self-report was >75% in all but one study. It was not possible to assess the influence of recall time or of the question(s) asked on PPV or sensitivity. Conclusions: Characteristics of the study population strongly influence self-report accuracy. In population-based studies with low stroke prevalence, a large proportion of self-reported strokes may be false positives. Self-report is therefore unlikely to be helpful for identifying cases without subsequent confirmation, but may be useful for case ascertainment in combination with other data sources.</p
Sub-chronic feeding study of saxitoxin using mice
No full textRegulatory limits for shellfish toxins are often set using the results of acute toxicity testing (one-off dose) whereas in reality, people who eat shellfish often do so regularly. It is therefore important to determine the effect of shellfish toxins over an extended time period.
We investigated the effect of saxitoxin dihydrochloride (STX.2HCl) to mice in a 21-day feeding trial. To mimic human feeding behaviour mice were fed saxitoxin-laced food at twice daily ‘meal times’. Four treatment groups were used (5 female and 5 male per group) including a control group and three groups fed STX.2HCl at doses of 250, 490 and 715 µg/kg/day. Mice were individually caged with food consumption and bodyweight measured daily. In addition, motor control, blood pressure/heart rate and grip strength were measured weekly. Following the 21-day feeding period a blood sample was taken from each mouse for haematology/blood chemistry and the major organs were weighed. Histology sections of tissues were examined by a specialist veterinary pathologist. No adverse effects were observed.
Using the current EU regulatory limit of 800 µg STX.2HCl/kg shellfish flesh, the EFSA high portion size of 400 g and an adult bodyweight of 70 kg, the amount of saxitoxin that can be safely ingested is 4.6 µg/kg bodyweight. Taking into account the 100-fold safety factor used to extrapolate from animal data to human, mice in this experiment were fed up to 1.5 times this dietary intake for 21 consecutive days without adverse effects. The current saxitoxin regulatory limit therefore seems adequate
Sub-Acute Feeding Study of Saxitoxin to Mice Confirms the Effectiveness of Current Regulatory Limits for Paralytic Shellfish Toxins
No full textRegulatory limits for shellfish toxins are required to protect human health. Often these limits are set using only acute toxicity data, which is significant, as in some communities, shellfish makes up a large proportion of their daily diet and can be contaminated with paralytic shellfish toxins (PSTs) for several months. In the current study, feeding protocols were developed to mimic human feeding behaviour and diets containing three dose rates of saxitoxin dihydrochloride (STX.2HCl) were fed to mice for 21 days. This yielded STX.2HCl dose rates of up to 730 µg/kg bw/day with no effects on food consumption, growth, blood pressure, heart rate, motor coordination, grip strength, blood chemistry, haematology, organ weights or tissue histology. Using the 100-fold safety factor to extrapolate from animals to humans yields a dose rate of 7.3 µg/kg bw/day, which is well above the current acute reference dose (ARfD) of 0.5 µg STX.2HCl eq/kg bw proposed by the European Food Safety Authority. Furthermore, to reach the dose rate of 7.3 µg/kg bw, a 60 or 70 kg human would have to consume 540 or 630 g of shellfish contaminated with PSTs at the current regulatory limit (800 µg/kg shellfish flesh), respectively. The current regulatory limit for PSTs therefore seems appropriate
A Sub-Acute Dosing Study of Saxitoxin and Tetrodotoxin Mixtures in Mice Suggests That the Current Paralytic Shellfish Toxin Regulatory Limit Is Fit for Purpose
No full textParalytic shellfish poisoning is a worldwide problem induced by shellfish contaminated with paralytic shellfish toxins. To protect human health, a regulatory limit for these toxins in shellfish flesh has been adopted by many countries. In a recent study, mice were dosed with saxitoxin and tetrodotoxin mixtures daily for 28 days showing toxicity at low concentrations, which appeared to be at odds with other work. To further investigate this reported toxicity, we dosed groups of mice with saxitoxin and tetrodotoxin mixtures daily for 21 days. In contrast to the previous study, no effects on mouse bodyweight, food consumption, heart rate, blood pressure, grip strength, blood chemistry or hematology were observed. Furthermore, no histological findings were associated with dosing in this trial. The dose rates in this study were 2.6, 3.8 and 4.9 times greater, respectively, than the highest dose of the previous study. As rapid mortality in three out of five mice was observed in the previous study, the deaths are likely to be due to the methodology used rather than the shellfish toxins. To convert animal data to that used in a human risk assessment, a 100-fold safety factor is required. After applying this safety factor, the dose rates used in the current study were 3.5, 5.0 and 6.5 times greater, respectively, than the acute reference dose for each toxin type set by the European Union. Furthermore, it has previously been proposed that tetrodotoxin be included in the paralytic shellfish poisoning suite of toxins. If this were done, the highest dose rate used in this study would be 13 times the acute reference dose. This study suggests that the previous 28-day trial was flawed and that the current paralytic shellfish toxin regulatory limit is fit for purpose. An additional study, feeding mice a diet laced with the test compounds at higher concentrations than those of the current experiment, would be required to comment on whether the current paralytic shellfish toxin regulatory limit should be modified
A sub-acute dosing study of saxitoxin and tetrodotoxin mixtures in mice suggests that the current paralytic shellfish toxin regulatory limit is fit for purpose
No full textParalytic shellfish poisoning is a worldwide problem induced by shellfish contaminated with paralytic shellfish toxins. To protect human health, a regulatory limit for these toxins in shellfish flesh has been adopted by many countries. In a recent study, mice were dosed with saxitoxin and tetrodotoxin mixtures daily for 28 days showing toxicity at low concentrations, which appeared to be at odds with other work. To further investigate this reported toxicity, we dosed groups of mice with saxitoxin and tetrodotoxin mixtures daily for 21 days. In contrast to the previous study, no effects on mouse bodyweight, food consumption, heart rate, blood pressure, grip strength, blood chemistry or hematology were observed. Furthermore, no histological findings were associated with dosing in this trial. The dose rates in this study were 2.6, 3.8 and 4.9 times greater, respectively, than the highest dose of the previous study. As rapid mortality in three out of five mice was observed in the previous study, the deaths are likely to be due to the methodology used rather than the shellfish toxins. To convert animal data to that used in a human risk assessment, a 100-fold safety factor is required. After applying this safety factor, the dose rates used in the current study were 3.5, 5.0 and 6.5 times greater, respectively, than the acute reference dose for each toxin type set by the European Union. Furthermore, it has previously been proposed that tetrodotoxin be included in the paralytic shellfish poisoning suite of toxins. If this were done, the highest dose rate used in this study would be 13 times the acute reference dose. This study suggests that the previous 28-day trial was flawed and that the current paralytic shellfish toxin regulatory limit is fit for purpose. An additional study, feeding mice a diet laced with the test compounds at higher concentrations than those of the current experiment, would be required to comment on whether the current paralytic shellfish toxin regulatory limit should be modified.</p
Sub-acute feeding study of saxitoxin to mice confirms the effectiveness of current regulatory limits for paralytic shellfish toxins
No full textRegulatory limits for shellfish toxins are required to protect human health. Often these limits are set using only acute toxicity data, which is significant, as in some communities, shellfish makes up a large proportion of their daily diet and can be contaminated with paralytic shellfish toxins (PSTs) for several months. In the current study, feeding protocols were developed to mimic human feeding behaviour and diets containing three dose rates of saxitoxin dihydrochloride (STX.2HCl) were fed to mice for 21 days. This yielded STX.2HCl dose rates of up to 730 µg/kg bw/day with no effects on food consumption, growth, blood pressure, heart rate, motor coordination, grip strength, blood chemistry, haematology, organ weights or tissue histology. Using the 100-fold safety factor to extrapolate from animals to humans yields a dose rate of 7.3 µg/kg bw/day, which is well above the current acute reference dose (ARfD) of 0.5 µg STX.2HCl eq/kg bw proposed by the European Food Safety Authority. Furthermore, to reach the dose rate of 7.3 µg/kg bw, a 60 or 70 kg human would have to consume 540 or 630 g of shellfish contaminated with PSTs at the current regulatory limit (800 µg/kg shellfish flesh), respectively. The current regulatory limit for PSTs therefore seems appropriate
