Evaluation of a standard provision versus an autonomy promotive exercise referral programme: rationale and study design

Background The National Institute of Clinical Excellence in the UK has recommended that the effectiveness of ongoing exercise referral schemes to promote physical activity should be examined in research trials. Recent empirical evidence in health care and physical activity promotion contexts provides a foundation for testing the utility of a Self Determination Theory (SDT) -based exercise referral consultation. Methods/Design Design: An exploratory cluster randomised controlled trial comparing standard provision exercise on prescription with a Self Determination Theory-based (SDT) exercise on prescription intervention. Participants: 347 people referred to the Birmingham Exercise on Prescription scheme between November 2007 and July 2008. The 13 exercise on prescription sites in Birmingham were randomised to current practice (n=7) or to the SDT-based intervention (n=6). Outcomes measured at 3 and 6-months: Minutes of moderate or vigorous physical activity per week assessed using the 7-day Physical Activity Recall; physical health: blood pressure and weight; health status measured using the Dartmouth CO-OP charts; anxiety and depression measured by the Hospital Anxiety and Depression Scale and vitality measured by the subjective vitality score; motivation and processes of change: perceptions of autonomy support from the advisor, satisfaction of the needs for competence, autonomy, and relatedness via physical activity, and motivational regulations for exercise. Discussion This trial will determine whether an exercise referral programme based on Self Determination Theory increases physical activity and other health outcomes compared to a standard programme and will test the underlying SDT-based process model (perceived autonomy support, need satisfaction, motivation regulations, outcomes) via structural equation modelling. Trial registration The trial is registered as Current Controlled trials ISRCTN07682833

Computational Models of Classical Conditioning guest editors’ introduction

In the present special issue, the performance of current computational models of classical conditioning was evaluated under three requirements: (1) Models were to be tested against a list of previously agreed-upon phenomena; (2) the parameters were fixed across simulations; and (3) the simulations used to test the models had to be made available. These requirements resulted in three major products: (a) a list of fundamental classical-conditioning results for which there is a consensus about their reliability; (b) the necessary information to evaluate each of the models on the basis of its ordinal successes in accounting for the experimental data; and (c) a repository of computational models ready to generate simulations. We believe that the contents of this issue represent the 2012 state of the art in computational modeling of classical conditioning and provide a way to find promising avenues for future model development

A Rescorla-Wagner Drift-Diffusion Model of Conditioning and Timing

Computational models of classical conditioning have made significant contributions to the theoretic understanding of associative learning, yet they still struggle when the temporal aspects of conditioning are taken into account. Interval timing models have contributed a rich variety of time representations and provided accurate predictions for the timing of responses, but they usually have little to say about associative learning. In this article we present a unified model of conditioning and timing that is based on the influential Rescorla-Wagner conditioning model and the more recently developed Timing Drift-Diffusion model. We test the model by simulating 10 experimental phenomena and show that it can provide an adequate account for 8, and a partial account for the other 2. We argue that the model can account for more phenomena in the chosen set than these other similar in scope models: CSC-TD, MS-TD, Learning to Time and Modular Theory. A comparison and analysis of the mechanisms in these models is provided, with a focus on the types of time representation and associative learning rule used

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Glucocorticoid Receptor-Dependent Gene Regulatory Networks

While the molecular mechanisms of glucocorticoid regulation of transcription have been studied in detail, the global networks regulated by the glucocorticoid receptor (GR) remain unknown. To address this question, we performed an orthogonal analysis to identify direct targets of the GR. First, we analyzed the expression profile of mouse livers in the presence or absence of exogenous glucocorticoid, resulting in over 1,300 differentially expressed genes. We then executed genome-wide location analysis on chromatin from the same livers, identifying more than 300 promoters that are bound by the GR. Intersecting the two lists yielded 53 genes whose expression is functionally dependent upon the ligand-bound GR. Further network and sequence analysis of the functional targets enabled us to suggest interactions between the GR and other transcription factors at specific target genes. Together, our results further our understanding of the GR and its targets, and provide the basis for more targeted glucocorticoid therapies

Validation of Case-Finding Algorithms Derived from Administrative Data for Identifying Adults Living with Human Immunodeficiency Virus Infection

OBJECTIVE: We sought to validate a case-finding algorithm for human immunodeficiency virus (HIV) infection using administrative health databases in Ontario, Canada. METHODS: We constructed 48 case-finding algorithms using combinations of physician billing claims, hospital and emergency room separations and prescription drug claims. We determined the test characteristics of each algorithm over various time frames for identifying HIV infection, using data abstracted from the charts of 2,040 randomly selected patients receiving care at two medical practices in Toronto, Ontario as the reference standard. RESULTS: With the exception of algorithms using only a single physician claim, the specificity of all algorithms exceeded 99%. An algorithm consisting of three physician claims over a three year period had a sensitivity and specificity of 96.2% (95% CI 95.2%-97.9%) and 99.6% (95% CI 99.1%-99.8%), respectively. Application of the algorithm to the province of Ontario identified 12,179 HIV-infected patients in care for the period spanning April 1, 2007 to March 31, 2009. CONCLUSIONS: Case-finding algorithms generated from administrative data can accurately identify adults living with HIV. A relatively simple "3 claims in 3 years" definition can be used for assembling a population-based cohort and facilitating future research examining trends in health service use and outcomes among HIV-infected adults in Ontario

Checkerboard Patterns, Interspecific Competition, and Extinction: Lessons from Distribution Patterns of Tarsiers (Tarsius) and Slow Lorises (Nycticebus) in Insular Southeast Asia

Tarsiers (Tarsius) and slow lorises (Nycticebus) are the only extant nocturnal primates occurring in Southeast Asia. Harcourt (1999) hypothesized that in insular Southeast Asia, slow lorises and tarsiers showed a checkerboard distribution on 12 small (<12,000 km2) islands, i.e., only one or the other occurs, and attributed this to extreme levels of competition between these 2 largely faunivorous primates. Further, he predicted slow lorises were able to persist on smaller islands than tarsiers. We re-evaluated these findings using an expanded dataset including 49 islands where tarsiers or slow lorises occur. Tarsiers and slow lorises live on islands of similar size (median size of ca. 300–900 km2), and both taxa inhabit an equal proportion of small, medium, and large islands. On small islands within their area of sympatry tarsiers occur on 1 island, slow lorises on 8, both genera on 3, and we can assume they have become extinct from 11 small islands since the Last Glacial Maximum. Sizes of islands where tarsiers or slow lorises have become extinct do not differ from islands where they are still extant. We show that slow lorises occur on more islands in insular Southeast Asia than perhaps previously assumed, but these islands are not smaller on average than islands where tarsiers occur. A checkerboard distribution between these taxa is not evident. More studies are needed at the macroecological level to assess the importance of biogeographic history in explaining their present-day distribution patterns

Effect of training-sample size and classification difficulty on the accuracy of genomic predictors

Introduction: As part of the MicroArray Quality Control (MAQC)-II project, this analysis examines how the choice of univariate feature-selection methods and classification algorithms may influence the performance of genomic predictors under varying degrees of prediction difficulty represented by three clinically relevant endpoints. Methods: We used gene-expression data from 230 breast cancers (grouped into training and independent validation sets), and we examined 40 predictors (five univariate feature-selection methods combined with eight different classifiers) for each of the three endpoints. Their classification performance was estimated on the training set by using two different resampling methods and compared with the accuracy observed in the independent validation set. Results: A ranking of the three classification problems was obtained, and the performance of 120 models was estimated and assessed on an independent validation set. The bootstrapping estimates were closer to the validation performance than were the cross-validation estimates. The required sample size for each endpoint was estimated, and both gene-level and pathway-level analyses were performed on the obtained models. Conclusions: We showed that genomic predictor accuracy is determined largely by an interplay between sample size and classification difficulty. Variations on univariate feature-selection methods and choice of classification algorithm have only a modest impact on predictor performance, and several statistically equally good predictors can be developed for any given classification problem

Addiction Treatment and Stable Housing among a Cohort of Injection Drug Users

Background: Unstable housing and homelessness is prevalent among injection drug users (IDU). We sought to examine whether accessing addiction treatment was associated with attaining stable housing in a prospective cohort of IDU in Vancouver, Canada. Methods: We used data collected via the Vancouver Injection Drug User Study (VIDUS) between December 2005 and April 2010. Attaining stable housing was defined as two consecutive ‘‘stable housing’ ’ designations (i.e., living in an apartment or house) during the follow-up period. We assessed exposure to addiction treatment in the interview prior to the attainment of stable housing among participants who were homeless or living in single room occupancy (SRO) hotels at baseline. Bivariate and multivariate associations between the baseline and time-updated characteristics and attaining stable housing were examined using Cox proportional hazard regression models. Principal Findings: Of the 992 IDU eligible for this analysis, 495 (49.9%) reported being homeless, 497 (50.1%) resided in SRO hotels, and 380 (38.3%) were enrolled in addiction treatment at the baseline interview. Only 211 (21.3%) attained stable housing during the follow-up period and of this group, 69 (32.7%) had addiction treatment exposure prior to achieving stable housing. Addiction treatment was inversely associated with attaining stable housing in a multivariate model (adjusted hazard ratio [AHR] = 0.71; 95 % CI: 0.52–0.96). Being in a partnered relationship was positively associated with the primary outcom

Revisión de la literatura integradora acerca de intervenciones de la enfermería volcadas hacia el incremento del autocuidado entre pacientes con insuficiencia cardiaca

Objective: to analyze and summarize knowledge concerning critical components of interventions that have been proposed and implemented by nurses with the aim of optimizing self-care by heart failure patients.Methods: PubMed and CINAHL were the electronic databases used to search full peer-reviewed papers, presenting descriptions of nursing interventions directed to patients or to patients and their families and designed to optimize self-care. Forty-two studies were included in the final sample (n=4,799 patients).Results: this review pointed to a variety and complexity of nursing interventions. As self-care encompasses several behaviors, interventions targeted an average of 3.6 behaviors. Educational/counselling activities were combined or not with cognitive behavioral strategies, but only about half of the studies used a theoretical background to guide interventions. Clinical assessment and management were frequently associated with self-care interventions, which varied in number of sessions (1 to 30); length of follow-up (2 weeks to 12 months) and endpoints.Conclusions: these findings may be useful to inform nurses about further research in self-care interventions in order to propose the comparison of different modalities of intervention, the use of theoretical background and the establishment of endpoints to evaluate their effectiveness.Objetivo:analisar e sintetizar o conchecimento relacionado aos componentes críticos das intervençoes que têm, sido propostas e implementadas por enfermeiros(as) com objetivo de optimizar o auto-cuidado de pacientes portadores de insuficiência cardíaca.Método:PubMed e CINAHL foram as bases de dados electrônicas utilizadas para investigar artigos revisados por pares (peer review), apresentando as descrições das intervenções dirigidas ao paciente ou ao paciente e sua familia, visando melhorar o auto-cuidado. Foram incluídos 42 estudos na amostra final (n=4799 pacientes).Resultados:esta revisão apontou variedade e complexidade das intervenções de enfermagem. Como o auto-cuidado envolve diferentes comportamentos, as intervenções visaram em média 3,6 comportamentos. As Atividades de educação e aconselhamento foram combinadas ou não com estratégias cognitivo-comportamentais, mas somente a metade dos estudos utilizaram suporte teórico para guiar as intervenções. A avaliação e o manejo clínico foram frequentemente associados às intervenções de auto-cuidado, as quais variam em número de sessões (1 a 30), duração do seguimento (2 semanas a 12 meses) e desfechos.Conclusão:estes resultados podem ser úteis para guiar os enfermeiros no que se refere à futuros estudos sobre intervenções de auto-cuidado, de maneira a propor a comparação de diferentes modalidades de intervenção, uso de suporte teórico e estabelecimento de desfechos para melhor avaliar sua eficácia.Objetivo:analizar y sintetizar el conocimiento relacionado a componentes críticos de intervenciones que han sido propuestas e implementadas por enfermeros(as) con el objetivo de optimizar el autocuidado entre pacientes con insuficiencia cardiaca.Método:PUBMED y CINAHL han sido las bases de datos electrónicas usadas para investigar artículos revisados por pares (peer review), presentando descripciones de intervenciones destinadas a perfeccionar el autocuidado dirigido al paciente o al paciente y a su familia. Se incluyeron 42 estudios en la muestra final (n=4799 pacientes).Resultados:esta revisión apuntó a una variedad y complejidad de intervenciones de enfermería. Como el autocuidado abarca varios comportamientos, las intervenciones tuvieron como blanco, en media, 3,6 comportamientos. Actividades de educación/consejería fueron combinadas o no con estrategias cognitivo-comportamentales, pero tan solo cerca de la mitad de los estudios tenían aporte teórico para guiar intervenciones. La gestión y la evaluación clínica fueron frecuentemente asociadas a intervenciones de autocuidado, las cuales oscilaron en número de sesiones (1 a 30), duración del seguimiento (2 semanas a 12 meses) y objetivos.Conclusiones:estos resultados pueden ser útiles para informar a las enfermeras acerca de nuevas investigaciones en intervenciones de autocuidado, de modo a proponer la comparación de distintas modalidades de intervención, el uso de un aporte teórico y el establecimiento de objetivos para evaluar su eficacia