scholarly journals Empirical evaluation of the influence of control selection schemes on relative risk estimation: the Welsh nickel workers study.

1995 ◽  
Vol 52 (7) ◽  
pp. 489-493 ◽  
Author(s):  
A Morabia ◽  
T Ten Have ◽  
J R Landis
2016 ◽  
Vol 78 (11) ◽  
Author(s):  
Farah Kristiani ◽  
Benny Yong ◽  
Robyn Irawan

Recently, dengue as one of the most dangerous diseases in the world has attracted more attention due to its soaring infection cases. One method to estimate the relative risks of dengue transmission commonly used is through the statistics approach. Dengue cases of all severity levels spread rapidly in every district in Bandung, Indonesia every month. There are two different severity levels of dengue disease: the early-stage known as Dengue Fever (DF) and the severe-stage manifested as Dengue Hemorrhagic Fever (DHF) and Dengue Shock Syndrome (DSS). This research investigates the early stage, the severe stage, and the combination of both stages. The non-spatial Poisson-gamma model and spatial Besag, York, and Mollie (BYM) model are applied to estimate the relative risks in each district in Bandung every month. These two models are chosen to analyze whether there is a spatial effect in dengue transmission in particular critical area. This research will use 2013’s data from St. Borromeus hospital, one of the reputable hospitals in Bandung. The results show that the implementation of non-spatial Poisson-gamma and spatial BYM models does not depict a significant difference in the result of the relative risk estimation of dengue transmission in Bandung. The Deviance Information Criterion (DIC) diagnostic indicates that non-spatial model is better than the spatial model.  Therefore, it can be concluded that there is no spatial effect in dengue transmission in Bandung. It means that dengue transmission in Bandung is not affected by neighboring areas. This analysis is also applicable to every stage estimated, both for the early-stage as well as the severe-stage.  


2019 ◽  
Vol 1366 ◽  
pp. 012118
Author(s):  
Sufi Hafawati Ideris ◽  
Muhammad Rozi Malim ◽  
Norshahida Shaadan

2019 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiaoxiao Song ◽  
Yan Li ◽  
Le Cai ◽  
Wei Liu ◽  
Wenlong Cui

ObjectiveThe purpose is to propose a serial of approach for estimation for disease risk for ILI in "small area" and present the risk values by spatio-temporal disease mapping or an interactive visualization with HTML format.IntroductionDisease mapping is a method used to descript the geographical variation in risk (heterogeneity of risk) and to provide the potential reason (factors or confounders) to explain the distribution. Possibly the most famous uses of disease mapping in epidemiology were the studies by John Snow of the cholera epidemics in London. Accurate estimation relative risk of small areas such as mortality and morbidity, by different age, ethnic group, interval and regions, is important for government agencies to identify hazards and mitigate disease burden. Recently, as the innovative algorithms and the available software, more and more disease risk index has been pouring out. This abstract will provide several estimation risk index, from raw incidence to model-based relative risks, and use visual approach to display them.MethodsAll the data are from a syndromic surveillance and real-time early warning system in the Yunnan province in the China. For brief introduction aim, we are using the ILI (Influenza-like illness) data in December 2017 in one county. The relative risks of disease in small area are including: raw incidence, a standardized morbidity ratio (SMR), Empirical Bayes smoothing estimation relative risk (EB-RR) and the Besag-York-Mollio model (BYM). The incidence in each small area is common used for descriptive the risk but fail to comparable directly since the different population at risk in each area. SMR is a good way to deal with this incomparability. But SMR can give rise to imprecisely estimate in areas with small populations. Empirical Bayes estimation approach has been used for smoothing purpose and can be seen as a compromise between relative risks and P-values. However, all above approaches are inept to have spatial or spatio-temporal structure in mind. BYM based the Bayesian inference can handle both the area-specific spatial structured component (such as intrinsic conditional autoregressive component) and the exchangeable random effect (unstructured component). All the analyses are implemented in the R software with INLA package (http://www.r-inla.org). The outcome of relative risk estimation with visual way and interactive maps showing are using ggplot2 and leaflet packages.Results1, the spatio-temporal raw cases of ILI from 2017/12/01 to 2017/12/31 is Fig.12. the SMR and EB-RR estimation RR of ILI are in Fig.2 and Fig.33. the most excited is the interactive visualization with HTML format for all the risk indexes is visited http://rpubs.com/ynsxx/424814 in detail. And the screenshot is Fig.4ConclusionsSmall area disease risk estimation is important for disease prevention and control. The faster function of computer with power R software can lead to advance in disease mapping, allowing for complex spatio-temporal models and communicate the results with visualization way. 


Author(s):  
Ian Graham ◽  
Therese Cooney ◽  
Dirk De Bacquer

Cardiovascular disease (CVD) is the biggest cause of death worldwide. The underlying atherosclerosis starts in childhood and is often advanced when it becomes clinically apparent many years later. CVD is manageable: in countries where it has reduced this is due to changes in lifestyle and risk factors and to therapy. Risk factor management reduces mortality and morbidity. In apparently healthy people CVD risk is most frequently the result of multiple interacting risk factors and a risk estimation system such as SCORE can assist in making logical management decisions. In younger people a low absolute risk may conceal a very high relative risk, and use of the relative risk chart or calculation of their ‘risk age’ may help in advising them of the need for intensive life style efforts. All risk estimation systems are relatively crude and require attention to qualifying statements.


2021 ◽  
Vol 29 (2) ◽  
Author(s):  
Sufi Hafawati Ideris ◽  
Muhammad Rozi Malim ◽  
Norshahida Shaadan

The disease leptospirosis is known to be endemic in Malaysia, and it significantly impacts human wellbeing and the national economy. Current surveillance systems are based on morbidity and mortality leptospirosis national data from the Ministry of Health and remain inadequate due to the number of unreported and misdiagnosed cases. A robust surveillance system is needed to monitor temporal and spatial changes which yield improvements in terms of identifying high-risk areas and disease behaviour. The objective of this study is to identify high-risk areas by estimating relative risk using existing models which are the Standardized Morbidity Ratio (SMR), Poisson-gamma, log-normal, Besag, York and Mollié (BYM) and mixture models. An alternative model is also proposed which involves transmission systems and stochastic elements, namely the stochastic Susceptible-Infected-Removed (SIR) transmission model. This estimation of risk is expected to assist in the early detection of high-risk areas which can be applied as a strategy for preventive and control measures. The methodology in this paper applies relative risk estimates to determine the infection risk for all states in Malaysia based on monthly data from 2011 to 2018 using WinBUGS 1.4 software. The results of relative risks are discussed and presented in tables and graphs for each model to disclose high-risk areas across the country. Based on the risk estimates, different models used have different risk interpretations and drawbacks which make each model different in its use depending on the objectives of the study. As a result, the deviance information criteria (DIC) values obtained do not differ greatly from each expected risk which was estimated


Sign in / Sign up

Export Citation Format

Share Document