Journal of cancer epidemiology and prevention最新文献

{"title":"Transmission/disequilibrium test when neither parent is available in some families: a non-iterative approach.","authors":"W C Lee","doi":"10.1080/147666502321082755","DOIUrl":"https://doi.org/10.1080/147666502321082755","url":null,"abstract":"<p><strong>Background: </strong>The transmission/disequilibrium test (TDT) is a simple method of detecting linkage between a marker locus and a disease-susceptibility locus. The test requires genotype data from the affected individuals (the probands) and their parents, the 'case-parents triads'. However, missing data from parents often complicate the situations. Several non-iterative methods, such as the sibling-based TDT, the reconstruction-combined TDT, and the 1-TDT have been proposed to deal with the problem. But when the father, the mother, and other non-proband siblings in a family are all unavailable for study, that family has to be excluded from analysis by any of the above methods.</p><p><strong>Methods: </strong>The author proposes a new non-iterative method to deal with the situation when the data contain some 'orphaned' probands. The method utilises the complete data from case-parents triads to infer probabilistically the missing parental genotypes, under the assumption that the missingness is independent of genotype and ethnic origin. The methods can be tailored to specific genetic models, such as the gene-dose, dominance, and recessive alternatives.</p><p><strong>Results: </strong>Simulation analysis shows that, under the null hypothesis of no linkage, the proposed method is not prone to produce an excess of false positive results, even in complex situations such as population stratification or assortive mating. Under the linkage alternative, the new method recaptures much of the information that would be lost by discarding the orphaned probands.</p><p><strong>Discussion: </strong>The method provides a way for dealing with the situation where neither parents nor siblings are available in a TDT study.</p>","PeriodicalId":84981,"journal":{"name":"Journal of cancer epidemiology and prevention","volume":"7 2","pages":"97-103"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22173601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"UK bovine carcass meat consumed as burgers, sausages and other meat products: by birth cohort and gender.","authors":"J D Cooper,&nbsp;S M Bird","doi":"10.1080/147666502321082719","DOIUrl":"https://doi.org/10.1080/147666502321082719","url":null,"abstract":"<p><strong>Background: </strong>The most likely human exposure to bovine spongiform encephalopathy (BSE) is dietary, through beef mechanically recovered meat (MRM) and head meat used in burgers, sausages and other meat products. The majority, reportedly 90% of beef MRM and 80% of head meat, was used in burgers. To enable quantification of UK dietary exposure to BSE, we quantified bovine carcass meat consumed as burgers, sausages and other meat products by birth cohort, gender and calendar period (1980-1989, 1990-1996).</p><p><strong>Methods: </strong>Synthesis of dietary data (cross-sectional National Dietary and Nutrition Surveys, and serial National Food Surveys and Realeat Surveys) to simulate weekly consumption by one-thousandth of the UK population in each year from 1980 to 1996.</p><p><strong>Findings: </strong>In 1980-1989, the highest number of consumers (per 7 days) of all three food groups was in the 1940-1969 birth cohort - averaging 3.7 million male consumers of burgers, 2.6 million of sausages and 8.5 million of other meat products. The post-1969 birth cohort had the next highest number of consumers of burgers (1.8 million males). In 1990-1996, consumer numbers declined for the two older cohorts, most strikingly for burgers (down to 2.5 million males in the 1940-1969 cohort). The 1940-1969 cohort retained the highest number of consumers of sausages and other meat products, and second place for burgers. Male consumption was higher, even in the pre-1940 birth cohort where, for demographic reasons, female consumers outnumbered males. In the post-1969 birth cohort, female consumption of bovine carcass meat weight as burgers increased from 68 tonnes in 1980-1989 to 81 tonnes in 1990-1996, and male consumption increased more markedly (by 41%) from 84 tonnes to 119 tonnes; and similarly for other meat products.</p><p><strong>Interpretation: </strong>Properly marshalled age-group and gender-specific consumption data contribute to a clearer understanding of the demography of those who were at risk of dietary exposure to BSE and of when their exposure intensity was greatest. Other countries may need to consider using dietary data to model their human BSE exposure from UK and other BSE-affected regions.</p>","PeriodicalId":84981,"journal":{"name":"Journal of cancer epidemiology and prevention","volume":"7 2","pages":"49-57"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22173597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Avoidance of premature death: a new definition for the proportion cured.","authors":"P D Sasieni,&nbsp;J Adams,&nbsp;J Cuzick","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>For many cancers, five-year survival is used as a synonym for cure. For some sites, such as breast, this is inappropriate since there is still considerable excess mortality 5-15 years following diagnosis. We propose using the probability of not dying prematurely as a surrogate for the probability of being cured. This is estimated without the need for information on the cause of death by comparing all-cause-mortality rates in patients with cancer to those in the general population. We also consider the probability of 'cure' in those who have survived a certain number of years since diagnosis. These quantities are estimated for various cancer sites using SEER data. The proportion not dying prematurely varies considerably for common cancers from 12% for lung cancer to 84% for prostate cancer. In women, the percentage 'cured' for colon and breast cancer are very similar at 56% and 58% respectively, but in those who survive 5 years, they are quite different--91% and 78% respectively. The proposed statistic is useful. For diseases in which excess mortality is primarily within five years of diagnosis, it agrees well with 5-year relative survival. Interpretation of differences between countries or over time is complicated and requires consideration of incidence and mortality data.</p>","PeriodicalId":84981,"journal":{"name":"Journal of cancer epidemiology and prevention","volume":"7 4","pages":"165-71"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22471455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Parametric mixture model for analysing relative survival of patients with multiple cancers.","authors":"S Heinävaara,&nbsp;T Hakulinen","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Background: </strong>This study aimed to provide a parametric mixture model for analysing relative survival and cure rates of patients with multiple cancers.</p><p><strong>Methods: </strong>A new model was introduced by extending a parametric mixture model on relative survival of patients with a single cancer. The model was applied to empirical data on lung cancer as a first and second tumour after a first localised colorectal cancer.</p><p><strong>Results: </strong>Survival and cure from subsequent cancer are estimatable with the parametric mixture model on relative survival of patients with multiple cancers. Survival from lung cancer does not differ between the first and second tumour, but there is suggestive evidence that survival from second lung cancer is higher than that from the first lung cancer.</p><p><strong>Discussion: </strong>Relative survival analysis of patients with multiple cancers can be extended to incorporate cure rates and excess hazards related to the individual cancers. Prognostic factors can be included in the model.</p>","PeriodicalId":84981,"journal":{"name":"Journal of cancer epidemiology and prevention","volume":"7 3","pages":"147-53"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22314653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Angular regression and the detection of the seasonal onset of disease.","authors":"F. Gao, S. K. Seah, P. Foster, K. Chia, D. Machin","doi":"10.1080/14766650252962658","DOIUrl":"https://doi.org/10.1080/14766650252962658","url":null,"abstract":"BACKGROUND In examining the seasonality of onset of a disease over the year, investigators attempt to identify the peak of onset, and its magnitude. A second objective is to see if the day in which the disease manifests itself is related to subject-specific characteristics or environmental factors. METHOD This paper describes appropriate statistical methodology for the situation where seasonality can be summarised by either a single peak or several peaks, possibly determined by patient characteristics or external influences. The circular, rather than linear, nature of the day of onset of a disease (irrespective of year) requires angular regression techniques to assess these relations, and the von Mises distribution replaces the normal distribution in this context. RESULTS The methods outlined are illustrated by a national study of those experiencing an attack of acute primary angle-closure glaucoma in Singapore. CONCLUSIONS We recommend re-analyses of already published work on seasonality of disease using this angular methodology. We anticipate that this may provide both useful further insight into aspects of aetiology and case studies for the methods themselves.","PeriodicalId":84981,"journal":{"name":"Journal of cancer epidemiology and prevention","volume":"7 1 1","pages":"29-35"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59961089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A capture-recapture model to estimate prevalence of children born in Scotland with developmental eye defects.","authors":"H Campbell,&nbsp;E Holmes,&nbsp;S MacDonald,&nbsp;D Morrison,&nbsp;I Jones","doi":"10.1080/14766650252962649","DOIUrl":"https://doi.org/10.1080/14766650252962649","url":null,"abstract":"<p><strong>Background: </strong>Microphthalmia, anophthalmia and coloboma (MAC) are closely related structural developmental eye defects that have caused public concern in the UK following media reports of apparent clusters of cases. An extensive search was carried out to identify potential cases, and diagnoses were confirmed by ophthalmological review. Despite this effort, it was recognised that some cases would remain unidentified. Capture-recapture methods could improve the accuracy of the study's birth prevalence estimate.</p><p><strong>Methods: </strong>A register of all children born with the developmental eye defects of MAC in Scotland (1981-96) was compiled. This identified 188 cases from eight national ascertainment sources. The methods described by Hook and Regal were used to determine possible estimates for each source. A log-linear method of capture-recapture was used to fit a model to the number of children identified by the different combinations of the eight national sources, and the individual sources were included in the model as main effects.</p><p><strong>Results: </strong>Maximum-likelihood estimates were calculated for tables of captured/not captured by one source versus any other source. The estimated number of unobserved cases for the most complete source, the register of congenital anomalies for Scotland, and the seven others combined is 78 (95% CI 53-115). Estimates calculated from two different log-linear models of the numbers of cases unobserved by all sources were 61 (95% CI 43-86) and 175 (95% CI 106-287). An external check with an independent congenital-anomalies register in one region, which is known to have high completeness, gave an estimate of 120. The study found a birth prevalence of MAC in Scotland of 1.9/10000, based on total live births during the study period. The capture-recapture analysis suggests that the true birth prevalence lies between 2.4/10 000 and 3.5/10000.</p><p><strong>Discussion: </strong>Our experience shows that, even with multiple sources of ascertainment and considerable resources directed at case identification, a considerable level of under-ascertainment of congenital eye-anomalies still results, and suggests that the use of capture-recapture analysis would be a useful addition to congenital anomalies registers for needs assessment, disease-burden estimates and health-service planning.</p>","PeriodicalId":84981,"journal":{"name":"Journal of cancer epidemiology and prevention","volume":"7 1","pages":"21-8"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"22056726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}