Alternative models for measuring temporal trends in incidence and mortality rates

The average percent change (APC) is often used to measure temporal trends. Under the assumption of linearity on the logarithmic scale, the APC is estimated by using a generalized linear model. A serious limitation of least-squares type estimators is their sensitivity to outliers. The goal of this study is two-fold: firstly, we propose a robust and easy-to-compute measure of the temporal trend based on the median of the rates (median percent change - MPC), rather than their mean; secondly, we investigate the performance of several models for estimating the rate of change when some of the most common model assumptions are violated. We provide some general guidance on the practices of the estimation of temporal trends when using different models under different circumstances. Also, we analyzed an English cancer registration dataset to illustrate the proposed method. The MPC provides a robust alternative to APC. We believe that, as a good practice, both APC and MPC should be presented when sensitivity issues arise. The modelling of data subsets, in any case, should reflect the peculiarity of the process from where the dataset has originated

Hybrid Mechanical Systems

We discuss hybrid systems in which a mechanical oscillator is coupled to another (microscopic) quantum system, such as trapped atoms or ions, solid-state spin qubits, or superconducting devices. We summarize and compare different coupling schemes and describe first experimental implementations. Hybrid mechanical systems enable new approaches to quantum control of mechanical objects, precision sensing, and quantum information processing.Comment: To cite this review, please refer to the published book chapter (see Journal-ref and DOI). This v2 corresponds to the published versio

Probing the strength of infants' preference for helpers over hinderers: two replication attempts of Hamlin and Wynn (2011)

Several studies indicate that infants prefer individuals who act prosocially over those who act antisocially toward unrelated third parties. In the present study, we focused on a paradigm published by Kiley Hamlin and Karen Wynn in 2011. In this study, infants were habituated to a live puppet show in which a protagonist tried to open a box to retrieve a toy placed inside. The protagonist was either helped by a second puppet (the “Helper”), or hindered by a third puppet (the “Hinderer”). At test, infants were presented with the Helper and the Hinderer, and encouraged to reach for one of them. In the original study, 75% of 9-month-olds selected the Helper, arguably demonstrating a preference for prosocial over antisocial individuals. We conducted two studies with the aim of replicating this result. Each attempt was performed by a different group of experimenters. Study 1 followed the methods of the published study as faithfully as possible. Study 2 introduced slight modifications to the stimuli and the procedure following the guidelines generously provided by Kiley Hamlin and her collaborators. Yet, in our replication attempts, 9-month-olds’ preference for helpers over hinderers did not differ significantly from chance (62.5% and 50%, respectively, in Studies 1 and 2). Two types of factors could explain why our results differed from those of Hamlin and Wynn: minor methodological dissimilarities (in procedure, materials, or the population tested), or the effect size being smaller than originally assumed. We conclude that fine methodological details that are crucial to infants’ success in this task need to be identified to ensure the replicability of the original result

The influence of postgraduate qualifications on educational identity formation of healthcare professionals

Demand for postgraduate qualifications in medical education can be judged by the increase in providers worldwide over the last two decades. However, research into the impact of such courses on identity formation of healthcare professionals is limited. This study investigates the influence of such programmes on graduates’ educational identities, practices and career progression. Informed by constructivist grounded theory (CGT), semi-structured interviews were conducted with 27 graduates (2008–2012) from one postgraduate programme, who were at different stages in their careers worldwide. The audio data were transcribed and analysed using a CGT approach. Participants enrolled in award-bearing medical education courses for various intrinsic and extrinsic reasons. The findings from this study highlight their development as educators, and educational researchers, leaders and learners, as their self-efficacy in educational practices and engagement in scholarly activities increased. Graduates attributed career progression to the qualification, with many being promoted into senior positions. They also described substantial performance attainments in the workplace. The findings contribute to understanding the complexity and nuances of educational identity formation of healthcare professionals. A qualification in medical education encouraged transformational changes and epistemological development as an educator. Awareness of these findings will inform both those considering enrolment and those supporting them of potential benefits of these programmes

Survival from cancer in teenagers and young adults in England, 1979–2003

Cancer is the leading cause of disease-related death in teenagers and young adults aged 13–24 years (TYAs) in England. We have analysed national 5-year relative survival among more than 30 000 incident cancer cases in TYAs. For cancer overall, 5-year survival improved from 63% in 1979–84 to 74% during 1996–2001 (P<0.001). However, there were no sustained improvements in survival over time among high-grade brain tumours and bone and soft tissue sarcomas. Survival patterns varied by age group (13–16, 17–20, 21–24 years), sex and diagnosis. Survival from leukaemia and brain tumours was better in the youngest age group but in the oldest from germ-cell tumours (GCTs). For lymphomas, bone and soft tissue sarcomas, melanoma and carcinomas, survival was not significantly associated with age. Females had a better survival than males except for GCTs. Most groups showed no association between survival and socioeconomic deprivation, but for leukaemias, head and neck carcinoma and colorectal carcinoma, survival was significantly poorer with increasing deprivation. These results will aid the development of national specialised service provision for this age group and identify areas of clinical need that present the greatest challenges

Tests of chameleon gravity

Theories of modified gravity, where light scalars with non-trivial self-interactions and non-minimal couplings to matter—chameleon and symmetron theories—dynamically suppress deviations from general relativity in the solar system. On other scales, the environmental nature of the screening means that such scalars may be relevant. The highly-nonlinear nature of screening mechanisms means that they evade classical fifth-force searches, and there has been an intense effort towards designing new and novel tests to probe them, both in the laboratory and using astrophysical objects, and by reinterpreting existing datasets. The results of these searches are often presented using different parametrizations, which can make it difficult to compare constraints coming from different probes. The purpose of this review is to summarize the present state-of-the-art searches for screened scalars coupled to matter, and to translate the current bounds into a single parametrization to survey the state of the models. Presently, commonly studied chameleon models are well-constrained but less commonly studied models have large regions of parameter space that are still viable. Symmetron models are constrained well by astrophysical and laboratory tests, but there is a desert separating the two scales where the model is unconstrained. The coupling of chameleons to photons is tightly constrained but the symmetron coupling has yet to be explored. We also summarize the current bounds on f(R) models that exhibit the chameleon mechanism (Hu and Sawicki models). The simplest of these are well constrained by astrophysical probes, but there are currently few reported bounds for theories with higher powers of R. The review ends by discussing the future prospects for constraining screened modified gravity models further using upcoming and planned experiments

Comorbidity, age, race and stage at diagnosis in colorectal cancer: a retrospective, parallel analysis of two health systems

© 2008 Zafar et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Background : Stage at diagnosis plays a significant role in colorectal cancer (CRC) survival. Understanding which factors contribute to a more advanced stage at diagnosis is vital to improving overall survival. Comorbidity, race, and age are known to impact receipt of cancer therapy and survival, but the relationship of these factors to stage at diagnosis of CRC is less clear. The objective of this study is to investigate how comorbidity, race and age influence stage of CRC diagnosis. Methods : Two distinct healthcare populations in the United States (US) were retrospectively studied. Using the Cancer Care Outcomes Research and Surveillance Consortium database, we identified CRC patients treated at 15 Veterans Administration (VA) hospitals from 2003–2007. We assessed metastatic CRC patients treated from 2003–2006 at 10 non-VA, fee-for-service (FFS) practices. Stage at diagnosis was dichotomized (non-metastatic, metastatic). Race was dichotomized (white, non-white). Charlson comorbidity index and age at diagnosis were calculated. Associations between stage, comorbidity, race, and age were determined by logistic regression. Results : 342 VA and 340 FFS patients were included. Populations differed by the proportion of patients with metastatic CRC at diagnosis (VA 27% and FFS 77%) reflecting differences in eligibility criteria for inclusion. VA patients were mean (standard deviation; SD) age 67 (11), Charlson index 2.0 (1.0), and were 63% white. FFS patients were mean age 61 (13), Charlson index 1.6 (1.0), and were 73% white. In the VA cohort, higher comorbidity was associated with earlier stage at diagnosis after adjusting for age and race (odds ratio (OR) 0.76, 95% confidence interval (CI) 0.58–1.00; p = 0.045); no such significant relationship was identified in the FFS cohort (OR 1.09, 95% CI 0.82–1.44; p = 0.57). In both cohorts, no association was found between stage at diagnosis and either age or race. Conclusion : Higher comorbidity may lead to earlier stage of CRC diagnosis. Multiple factors, perhaps including increased interactions with the healthcare system due to comorbidity, might contribute to this finding. Such increased interactions are seen among patients within a healthcare system like the VA system in the US versus sporadic interactions which may be seen with FFS healthcare

Geographical and temporal distribution of cancer survival in teenagers and young adults in England

Background:Between 1979 and 2001, an analysis of cancer survival in young people in England, aged 13 to 24 years, showed overall improvements. However, for some diagnostic groups, little or no increases were observed. The aim of this study was to analyse the regional distribution of cancer survival in teenagers and young adults in England in order to identify patterns and potential for improvements at a regional scale.Methods:We examined geographical and temporal patterns in relative survival in cancer patients aged 13-24 years in England during the time period 1979-2001. Cancer cases were grouped according to an internationally recognised morphology-based diagnostic scheme.Results:For most diagnostic groups, there was little variation in survival between regions, except for testicular germ cell tumours (P0.006) and colorectal carcinoma (P0.002). For certain diagnostic groups, the temporal pattern in survival differed between regions. However, in regions that showed poor survival during the early part of the study period, greatest improvements were observed in groups such as acute lymphoid leukaemia, acute myeloid leukaemia, testicular tumours and melanoma.Conclusion:In conclusion, there was a reduction in the differences in survival between regions during the study period. © 2009 Cancer Research UK

Rates of inclusion of teenagers and young adults in England into National Cancer Research Network clinical trials: Report from the National Cancer Research Institute (NCRI) Teenage and Young Adult Clinical Studies Development Group

Poor inclusion rates into clinical trials for teenagers and young adults (TYA; aged 13–24 years) have been assumed but not systematically investigated in England. We analysed accrual rates (AR) from 1 April 2005 up to 31 March 2007 to National Cancer Research Network (NCRN) Phase III trials for the commonest tumour types occurring in TYA and children: leukaemia, lymphoma, brain and central nervous system, bone sarcomas and male germ cell tumours. AR for 2005–2007 were 43.2% for patients aged 10–14 years, 25.2% for patients aged 15–19 years, and 13.1% for patients aged 20–24 years in the tumour types analysed. Compared with accrual from 1 April 2005 to 31 March 2006, AR between 1 April 2006 and 31 March 2007 increased for those aged 10–14 and 15–19 years, but fell for those aged 20–24 years. AR varied considerably among cancer types. Despite four trials being available, patients over 16 years with central nervous system tumours were not recruited. Rates of participation in clinical trials in England from 2005 to 2007 were much lower for TYA older than 15 years compared with children and younger teenagers. The variations in open trials, trial age eligibility criteria and extent of trial activation in treatment centres in part explain this observation. Other possible influences, such as difficulties associated with the consent of TYA require further evaluation. Closer dialogue between those involved in planning and running trials for children and for adults is necessary to improve trial availability and recruitment. Further research is required to identify trends in trial availability and accrual for those tumours constituting the remaining 26% of TYA cancers

Cancer mortality in 13 to 29-year-olds in England and Wales, 1981–2005

We examined cancer mortality at ages 13–29 years in England and Wales between 1981 and 2005, a total of 20 026 deaths over approximately 303 million person-years (mpy) at risk by sex, age group and time period. Overall, the mortality rate was 65.6 per mpy. Malignant neoplasms of the central nervous system showed the highest rate (8.5), followed by myeloid and monocytic leukaemia (6.6), lymphoid leukaemia (6.4), malignant bone tumours (5.4) and non-Hodgkin's lymphoma (5.2). These groups together accounted for almost 50% of all cancer deaths. The mortality rate for males (72.4) was 23% higher than for females (58.6) (P-value <0.0001). Males showed significantly higher mortality rates than females in almost all diagnostic groups, in general, mortality increasing with age (P-value <0.0001). There were significant decreases in mortality over time, the annual percentage change between 1981 and 2005 being minus 1.86 (95% confidence interval −2.09 to −1.62). Cancer groups with the highest mortality differed from those with the highest incidence