Forecasting the Incidence of Cancer in Regional Victoria,Australia

Loddon Mallee Integrated Cancer Service plays a key role in planning the delivery of cancer services in the Loddon Mallee Region of Victoria, Australia. Forecasting the incidence of cancer is an important part of planning for these services. This article is written from an industry perspective. We describe the context of our work, review the literature on forecasting the incidence of cancer, discuss contemporary approaches, describe our experience with forecasting models, and list issues associated with applying these models. An extensive bibliography illustrates the world-wide interest in this forecasting problem. We hope that it is useful to researchers.     

Regression Modelling of Disease Risk in Relation to Point Sources

We describe a class of models for the investigation of possible raised risk of disease around putative sources of environmental pollution. An adaptation of the point process method suggested by Diggle and Rowlingson is presented, allowing the use of routinely available aggregated data and incorporating the more general distance–risk model suggested by Elliott and co-workers. An application to data on cancers of the stomach around municipal solid waste incinerators is presented.     

灰霾天气对人体健康的危害

灰霾是颗粒物和气体污染物导致的可察觉到的能见度降低的污染天气现象。近年来,随着城市化进程的快速发展,城市大气污染加剧,灰霾天气也随之增多。介绍了灰霾天气的形成过程、化学成分及其危害,并从流行病学等角度出发,对灰霾天气对人体健康效应的研究成果进行了综述。     

BSE Risk Assessment as a Basis for Updating French Screening Policy

The current French bovine spongiform encephalopathy (BSE) surveillance system, based on rapid testing of all cattle over 24 months of age and on clinical diagnosis, detects all clinical cases and some preclinical cases of BSE. Several indicators point to a marked shrinkage of the French BSE epidemic in recent years, owing to risk reduction measures. Meat and bone meal, the only known vector of the BSE agent, was banned in feed for all farmed species in November 2000. Thus the surveillance system may be relaxed. The objective of this risk assessment study was to provide information for decisionmakers on the minimum age at which healthy and high-risk cattle now need to be screened with rapid tests. For this purpose, we used the back-calculation method to project the course of the BSE epidemic. We examined the predicted patterns of the number and age distribution of cases of BSE that would be detected by the different existing surveillance streams. Various theoretical sensitivities of rapid tests were explored. Assuming that feed-borne sources of infection no longer exist, and that BSE does not occur spontaneously, our models suggest that it would have been possible to raise the minimum age for rapid tests to 66 months in early 2006, whereas theoretical reasoning, based on the assumption that the total meat and bone meal ban was effective in November 2001, suggests that this age cutoff could only be raised to 48 months in early 2006. These results only apply to cattle born and bred in France. If the situation remains unchanged, the age cutoff could be raised incrementally each year.     

Predictors of gambling problems among male adolescents

The study concerns prediction of gambling problems in 178 male adolescents (aged 16 and 18 years) who completed a questionnaire, which included the South Oaks Gambling Screen (SOGS), a version of the Temperament and Character Inventory and a number of questions concerning social background, emotional and life-style factors. About 27% of the boys gamble at least weekly. As many as 16% qualify as probable pathological gamblers according to the SOGS. Another 7% are at risk. None of the social background factors are related to severity of gambling problems. The only significant family factor is parental substance misuse. The optimal multivariate model predicts about 30% of the variance in gambling problems. The strongest factor is frequency of alcohol drinking. Several factors indicate a personality with problems in relations to others. Another factor indicates a dreamy personality. Unexpectedly, impulsiveness is not related to gambling. In conclusion, problem gambling among male adolescents is related to life-style and personality, especially in relation to others, but not to usual social background factors. Gamblers are asocial rather than impulsive. The nature of this finding should be further explored, since an asocial personality may point at genetics as well as to early social influences, as may the finding on the relation between gambling and parental drinking.     

Mixing patterns between age groups in social networks

We present a method for estimating transmission matrices that describe the mixing and the probability of infection between age groups. Transmission matrices can be used to estimate age-dependent forces of infection in age-structured, compartmental models for the study of infectious diseases. We analyze the social network generated by the synthetic population of Portland and extract mixing patterns. Our results show that the mixing within the population consists of two groups, children and adults. Children interact most frequently with other children close to their own age, while adults interact with a wider range of age groups and the durations of typical adult contacts are shorter than typical contacts between children. Furthermore, the transmission matrix shows that children are more likely to acquire infection than adults.     

Managing Potential Health Risks from Electric Powerlines: A Decision Analysis Caught in Controversy

Over the past 20 years, several epidemiological studies have found an association between exposure to electromagnetic fields (EMFs) and health effects, including childhood leukemia and adult brain cancer. However, experts strongly disagree about whether this association is causal and, if so, how strong it is. In this article, we examine several alternatives to reduce EMFs from sources of the California power grid, including undergrounding distribution and transmission lines and reconfiguring or rephasing lines. The alternatives were evaluated in terms of the potential health risk reduction, cost, impacts on service reliability, property values, and many other consequences. Because of the uncertainty about an EMF-health link, the main effort was to determine the sensitivity of the decisions to the probability and seriousness of an EMF hazard. User-friendly computer models were developed to allow stakeholders to change the model assumptions and parameters to analyze the impacts of their own assumptions and estimates on the decision. The analysis clearly demonstrated that only four of the many concerns raised by the stakeholders could make a difference in the decision: health risks, costs, service reliability, and property values. Whether undergrounding, moderate alternatives for EMF reduction, or no change was the best decision depended on a few key factors, including the probability that EMF exposure is a hazard, the severity of this hazard, how the EMF reduction measures are financed, and the impacts on property values. While the analysis did not resolve the EMF issues, it showed that even in the most controversial settings, a little analysis goes a long way to clarifying the issues and to focus the debate.     

A Method for Estimating Lifetime Cancer Risks from Limited Epidemiologic Data

Partly because of the poor quality of exposure information on humans, most lifetime carcinogenic risk assessments have been based on animal data. There are, however, surrogate measures for exposure that have not been fully utilized. One of these is duration of exposure where data on mean exposure levels are available. A method is presented for the use of such data, and the method is illustrated by developing a risk assessment from the available epidemiologic literature on gasoline and kidney cancer. This risk assessment is fairly consistent across studies and close to a risk assessment based upon an experiment with rats. While there needs to be much improvement in the quality of environmental data available to epidemiologists, it is possible that a number of risk assessments can be made from existing epidemiologic data and efforts directed away from extrapolation from animal data.