Decision Tree Analysis as a Supplementary Tool to Enhance Histomorphological Differentiation when Distinguishing Human from Non-human Cranial Bone in both Burnt and Unburnt States: A feasibility study

This feasibility study was undertaken to describe and record the histological characteristics of burnt and unburnt cranial bone fragments from human and non-human bones. Reference series of fully mineralised, transverse sections of cranial bone, from all variables and specimen states were prepared by manual cutting and semi-automated grinding and polishing methods. A photomicrograph catalogue reflecting differences in burnt and unburnt bone from human and non-humans was recorded and qualitative analysis was performed using an established classification system based on primary bone characteristics. The histomorphology associated with human and non-human samples was, for the main part, preserved following burning at high temperature. Clearly, fibro-lamellar complex tissue subtypes, such as plexiform or laminar primary bone, were only present in non-human bones. A decision tree analysis based on histological features provided a definitive identification key for distinguishing human from non-human bone, with an accuracy of 100%. The decision tree for samples where burning was unknown was 96% accurate, and multi-step classification to taxon was possible with 100% accuracy. The results of this feasibility study, strongly suggest that histology remains a viable alternative technique if fragments of cranial bone require forensic examination in both burnt and unburnt states. The decision tree analysis may provide an additional, but vital tool to enhance data interpretation. Further studies are needed to assess variation in histomorphology taking into account other cranial bones, ontogeny, species and burning conditions

DNA transport by a micromachined Brownian ratchet device

We have micromachined a silicon-chip device that transports DNA with a Brownian ratchet that rectifies the Brownian motion of microscopic particles. Transport properties for a DNA 50mer agree with theoretical predictions, and the DNA diffusion constant agrees with previous experiments. This type of micromachine could provide a generic pump or separation component for DNA or other charged species as part of a microscale lab-on-a-chip. A device with reduced feature size could produce a size-based separation of DNA molecules, with applications including the detection of single nucleotide polymorphisms.Comment: Latex: 8 pages, 4 figure

Changes in undergraduate student alcohol consumption as they progress through university

BACKGROUND: Unhealthy alcohol use amongst university students is a major public health concern. Although previous studies suggest a raised level of consumption amongst the UK student population there is little consistent information available about the pattern of alcohol consumption as they progress through university. The aim of the current research was to describe drinking patterns of UK full-time undergraduate students as they progress through their degree course. METHOD: Data were collected over three years from 5895 undergraduate students who began their studies in either 2000 or 2001. Longitudinal data (i.e. Years 1–3) were available from 225 students. The remaining 5670 students all responded to at least one of the three surveys (Year 1 n = 2843; Year 2 n = 2219; Year 3 n = 1805). Results: Students reported consuming significantly more units of alcohol per week at Year 1 than at Years 2 or 3 of their degree. Male students reported a higher consumption of units of alcohol than their female peers. When alcohol intake was classified using the Royal College of Physicians guidelines [1] there was no difference between male and females students in terms of the percentage exceeding recommended limits. Compared to those who were low level consumers students who reported drinking above low levels at Year 1 had at least 10 times the odds of continuing to consume above low levels at year 3. Students who reported higher levels of drinking were more likely to report that alcohol had a negative impact on their studies, finances and physical health. Consistent with the reduction in units over time students reported lower levels of negative impact during Year 3 when compared to Year 1. CONCLUSION: The current findings suggest that student alcohol consumption declines over their undergraduate studies; however weekly levels of consumption at Year 3 remain high for a substantial number of students. The persistence of high levels of consumption in a large population of students suggests the need for effective preventative and treatment interventions for all year groups

Evaluating the impact of an intervention to increase uptake of modern contraceptives among adolescent girls (15-19 years) in Nigeria, Ethiopia and Tanzania: the Adolescents 360 quasi-experimental study protocol.

INTRODUCTION: Nigeria, Ethiopia and Tanzania have some of the highest teenage pregnancy rates and lowest rates of modern contraceptive use among adolescents. The transdisciplinary Adolescents 360 (A360) initiative being rolled out across these three countries uses human-centred design to create context-specific multicomponent interventions with the aim of increasing voluntary modern contraceptive use among girls aged 15-19 years. METHODS: The primary objective of the outcome evaluation is to assess the impact of A360 on the modern contraceptive prevalence rate (mCPR) among sexually active girls aged 15-19 years. A360 targets different subpopulations of adolescent girls in the three countries. In Northern Nigeria and Ethiopia, the study population is married girls aged 15-19 years. In Southern Nigeria, the study population is unmarried girls aged 15-19 years. In Tanzania, both married and unmarried girls aged 15-19 years will be included in the study. In all settings, we will use a prepopulation and postpopulation-based cross-sectional survey design. In Nigeria, the study design will also include a comparison group. A one-stage sampling design will be used in Nigeria and Ethiopia. A two-stage sampling design will be used in Tanzania. Questionnaires will be administered face-to-face by female interviewers aged between 18 and 26 years. Study outcomes will be assessed before the start of A360 implementation in late 2017 and approximately 24 months after implementation in late 2019. ETHICS AND DISSEMINATION: Findings of this study will be widely disseminated through workshops, conference presentations, reports, briefings, factsheets and academic publications

Estimating a preference-based single index measuring the quality of life impact of self-management for diabetes

Objective. Self-management is becoming increasingly important in diabetes but is neglected in conventional preference-based measures. The objective of this paper was to generate health state utility values for a novel classification system measuring the quality-of-life impact of self-management for diabetes, which can be used to generate quality-adjusted life years (QALYs). Methods. A large online survey was conducted using a discrete choice experiment (DCE), with duration as an additional attribute, on members of the UK general population (n = 1,493) to elicit values for health (social limitations, mood, vitality, hypoglycaemia) and non-health (stress, hassle, control, support) aspects of self-management in diabetes. The data were modelled using a conditional fixed-effects logit model and utility estimates were anchored on the one to zero (full health to dead) scale. Results. The model produced significant and consistent coefficients, with one logical inconsistency and 3 insignificant coefficients for the milder levels of some attributes. The anchored utilities ranged from 1 for the best state to −0.029 for the worst state (meaning worse than dead) defined by the classification system. Conclusion. The results presented here can potentially be used to generate utility values capturing the day to day impact of interventions in diabetes on both health and self-management. These utility values can potentially be used to generate QALYs for economic models of the cost-effectiveness of interventions in diabetes

Comparing the measurement equivalence of EQ-5D-5L across different modes of administration

Background: Interest in collecting Patient Reported Outcomes using electronic methods such as mobile phones has increased in recent years. However there is debate about the level of measurement equivalence between the traditional paper and newer electronic modes. Information about the acceptability of the electronic versions to respondents is also required. The aim of this study is to compare the equivalence of delivering a widely used generic measure of health status (EQ-5D-5L) across two administration modes (paper and mobile phone). Methods: Respondents from a research cohort of people in South Yorkshire were identified, and randomly allocated to one of two administration modes (paper vs. mobile phone) based on stratifications for age and gender (and across a range of self-reported health conditions). A parallel group design was used where each respondent only completed EQ-5D-5L using one of the modes. In total, 70 respondents completed the measure in the mobile phone arm, and 66 completed the standard paper version. Follow up usability questions were also included to assess the acceptability of the mobile version of EQ-5D-5L. Measurement equivalence was compared at the dimension, utility score and visual analogue scale level using chi square analysis and ANOVA, and by comparing mean differences to an estimated minimally important difference value. Results: Response rates were higher in the mobile arm. The mean EQ-5D-5L utility and VAS scores, and the frequency of respondents endorsing individual EQ-5D-5L dimension response levels did not significantly differ across the administration modes. The majority of the mobile arm agreed that the mobile version of EQ-5D-5L was easy to complete, and that the phone was easy to use, and that they would complete mobile health measures again. Conclusions: Completing health status measures such as EQ-5D using mobile phones produces equivalent results to more traditional methods, but with added benefits (for example lessening the burden of data entry). Respondents are positive towards completing questionnaires using these methods. The results provide evidence that electronic measures are valid for use to collect data in a range of settings including clinical trials, routine care, and in health diary settings

An EQ-5D-5L Value Set for Ghana Using an Adapted EuroQol Valuation Technology Protocol.

OBJECTIVES: Ghana's economic evaluation reference case recommends quality-adjusted life-years as an outcome measure for the conduct of cost-utility analysis. There is no Ghanaian value set available to be used in estimating quality-adjusted life-years. This study aimed to develop a value set for Ghana using the EQ-5D-5L instrument. METHODS: Face-to-face preference data were collected from 300 adults across 3 regions of Ghana using the adapted version of the EuroQol valuation technology (EQ-VT) standardized valuation protocol; with composite time-trade-off (cTTO) and discrete-choice experiments (DCEs) elicitation techniques. The cTTO and DCE data were modeled individually or together to provide complementary results on respondents' utility preferences. Models explored were generalized least squares, Tobit, heteroskedastic, logit, and hybrid. The best-fitting model for the value set was selected based on its logical consistency, accounting for left-censored and heteroscedasticity data, and the statistical significance of parameters. RESULTS: The 300 interviews provided 4500 cTTO responses and 4200 DCE responses. The preferred model chosen for the Ghana value set was the Hybrid Tobit random effect heteroscedastic-constrained model. The predicted value for the worst attainable health state (55555) was -0.493 and the best health state (11112) was 0.969. The largest decrement was registered for level 5 mobility (0.369) followed by pain/discomfort (0.312), self-care (0.273), anxiety/depression (0.271), and usual activities (0.268). CONCLUSIONS: This is the first Ghanaian EQ-5D-5L value set based on social preference derived from a nationally representative sample. The value set will play a key role in the use of economic evaluation studies to inform priority setting in Ghana where different health technologies can be compared

How robust are value judgements of health inequality aversion? Testing for framing and cognitive effects

Background: Empirical studies have found that members of the public are inequality averse and value health gains for disadvantaged groups with poor health many times more highly than gains for better off groups. However, these studies typically use abstract scenarios that involve unrealistically large reductions in health inequality, and face-to-face survey administration. It is not known how robust these findings are to more realistic scenarios or anonymous online survey administration. Methods: This study aimed to test the robustness of questionnaire estimates of inequality aversion by comparing the following: (1) small versus unrealistically large health inequality reductions; (2) population-level versus individual-level descriptions of health inequality reductions; (3) concrete versus abstract intervention scenarios; and (4) online versus face to face mode of administration. Fifty-two members of the public participated in face-to-face discussion groups, while 83 members of the public completed an online survey. Participants were given a questionnaire instrument with different scenario descriptions for eliciting aversion to social inequality in health. Results: The median respondent was inequality averse under all scenarios. Scenarios involving small rather than unrealistically large health gains made little difference in terms of inequality aversion, as did population-level rather than individual-level scenarios. However, the proportion expressing extreme inequality aversion fell 19 percentage points when considering a specific health intervention scenario rather than an abstract scenario, and was 11-21 percentage points lower among online public respondents compared to the discussion group. Conclusions: Our study suggests that both concrete scenarios and online administration reduce the proportion expressing extreme inequality aversion but still yield median responses implying substantial health inequality aversion

Australian utility weights for the EORTC QLU-C10D, a multi-attribute utility instrument derived from the cancer-specific quality of life questionnaire, EORTC QLQ-C30

Background: The EORTC QLU-C10D is a new multi-attribute utility instrument derived from the widely-used cancer-specific quality of life questionnaire, EORTC QLQ-C30. The QLU-C10D contains ten dimensions (Physical, Role, Social and Emotional Functioning; Pain, Fatigue, Sleep, Appetite, Nausea, Bowel Problems), each with 4 levels. To be used in cost-utility analysis, country-specific valuation sets are required. Objective: To provide Australian utility weights for the QLU-C10D. Methods: An Australian online panel was quota sampled to ensure population representativeness by sex and age (≥18y). Participants completed a discrete choice experiment (DCE) consisting of 16 choice-pairs. Each pair comprised two QLU-C10D health states plus life expectancy. Data were analysed using conditional logistic regression, parameterised to fit the quality-adjusted life-year framework. Utility weights were calculated as the ratio of each QOL dimension-level coefficient to the coefficient on life expectancy. Results: 1979 panel members opted-in, 1904 (96%) completed at least one choice-pair, and 1846 (93%) completed all 16 choice-pairs. Dimension weights were generally monotonic: poorer levels within each dimension were generally associated with greater utility decrements. The dimensions that impacted most on choice were, in order, Physical Functioning, Pain, Role Functioning and Emotional Functioning. Oncology-relevant dimensions with moderate impact were Nausea and Bowel Problems. Fatigue, Trouble Sleeping and Appetite had relatively small impact. The value of the worst health state was -0.096, somewhat worse than death. Conclusions: This study provides the first country-specific value set for the QLU-C10D, which can facilitate cost-utility analyses when applied to data collected with the EORTC QLQ-C30, prospectively and retrospectively