Can we use the approaches of ecological inference to learn about the potential for dependence bias in dualsystem estimation? An application to cancer registration data

The dual-system estimator, or estimators with a similar underlying set of assumptions and structure, is a widely used approach to estimate the unknown size of a population. Within official statistics its use is linked with population census, while in health applications it is often used to estimate true levels of incidence from imperfect reporting systems; the classic example being work by Sekar and Deming exploring the estimation of births in India in the 1940s. Critical to the implementation of dual-system estimation are the assumptions that the probability of being counted in a source is homogeneous and that the event of being counted in each source is independent. When either of these assumptions fails, the two by two table will have an odds ratio different to one and the dual-system estimator will be biased. Inferential frameworks such as the aggregate association index (AAI) have been developed to allow the researcher to assess the plausibility of independence between two variables in a two by two table, when only the margins are observed. Given any appropriate measure of relationship, this strategy relies on determining the AAI, which provides an indication of the likely association structure between the variables given only the marginal information. Further advances of the AAI have also been established including its link with the odds ratio and its relationship with the size of the study being undertaken. Determining the population size from a two by two table given limited information is an alternative variation of the framework on which the AAI is built. Therefore the underlying theoretical properties of the two by two table are identical in both scenarios – it is only the nature of the unknown information that differs. In this paper we make the first steps to exploring the use of an AAI type framework (and its relatives) to assess the plausibility of an independence assumption in applications of population size estimation. We use alternative data set-ups based on real data relating to historical cancer registration (with three sources of registration) to demonstrate that the chi-square statistic behaves differently over a range of values for the missing data for differing true relationships between the two variables. We then apply the approach to the cancer registration from two of the registration systems to show that we can see evidence of potential dependence from the observed but incomplete data. The first results in this paper demonstrate the possibility of exploring the independence assumption when estimating the unknown population size from two lists. As with the AAI framework, the aim is not to directly estimate the level of the association but rather alert the analyst to the potential for an association and its direction allowing them to assess the likelihood of a biased estimate for the population size. This has important implications within a health setting where it is potentially useful to understand if the true population size, of say cancer patients, is likely to be higher or lower than the estimate constructed assuming independence. Within the official statistics setting, it can alert us to situations where it is advantageous to explore whether external data exist that would allow an adjustment for dependence in our two lists

The Australian Census Longitudinal Dataset: using record linkage to create a longitudinal sample from a series of cross-sections

© 2017 Australian Statistical Publishing Association Inc. Published by John Wiley & Sons Australia Pty Ltd. The Australian Bureau of Statistics is creating a longitudinal sample, called the Australian Census Longitudinal Dataset (ACLD), by linking person records across its five-yearly Census of Population and Housing. This paper proposes a Multi-Panel framework for selecting and weighting records in the ACLD. This framework can be applied more generally to selecting longitudinal samples from a series of cross-sectional administrative files. The proposed framework avoids some significant limitations of the popular ‘Top-Up’ sampling approach to maintaining the cross-sectional and longitudinal representativeness of a sample over time

Chronic disease management support in Australian workplaces—low base, rising need

© 2017 Australian Health Promotion Association Issue addressed: This study investigates the current nature, levels and perceived need for workplace support among mature age Australian workers with chronic illness. Methods: A cross-sectional population survey was conducted via a double opt-in panel sample of Australian workers aged 45 years and older with one or more of six major chronic diseases (diabetes and/or chronic heart, kidney, lung, mental health and/or musculoskeletal conditions). Results: Three hundred and fourteen respondents reported being in the workforce and having at least one of the chronic conditions under investigation, of which almost one third reported having more than one of the conditions. The findings reveal a number of considerable gaps in Australian workplace support for employees 45 years and older with chronic illness, including workplace flexibility, supportive policies and co-worker support. Conclusions: This research adds to a scarce existing literature base on workplace support for workers with chronic illness in Australia. Future research is needed to identify opportunities for effective public policy and implementation of workplace interventions to better support this cohort. So what?: If timely progress is not made in this area, the projected increase in the aged population and scheduled public policy changes impacting retirement age will multiply potential adverse effects on the health of employees with chronic illness and Australia's labour market productivity

Properties of Hadrons in the Nuclear Medium

This review is devoted to the discussion of hadron properties in the nuclear medium and its relation to the partial restoration of chiral symmetry. Special attention is given to disentangle in-medium effects due to conventional many-body interactions from those due to the change of the chiral condensate. In particular, we shall discuss medium effects on the Goldstone bosons (pion, kaon and eta), the vector mesons (rho, omega, phi), and the nucleon. Also, for each proposed in-medium effect the experimental consequence and results will be reviewed.Comment: 43 pages, 8 figures, uses epsf-style file. To appear in Ann. Rev. Nucl. Part. Sci. Vol 4

Small area estimation strategy for the 2011 Census in England and Wales

© 2018-IOS Press and the authors. All rights reserved. The use of model-based small area estimation for adjusting census results in the UK was first introduced in the 2001 Census. The aim was to obtain local level population estimates by age-sex groups, adjusted for the level of undercount that combined results from the Census and the Census Coverage Survey. A similar approach was adopted for the 2011 Census but with new features and this paper describes the work carried out to arrive at the chosen small area strategy. Simulation studies are used to investigate three proposed small area estimation methods: a local fixed effects model (the 2001 Census approach), a direct estimator and a synthetic estimator. The results indicate that both the synthetic and the local fixed effect models constitute good options to produce accurate and reliable local authority population estimates. A proposal is made to implement a small area estimation procedure that accommodates both the synthetic and local fixed models, as in some selected areas with differing local authority under-coverage rates a local fixed effects model may perform best. We examine this strategy under real census conditions based on the final results from the 2011 census

Liver transplantation for type I and type IV glycogen storage disease

Progressive liver failure or hepatic complications of the primary disease led to orthotopic liver transplantation in eight children with glycogen storage disease over a 9-year period. One patient had glycogen storage disease (GSD) type I (von Gierke disease) and seven patients had type IV GSD (Andersen disease). As previously reported [19], a 16.5-year-old-girl with GSD type I was successfully treated in 1982 by orthotopic liver transplantation under cyclosporine and steroid immunosuppression. The metabolic consequences of the disease have been eliminated, the renal function and size have remained normal, and the patient has lived a normal young adult life. A late portal venous thrombosis was treated successfully with a distal splenorenal shunt. Orthotopic liver transplantation was performed in seven children with type N GSD who had progressive hepatic failure. Two patients died early from technical complications. The other five have no evidence of recurrent hepatic amylopectinosis after 1.1–5.8 postoperative years. They have had good physical and intellectual maturation. Amylopectin was found in many extrahepatic tissues prior to surgery, but cardiopathy and skeletal myopathy have not developed after transplantation. Postoperative heart biopsies from patients showed either minimal amylopectin deposits as long as 4.5 years following transplantation or a dramatic reduction in sequential biopsies from one patient who initially had dense myocardial deposits. Serious hepatic derangement is seen most commonly in types T and IV GSD. Liver transplantation cures the hepatic manifestations of both types. The extrahepatic deposition of abnormal glycogen appears not to be problematic in type I disease, and while potentially more threatening in type IV disease, may actually exhibit signs of regression after hepatic allografting

Baryon-Baryon Interactions

After a short survey of some topics of interest in the study of baryon-baryon scattering, the recent Nijmegen energy dependent partial wave analysis (PWA) of the nucleon-nucleon data is reviewed. In this PWA the energy range for both pp and np is now 0 < Tlab < 350 MeV and a chi^2_{d.o.f.}=1.08 was reached. The implications for the pion-nucleon coupling constants are discussed. Comments are made with respect to recent discussions around this coupling constant in the literature. In the second part, we briefly sketch the picture of the baryon in several, more or less QCD-based, quark-models that have been rather prominent in the literature. Inspired by these pictures we constructed a new soft-core model for the nucleon-nucleon interaction and present the first results of this model in a chi^2 -fit to the new multi-energy Nijmegen PWA. With this new model we succeeded in narrowing the gap between theory and experiment at low energies. For the energies Tlab = 25-320 MeV we reached a record low chi^2_{p.d.p.} = 1.16. We finish the paper with some conclusions and an outlook describing the extension of the new model to baryon-baryon scattering.Comment: 12 pages LaTeX and one postscript figure included. Invited talk presented at the XIVth European Conference of Few-Body Problems in Physics, Amsterdam, August 23-28, 199

Flux Discharge Cascades in Various Dimensions

We study the dynamics of electric flux discharge by charged particle pair or spherical string or membrane production in various dimensions. When electric flux wraps at least one compact cycle, we find that a single "pair" production event can initiate a cascading decay in real time that "shorts out" the flux and discharges many units of it. This process arises from local dynamics in the compact space, and so is invisible in the dimensionally-reduced truncation. It occurs in theories as simple as the Schwinger model on a circle, and has implications for any theory with compact dimensions and electric flux, including string theories and the string landscape.Comment: 19+8 pages, 3 figures, 3 appendice