A comparison of direct and indirect methods for the estimation of health utilities from clinical outcomes

Background: Analysts often need to estimate health state utility values as a function of other outcome measures. Utility values like EQ-5D have several unusual characteristics that make standard statistical methods inappropriate. We have developed a bespoke approach based on mixture models to directly estimate EQ-5D. An indirect method, “response mapping”, first estimates the level on each of the five dimensions of the EQ-5D descriptive system and then calculates the expected tariff score. These methods have never previously been compared. Methods: We use a large observational database of patients diagnosed with Rheumatoid Arthritis (n=100,398 observations). Direct estimation of UK EQ-5D scores as a function of Health Assessment Questionnaire (HAQ), pain and age was performed using a limited dependent variable mixture model. Indirect modelling was undertaken using a set of generalized ordered probit models with expected tariff scores calculated mathematically. Linear regression was reported for comparison purposes. Results: The linear model fits poorly, particularly at the extremes of the distribution. Both the bespoke mixture model and the generalized ordered probit approach offer improvements in fit over the entire range of EQ-5D. Mean average error is 10% and 5% lower compared to the linear model respectively. Root mean squared error is 3% and 2% lower. The mixture model demonstrates superior performance to the indirect method across almost the entire range of pain and HAQ. Limitations: There is limited data from patients in the most extreme HAQ health states. Conclusions: Modelling of EQ-5D from clinical measures is best performed directly using the bespoke mixture model. This substantially outperforms the indirect method in this example. Linear models are inappropriate, suffer from systematic bias and generate values outside the feasible range

Paternal effects correlate with female reproductive stimulation in the polyandrous ladybird Cheilomenes sexmaculata

Citation: Mirhosseini, M., Michaud, J., Jalali, M., & Ziaaddini, M. (2014). Paternal effects correlate with female reproductive stimulation in the polyandrous ladybird Cheilomenes sexmaculata. Bulletin of Entomological Research, 104(4), 480-485. https://doi.org/10.1017/S0007485314000194Components of male seminal fluids are known to stimulate fecundity and fertility in females of numerous insect species and paternal effects on offspring phenotype are also known, but no studies have yet demonstrated links between male effects on female reproduction and those on progeny phenotype. In separate laboratory experiments employing 10-day-old virgin females of Cheilomenes sexmaculata (F.), we varied male age and mating history to manipulate levels of male allomones and found that the magnitude of paternal effects on progeny phenotype was correlated with stimulation of female reproduction. Older virgin males remained in copula longer than younger ones, induced higher levels of female fecundity, and sired progeny that developed faster to yield heavier adults. When male age was held constant (13 days), egg fertility declined as a function of previous male copulations, progeny developmental times increased, and the adult weight of daughters declined. These results suggest that male epigenetic effects on progeny phenotype act in concert with female reproductive stimulation; both categories of effects increased as a consequence of male celibacy (factor accumulation), and diminished as a function of previous matings (factor depletion). Male factors that influence female reproduction are implicated in sexual conflict and parental effects may extend this conflict to offspring phenotype. Whereas mothers control the timing of oviposition events and can use maternal effects to tailor progeny phenotypes to prevailing or anticipated conditions, fathers cannot. Since females remate and dilute paternity in polyandrous systems, paternal fitness will be increased by linking paternal effects to female fecundity stimulation, so that more benefits accrue to the male's own progeny

Sport activity in adolescence: associations with health perceptions and experimental behaviours

Despite the relevance of this research topic from a public health perspective, there is currently a lack of objective data on European adolescents' sport activity, notably the associations between their sport habits and their health attitudes and behaviours, which may have important consequences both in terms of somatic (cardiovascular) health and mental health. The objective of the present study was to determine the direction and strength of the associations between the frequency of sport and health variables; in particular, perceptions of health, self image, substance use and experimental behaviours. Data were collected as part of the 1993 Swiss Multicentric Adolescent Survey on Health. In this survey, anonymous self-administered questionnaires were distributed to a national representative sample of 10 000 in-school adolescents (15-20 years of age). Univariate analyses explored the relationships between the level of sport activity and health variables; then logistic regression analyses examined the strength of these relationships. According to the results, half of the sample do sports more than twice a week, boys more often as part of a sports club. Differences between non-athletic and athletic adolescents describe the latter as having less somatic complaints, more confidence in their future health, a better body image, a lesser tendency to attempt suicide, a higher frequency of use of the car seat belt, and a lower use of tobacco, wine and marijuana. Links between the frequency of sport activity and the locus of control related to health, general satisfaction with life or sexual behaviours are less strong. It must be noticed that the cross-sectional data collection precludes the establishment of a causal relationship between exercise and health behaviours. However, the existing links underline the coexistence of positive health characteristics and sport activity, suggesting that an incitement to get involved in physical activity may be a necessary component of a comprehensive prevention approach among adolescent

Bayesian Non-Exhaustive Classification A Case Study: Online Name Disambiguation using Temporal Record Streams

The name entity disambiguation task aims to partition the records of multiple real-life persons so that each partition contains records pertaining to a unique person. Most of the existing solutions for this task operate in a batch mode, where all records to be disambiguated are initially available to the algorithm. However, more realistic settings require that the name disambiguation task be performed in an online fashion, in addition to, being able to identify records of new ambiguous entities having no preexisting records. In this work, we propose a Bayesian non-exhaustive classification framework for solving online name disambiguation task. Our proposed method uses a Dirichlet process prior with a Normal * Normal * Inverse Wishart data model which enables identification of new ambiguous entities who have no records in the training data. For online classification, we use one sweep Gibbs sampler which is very efficient and effective. As a case study we consider bibliographic data in a temporal stream format and disambiguate authors by partitioning their papers into homogeneous groups. Our experimental results demonstrate that the proposed method is better than existing methods for performing online name disambiguation task.Comment: to appear in CIKM 201

Emission Lines in the Spectrum of the 3He Star 3 Cen A

Emission in the 4d - 4f transitions of MnII (multiplet 13, 6122-6132 Ang), in the 4f - 6g transitions of PII, and in 6149.5 Ang of HgII has been detected in the spectrum of the helium weak star 3 Centauri A (B5 III-IVp). Weaker emission from the same MnII multiplet is also seen in the hot, mild HgMn star 46 Aquila (B9 III).It is suggested that the emission is of photospheric origin and may be evidence for the stratification of manganese, phosphorus and mercury in the photosphere of 3 CenA, and of manganese in 46Aql.Comment: 16 pages, 3 figure

Gravitational settling in pulsating subdwarf B stars and their progenitors

Diffusion of atoms can be important during quiescent phases of stellar evolution. Particularly in the very thin inert envelopes of subdwarf B stars, diffusive movements will considerably change the envelope structure and the surface abundances on a short timescale. Also, the subdwarfs will inherit the effects of diffusion in their direct progenitors, namely giants near the tip of the red giant branch. This will influence the global evolution and the pulsational properties of subdwarf B stars. We investigate the impact of gravitational settling, thermal diffusion and concentration diffusion on the evolution and pulsations of subdwarf B stars. Our diffusive stellar models are compared with models evolved without diffusion. We constructed subdwarf B models with a mass of 0.465 Msun from a 1 and 3 Msun ZAMS progenitor. The low mass star ignited helium in an energetic flash, while the intermediate mass star started helium fusion gently. For each progenitor type we computed series with and without atomic diffusion. Atomic diffusion in red giants causes the helium core mass at the onset of helium ignition to be larger. We find an increase of 0.0015 Msun for the 1 Msun model and 0.0036 Msun for the 3 Msun model. The effects on the red giant surface abundances are small after the first dredge up. The evolutionary tracks of the diffusive subdwarf B models are shifted to lower surface gravities and effective temperatures due to outward diffusion of hydrogen. This affects both the frequencies of the excited modes and the overall frequency spectrum. Especially the structure and pulsations of the post-non-degenerate sdB star are drastically altered, proving that atomic diffusion cannot be ignored in these stars.Comment: 10 pages, 6 figures, accepted for publication in A&

Adolescent pregnancy: An important issue for paediatricians and primary care providers-A position paper from the European academy of paediatrics.

Adolescent pregnancy and childbearing, remain a widespread health-related problem with potential short and long-term consequences. Comprehensive social, economic, environmental, structural, and cultural factors heavily impact on adolescents' sexual and reproductive health and early pregnancy. Health professionals can play a pivotal role in the prevention of unplanned pregnancy. Improved access to family planning, sexuality education in schools, community-based interventions, and policies contribute greatly to reduce the risk of adolescent pregnancy and the adoption of respectful and responsible sexual behaviour. Additionally, health care professionals can support pregnant adolescents in making decisions under these circumstances and provide adequate health care. This review highlights actions that can guide healthcare professionals in empowering young adolescents to become more aware and capable of making informed decisions about their sexual life, health, and future