Estimating the impact of influenza vaccination and antigenic drift on influenza-related morbidity and mortality in England & Wales using hidden Markov models

Influenza causes substantial morbidity and mortality in some influenza sea- sons, especially among the elderly. Influenza seasons dominated by circula- tion of influenza A/H3N2 virus tend to result in more morbidity and mor- tality than seasons dominated by influenza A/H1N1 or influenza B viruses. Influenza viruses undergo constant mutation, called antigenic drift, which is largely driven by host immunity. It has been shown that antigenic drift in influenza A/H3N2 virus proceeds in a punctuated, as opposed to contin- uous, fashion. A cluster of antigenically similar influenza A/H3N2 viruses appears to remain dominant for between 1 and 8 influenza seasons before being supplanted by a new cluster. Influenza seasons when a new cluster becomes dominant may result in higher morbidity and mortality than other seasons. Influenza vaccine effectiveness varies between influenza seasons be- cause of the different subtypes in circulation and the degree of antigenic match between vaccine and circulating variants. In each influenza season in recent years, over 70% of the population of England & Wales aged > 65 has been vaccinated, though the impact of this high coverage on population level morbidity and mortality is unknown. Multivariate time series models were fitted to reports of laboratory confirmed influenza, sentinel general practi- tioner (GP) consultations for influenza-like-illness, and all deaths registered to underlying pneumonia or influenza in England & Wales from 1975/76 to 2004/05. The models successfully distinguish influenza - attributable GP consultations and deaths from GP consultations and deaths that would be expected in the absence of influenza. This distinction is made jointly by the laboratory reports and the non-laboratory confirmed surveillance data. It is not possible to use the multivariate time series models to quantify the average effect of the appearance of a new cluster of influenza A/H3N2 virus variants, or vaccine impact, on influenza - attributable morbidity or mortality in the data analyzed. Reasons for this are discu

Care relationships in social interventions: a critical realist analysis

Concepts of personalisation and person-centred care have been a long-term focus in health and social care and are increasingly embedded in policy. It is a narrative that is popular with citizens, practitioners, and leaders as it encapsulates an aspiration for responsive care, sensitive to our own unique priorities and circumstances. Existing research reveals that effective person-centred care involves a meshing of principles and practice: ways of both ‘doing’ person-centred care and ‘being’ person-centred. If we limit ourselves to focus primarily on ways of ‘doing’ person-centred care, we risk overlooking the role of personhood and relationship and undervaluing important, albeit invisible, causal mechanisms. The value of people and relationships is noted in person-centred research and policy; however, this thesis argues that its inclusion is not adequately theoretically supported. This research employs Critical Realism, Archer's Realist Social Theory and Donati's Relational Sociology to reconceptualise the role of relationships between carers and care recipients in four social interventions; a support service for people with mild to moderate mental ill-health, a personal budget support service, a community sports intervention for young people, and family-based care and support for disabled people. It employs mixed methods, in a comparative case study methodology to explore whether, how, and under what conditions relationships that are established between carers and care recipients can foster personal reflexivity and generate relational goods. By operationalising Archer’s and Donati’s theory in practice contexts, this research delivers new theoretical support for the proposition that care relationships can have causal effects, given facilitative conditions. This work demonstrates the value of Archer’s theories of personhood and reflexivity to empirical research, applying these concepts to explore how the biographically formed identity and reflexive tendencies of each person are implicated in care relationships, and how organisation and system factors can be influential. The thesis contributes new conceptual tools that can support our understanding of the nature and role of care relationships and the conditions that support them, namely: the Relational/Reflexive Mechanism (RRM) model that visually captures how relationships are implicated in personal change, and the Orientation to Relational Reflexivity and Agency for Change (ORRAC) model, a contribution to Realist Sociology that can be used to qualitatively discern and track key aspects of a subject’s reflexivity over time. Building on the ORRAC model, this work also redescribes the requirements set out in Donati’s Relational Sociology for the generation of Relational Goods, in respect of care and support relationships, further enabling theorisation of relational configurations and their influence on the reflexive powers of individuals. The application of these research findings offers the potential for their practical application in social interventions and beyond

Predictive powers of chiral perturbation theory in Compton scattering off protons

We study low-energy nucleon Compton scattering in the framework of baryon chiral perturbation theory (B$\chi$PT) with pion, nucleon, and $\Delta$(1232) degrees of freedom, up to and including the next-to-next-to-leading order (NNLO). We include the effects of order $p^2$, $p^3$ and $p^4/\varDelta$, with $\varDelta\approx 300$ MeV the $\Delta$-resonance excitation energy. These are all "predictive" powers in the sense that no unknown low-energy constants enter until at least one order higher (i.e, $p^4$). Estimating the theoretical uncertainty on the basis of natural size for $p^4$ effects, we find that uncertainty of such a NNLO result is comparable to the uncertainty of the present experimental data for low-energy Compton scattering. We find an excellent agreement with the experimental cross section data up to at least the pion-production threshold. Nevertheless, for the proton's magnetic polarizability we obtain a value of $(4.0\pm 0.7)\times 10^{-4}$ fm$^3$, in significant disagreement with the current PDG value. Unlike the previous $\chi$PT studies of Compton scattering, we perform the calculations in a manifestly Lorentz-covariant fashion, refraining from the heavy-baryon (HB) expansion. The difference between the lowest order HB$\chi$PT and B$\chi$PT results for polarizabilities is found to be appreciable. We discuss the chiral behavior of proton polarizabilities in both HB$\chi$PT and B$\chi$PT with the hope to confront it with lattice QCD calculations in a near future. In studying some of the polarized observables, we identify the regime where their naive low-energy expansion begins to break down, thus addressing the forthcoming precision measurements at the HIGS facility.Comment: 24 pages, 9 figures, RevTeX4, revised version published in EPJ

Facilitating the transition of young people with long-term conditions through health services from childhood to adulthood: the Transition research programme

Background: As young people with long-term conditions move from childhood to adulthood, their health may deteriorate and their social participation may reduce. ‘Transition’ is the ‘process’ that addresses the medical, psychosocial and educational needs of young people during this time. ‘Transfer’ is the ‘event’ when medical care moves from children’s to adults’ services. In a typical NHS Trust serving a population of 270,000, approximately 100 young people with long-term conditions requiring secondary care reach the age of 16 years each year. As transition extends over about 7 years, the number in transition at any time is approximately 700. Objectives: Purpose – to promote the health and well-being of young people with long-term conditions by generating evidence to enable NHS commissioners and providers to facilitate successful health-care transition. Objectives – (1) to work with young people to determine what is important in their transitional health care, (2) to identify the effective and efficient features of transitional health care and (3) to determine how transitional health care should be commissioned and provided. Design, settings and participants: Three work packages addressed each objective. Objective 1. (i) A young people’s advisory group met monthly throughout the programme. (ii) It explored the usefulness of patient-held health information. (iii) A ‘Q-sort’ study examined how young people approached transitional health care. Objective 2. (i) We followed, for 3 years, 374 young people with type 1 diabetes mellitus (150 from five sites in England), autism spectrum disorder (118 from four sites in England) or cerebral palsy (106 from 18 sites in England and Northern Ireland). We assessed whether or not nine proposed beneficial features (PBFs) of transitional health care predicted better outcomes. (ii) We interviewed a subset of 13 young people about their transition. (iii) We undertook a discrete choice experiment and examined the efficiency of illustrative models of transition. Objective 3. (i) We interviewed staff and observed meetings in three trusts to identify the facilitators of and barriers to introducing developmentally appropriate health care (DAH). We developed a toolkit to assist the introduction of DAH. (ii) We undertook a literature review, interviews and site visits to identify the facilitators of and barriers to commissioning transitional health care. (iii) We synthesised learning on ‘what’ and ‘how’ to commission, drawing on meetings with commissioners. Main outcome measures: Participation in life situations, mental well-being, satisfaction with services and condition-specific outcomes. Strengths: This was a longitudinal study with a large sample; the conditions chosen were representative; non-participation and attrition appeared unlikely to introduce bias; the research on commissioning was novel; and a young person’s group was involved. Limitations: There is uncertainty about whether or not the regions and trusts in the longitudinal study were representative; however, we recruited from 27 trusts widely spread over England and Northern Ireland, which varied greatly in the number and variety of the PBFs they offered. The quality of delivery of each PBF was not assessed. Owing to the nature of the data, only exploratory rather than strict economic modelling was undertaken. Results and conclusions: (1) Commissioners and providers regarded transition as the responsibility of children’s services. This is inappropriate, given that transition extends to approximately the age of 24 years. Our findings indicate an important role for commissioners of adults’ services to commission transitional health care, in addition to commissioners of children’s services with whom responsibility for transitional health care currently lies. (2) DAH is a crucial aspect of transitional health care. Our findings indicate the importance of health services being commissioned to ensure that providers deliver DAH across all health-care services, and that this will be facilitated by commitment from senior provider and commissioner leaders. (3) Good practice led by enthusiasts rarely generalised to other specialties or to adults’ services. This indicates the importance of NHS Trusts adopting a trust-wide approach to implementation of transitional health care. (4) Adults’ and children’s services were often not joined up. This indicates the importance of adults’ clinicians, children’s clinicians and general practitioners planning transition procedures together. (5) Young people adopted one of four broad interaction styles during transition: ‘laid back’, ‘anxious’, ‘wanting autonomy’ or ‘socially oriented’. Identifying a young person’s style would help personalise communication with them. (6) Three PBFs of transitional health care were significantly associated with better outcomes: ‘parental involvement, suiting parent and young person’, ‘promotion of a young person’s confidence in managing their health’ and ‘meeting the adult team before transfer’. (7) Maximal service uptake would be achieved by services encouraging appropriate parental involvement with young people to make decisions about their care. A service involving ‘appropriate parental involvement’ and ‘promotion of confidence in managing one’s health’ may offer good value for money. Future work: How might the programme’s findings be implemented by commissioners and health-care providers? What are the most effective ways for primary health care to assist transition and support young people after transfer

Stellar Diameters and Temperatures VI. High angular resolution measurements of the transiting exoplanet host stars HD 189733 and HD 209458 and implications for models of cool dwarfs

We present direct radii measurements of the well-known transiting exoplanet host stars HD 189733 and HD 209458 using the CHARA Array interferometer. We find the limb-darkened angular diameters to be theta_LD = 0.3848 +/- 0.0055 and 0.2254 +/- 0.0072 milliarcsec for HD 189733 and HD 209458, respectively. HD 189733 and HD 209458 are currently the only two transiting exoplanet systems where detection of the respective planetary companion's orbital motion from high resolution spectroscopy has revealed absolute masses for both star and planet. We use our new measurements together with the orbital information from radial velocity and photometric time series data, Hipparcos distances, and newly measured bolometric fluxes to determine the stellar effective temperatures (T_eff = 4875 +/- 43, 6093 +/- 103 K), stellar linear radii (R_* = 0.805 +/- 0.016, 1.203 +/- 0.061 R_sun), mean stellar densities (rho_* = 1.62 +/- 0.11, 0.58 +/- 0.14 rho_sun), planetary radii (R_p = 1.216 +/- 0.024, 1.451 +/- 0.074 R_Jup), and mean planetary densities (rho_p = 0.605 +/- 0.029, 0.196 +/- 0.033 rho_Jup) for HD 189733 b and HD 209458 b, respectively. The stellar parameters for HD 209458, a F9 dwarf, are consistent with indirect estimates derived from spectroscopic and evolutionary modeling. However, we find that models are unable to reproduce the observational results for the K2 dwarf, HD 189733. We show that, for stellar evolutionary models to match the observed stellar properties of HD 189733, adjustments lowering the solar-calibrated mixing length parameter from 1.83 to 1.34 need to be employed