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Selected AbstractsRisk of second malignant neoplasms among childhood cancer survivors treated with radiotherapy: meta-analysis of nine epidemiological studiesPAEDIATRIC & PERINATAL EPIDEMIOLOGY, Issue 4 2009Kazutaka Doi Summary In the light of notable advances made in childhood cancer therapies, an understanding of the late effects of treatment is important for continued medical care. We conducted a meta-analysis of studies on the excess relative risk (ERR) of second malignant neoplasm (SMN) among childhood cancer survivors treated with radiotherapy. Relevant studies were retrieved by searching the PubMed database, supplemented by hand-searching of reference lists of already retrieved papers. Nine studies were identified and overall ERR estimates were calculated using a fixed effects model and a random effects model. The overall ERR per Gy (absorbed dose of ionising radiation) estimates of radiotherapy by a fixed effect model and a random effects model were 0.50 [95% CI 0.20, 1.21] and 0.53 [95% CI 0.22, 1.31] respectively. Heterogeneity among studies was suggested by Cochran's Q statistic (Q = 40.4, d.f. = 8, P < 0.001). The estimate obtained using a random effects model was far smaller than the corresponding estimate of 1.7 [95% CI 1.1, 2.5] from the study on atomic bomb survivors exposed as young children, suggesting underestimation of ERR estimates among the nine studies compared with the estimates from the study of atomic bomb survivors. In view of the heterogeneity and underestimation in ERR estimates, more studies concerning the risk of SMN among childhood cancer survivors are still needed for further understanding of the carcinogenic effects of radiotherapy on children. [source] Lung cancer and regular use of aspirin and nonaspirin nonsteroidal anti-inflammatory drugs,PHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 4 2008Judith P. Kelly RN Abstract Purpose Lung cancer is the leading cause of cancer death in the US. There is evidence of a reduced risk of some cancer sites associated with use of aspirin (ASA) and nonaspirin nonsteroidal anti-inflammatory drugs (NANSAIDs). Our objective was to examine the association of regular use of ASA and NANSAIDs with lung cancer. Methods A hospital-based case,control study of 1884 incident cases of lung cancer and 6251 controls with noncancer diagnoses. Use of ASA and NANSAIDs was considered ,regular' if it occurred on ,4,days/week and lasted for ,3,months. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals. Results The OR for regular use of ASA was 1.1 (0.9,1.4), and the corresponding estimate for regular NANSAID use was 1.0 (0.7,1.3). There was no evidence of decreased risk within strata of age, sex, years of education, or interview year. Examining the association within strata of duration of use, recency of use, cigarette smoking status, pack-years of cigarette smoking, or histologic type of cancer produced no ORs significantly different from 1.0. Conclusions The hypothesis that regular use of ASA or NANSAIDs reduces the risk of lung cancer is not supported by the present data. Copyright © 2007 John Wiley & Sons, Ltd. [source] Does Public Income Induce More Consumption?,THE ECONOMIC RECORD, Issue 272 2010ELLIOTT FAN The Life-Cycle/Permanent Income Hypothesis predicts that income uncertainty reduces an individual's incentive to consume, while holding permanent income level constant. This implies that switching from a relatively unstable form of income to a stable one motivates consumption. This article explores this implication by quantifying and comparing the marginal propensity to consume (MPC) out of private income and income from a public pension scheme. It exploits the introduction of a public pension that provides a monthly fixed amount of payment , a relatively secure source of income. The results suggest that the provision of pension leads to a higher MPC for the beneficiaries' households, and the estimated MPC out of the pension income is significantly larger than the corresponding estimate for private income. Further examination suggests that households facing more non-tradable risks appear to be more prudent on consumption, highlighting the role of income uncertainty in households' consumption decisions. [source] Antipsychotic prescribing trends: a review of pharmaco-epidemiological studiesACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2010H. Verdoux Objective:, To review findings from pharmaco-epidemiological studies exploring antipsychotic (AP) drugs prescribing trends. Method:, We retrieved original studies that explored AP prescribing trends in general population samples since 2000. For each study, we extracted information on sampling method, period, assessment of AP use and corresponding estimates (incidence rates, prevalence rates, pharmacy sales, prescription data) and diagnostic assessment. Results:, Nearly all studies meeting the inclusion criteria (n = 17) showed an increase in AP prescriptions, mainly because of a dramatic rise in second-generation antipsychotics (SGAP) prescriptions. APs are often prescribed for non-psychotic disorders in adults as well as in children and adolescents. Conclusion:, Considering the growing number of persons from the general population exposed to APs, population studies assessing the risk/benefit ratio of SGAP use in disorders other than psychosis are necessary, particularly in children and adolescents. [source] Evaluations of maximization procedures for estimating linkage parameters under heterogeneityGENETIC EPIDEMIOLOGY, Issue 3 2004Swati Biswas Abstract Locus heterogeneity is a major problem plaguing the mapping of disease genes responsible for complex genetic traits via linkage analysis. A common feature of several available methods to account for heterogeneity is that they involve maximizing a multidimensional likelihood to obtain maximum likelihood estimates. The high dimensionality of the likelihood surface may be due to multiple heterogeneity (mixing) parameters, linkage parameters, and/or regression coefficients corresponding to multiple covariates. Here, we focus on this nontrivial computational aspect of incorporating heterogeneity by considering several likelihood maximization procedures, including the expectation maximization (EM) algorithm and the stochastic expectation maximization (SEM) algorithm. The wide applicability of these procedures is demonstrated first through a general formulation of accounting for heterogeneity, and then by applying them to two specific formulations. Furthermore, our simulation studies as well as an application to the Genetic Analysis Workshop 12 asthma datasets show that, among other observations, SEM performs better than EM. As an aside, we illustrate a limitation of the popular admixture approach for incorporating heterogeneity, proved elsewhere. We also show how to obtain standard errors (SEs) for EM and SEM estimates, using methods available in the literature. These SEs can then be combined with the corresponding estimates to provide confidence intervals of the parameters. © 2004 Wiley-Liss, Inc. [source] Variable structure robust state and parameter estimatorINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 2 2001Alex S. Poznyak Abstract The problem of simultaneous robust state and parameters estimation for a class of SISO non-linear systems under mixed uncertainties (unmodelled dynamics as well as observation noises) is addressed. A non-linear variable structure robust ,observer,identifier' is introduced to obtain the corresponding estimates. Lie derivative technique is used to obtain the observability conditions for the equivalent extended non-linear system. It is shown that, in general, the extended system can lose the global observability property and a special procedure is needed to work well in this situation. The suggested adaptive observer has the non-linear high-gain observer structure with adjusted parameters that provides ,a good' upper bound for the identification error performance index. The van der Monde transformation is used to derive this bound which turns out to be tight. Three examples dealing with a simple pendulum, the Duffing equation and the van del Pol oscillator are considered to illustrate the effectiveness of the suggested approach. Copyright © 2001 John Wiley & Sons, Ltd. [source] D-Dimer test in cancer patients with suspected acute pulmonary embolismJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2005M. DI NISIO Summary.,Background:,The safety of a D-dimer (DD) measurement in cancer patients with clinically suspected pulmonary embolism (PE) is unclear. Objectives:,The aim of this study was to assess the accuracy of the DD test in consecutive patients with clinically suspected PE with and without cancer. Methods:,The diagnostic accuracy of DD (Tinaquant D-dimer) was first retrospectively assessed in an unselected group of patients referred for suspected PE (n = 350). Subsequently, the predictive value of the DD was validated in a group of consecutive inpatients and outpatients with clinically suspected PE prospectively enrolled in a management study (n = 519). The results of the DD test in cancer patients were assessed according to the final diagnosis of PE and the 3-month clinical follow-up. Results:,In the first study group, DD showed a sensitivity and a negative predictive value (NPV) of 100% and 100% in patients with cancer and 97% and 98% in those without malignancy, respectively. In the validation cohort, the sensitivity and NPV of DD were both 100% (95% CI 82%,100% and 72%,100%, respectively), whereas in patients without malignancy, the corresponding estimates were 93% (95% CI 87%,98%) and 97% (95% CI, 95%,99%), respectively. The specificity of DD was low in patients with (21%) and without cancer (53%). Conclusions:,A negative DD result safely excludes the diagnosis of PE in patients with cancer. Because of the low specificity, when testing 100 patients with suspected PE, a normal DD concentration safely excludes PE in 15 patients with cancer and in 43 patients without cancer. [source] Investigation of Gibbs sampling conditions to estimate variance components from Japanese Black carcass field dataANIMAL SCIENCE JOURNAL, Issue 5 2009Aisaku ARAKAWA ABSTRACT The genetic evaluation using the carcass field data in Japanese Black cattle has been carried out employing an animal model, implementing the restricted maximum likelihood (REML) estimation of additive genetic and residual variances. Because of rapidly increasing volumes of the official data sets and therefore larger memory spaces required, an alternative approach like the REML estimation could be useful. The purpose of this study was to investigate Gibbs sampling conditions for the single-trait variance component estimation using the carcass field data. As prior distributions, uniform and normal distributions and independent scaled inverted chi-square distributions were used for macro-environmental effects, breeding values, and the variance components, respectively. Using the data sets of different sizes, the influences of Gibbs chain length and thinning interval were investigated, after the burn-in period was determined using the coupling method. As would be expected, the chain lengths had obviously larger effects on the posterior means than those of thinning intervals. The posterior means calculated using every 10th sample from 90 000 of samples after 10 000 samples discarded as burn-in period were all considered to be reasonably comparable to the corresponding estimates by REML. [source] Genetic analysis of residual feed intakes and other performance test traits of Japanese Black cattle from revised protocolANIMAL SCIENCE JOURNAL, Issue 3 2008Takeshi OKANISHI ABSTRACT The performance test protocol for Japanese Black cattle was revised in April 2002. This resulted in restriction of access to concentrate (based on body weight) and modification of the concentrate's ingredients. Genetic parameters of growth and feed utilization traits of the performance test were estimated using 1304 records using the revised protocol. Residual feed intakes (RFIs) as alternative indicators for feed utilization efficiency were included. (Co)variance components were estimated by EM-REML. Heritabilities for growth traits were between 0.26 and 0.47. Heritabilities for feed intakes and conversions ranged from 0.25 to 0.37 and from 0.03 to 0.29, respectively. Genetic variances and heritabilities were lower for the revised protocol. Highly positive genetic correlations of daily gain (DG) with feed intakes indicated selection on DG is expected to increase feed intake. Selection on feed conversion may lead to higher DG. The heritability estimates for RFIs ranged from 0.10 to 0.33 and were generally higher than corresponding estimates for feed conversion ratios. RFI of TDN showed positive genetic correlations with all feed intakes. The reduction of feed intakes could be expected through selection on the RFI without changing body size. RFIs were considered to be alternative indicators to improve feed utilization efficiency under the new performance test. [source] The burden of coronary heart disease in M,ori: population-based estimates for 2000-02AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 4 2009Martin Tobias Abstract Objective: To estimate coronary heart disease (CHD) incidence, prevalence, survival, case fatality and mortality for M,ori, in order to support service planning and resource allocation. Methods: Incidence was defined as first occurrence of a major coronary event, i.e. the sum of first CHD hospital admissions and out-of-hospital CHD deaths in people without a hospital admission for CHD in the preceding five years. Data for the years 2000-02 were sourced from the New Zealand Health Information Service and record linkage was carried out using a unique national identifier, the national health index. Results: Compared to the non-M,ori population, M,ori had both elevated CHD incidence and higher case fatality. Median age at onset of CHD was younger for M,ori, reflecting both higher age specific risks and younger population age structure. The lifetable risk of CHD for M,ori was estimated at 37% (males) and 34% (females), only moderately higher than the corresponding estimates for the non-M,ori population, despite higher M,ori CHD incidence. This reflects the offsetting effect of the higher ,other cause' mortality experienced by M,ori. Median duration of survival with CHD was similar to that of the non-M,ori population for M,ori males but longer for M,ori females, which is most likely related to the earlier age of onset. Conclusions: This study has generated consistent estimates of CHD incidence, prevalence, survival, case fatality and mortality for M,ori in 2000-02. The inequality identified in CHD incidence calls for a renewed effort in primary prevention. The inequality in CHD case fatality calls for improvement in access for M,ori to secondary care services. [source] | |||||||||||||