Pub Date : 2001-01-01DOI: 10.1080/13595220152601837
Emily Banks, Valerie Beral, Rebecca Cameron, A. Hogg, N. Langley, I. Barnes, D. Bull, J. Elliman, C. Harris
BACKGROUND Epidemiological studies of the effects of hormone replacement therapy (HRT) often rely on exposure data and information on past health from self-administered questionnaires. The accuracy with which women report current use of HRT and the specific preparation in use is not known. This study aims to compare aspects of self-reported use of HRT and treatment for various conditions with data from general practice prescription records. METHODS Reported questionnaire data on use of HRT were compared with those on the general practice prescription record for 570 women participating in the Million Women Study from two general practices in the UK. RESULTS There was excellent agreement between data from the self-administered questionnaire and the prescription record: 96% agreement (kappa = 0.91) for current use of HRT, 95% agreement (kappa = 0.90) for any use of HRT during the period covered by the prescription record, and 97% agreement (kappa = 0.95) among current users for whether the HRT preparation contained oestrogen alone, combined oestrogen/progestogen, or some other constituents. Among former HRT users who provided questionnaire information on the preparation they used most recently, there was 69% agreement on the proprietary preparation used and 97% agreement (kappa = 0.93) on the hormonal constituents used. Agreement between reported treatment for various conditions and the presence of a prescription appropriate for that condition ranged from 89-99% (kappa 0.53-0.92), and was highest for thyroid disease and asthma. CONCLUSION Important aspects of use of HRT, such as type of preparation currently being used, are reported very reliably by women completing a self-administered questionnaire.
{"title":"Agreement between general practice prescription data and self-reported use of hormone replacement therapy and treatment for various illnesses.","authors":"Emily Banks, Valerie Beral, Rebecca Cameron, A. Hogg, N. Langley, I. Barnes, D. Bull, J. Elliman, C. Harris","doi":"10.1080/13595220152601837","DOIUrl":"https://doi.org/10.1080/13595220152601837","url":null,"abstract":"BACKGROUND Epidemiological studies of the effects of hormone replacement therapy (HRT) often rely on exposure data and information on past health from self-administered questionnaires. The accuracy with which women report current use of HRT and the specific preparation in use is not known. This study aims to compare aspects of self-reported use of HRT and treatment for various conditions with data from general practice prescription records. METHODS Reported questionnaire data on use of HRT were compared with those on the general practice prescription record for 570 women participating in the Million Women Study from two general practices in the UK. RESULTS There was excellent agreement between data from the self-administered questionnaire and the prescription record: 96% agreement (kappa = 0.91) for current use of HRT, 95% agreement (kappa = 0.90) for any use of HRT during the period covered by the prescription record, and 97% agreement (kappa = 0.95) among current users for whether the HRT preparation contained oestrogen alone, combined oestrogen/progestogen, or some other constituents. Among former HRT users who provided questionnaire information on the preparation they used most recently, there was 69% agreement on the proprietary preparation used and 97% agreement (kappa = 0.93) on the hormonal constituents used. Agreement between reported treatment for various conditions and the presence of a prescription appropriate for that condition ranged from 89-99% (kappa 0.53-0.92), and was highest for thyroid disease and asthma. CONCLUSION Important aspects of use of HRT, such as type of preparation currently being used, are reported very reliably by women completing a self-administered questionnaire.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59835767","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}
Pub Date : 2001-01-01DOI: 10.1080/13595220152601792
Virtanen Ji
BACKGROUND Several factors are claimed to have contributed to the decline in dental caries that has occurred over recent decades in many industrialised countries. METHODS A retrospective cohort design follow-up study of trends in dental caries in three age cohorts born a decade apart is reported from Finland. Subjects born in the 1960s, 1970s and 1980s (n = 1275) were monitored annually through their patient records, and changes in the distribution, extent and rate of caries attack (caries leading to restorations or extractions) were analysed. Logistic and Poisson regression techniques were employed to detect trends and Kaplan-Meier survival methods were used for the rate analyses. RESULTS A marked decrease in caries was observed and the proportion of disease-free subjects increased gradually towards the younger cohorts. Logistic regression analysis showed clear trends, in that the odds ratios (ORs) for the cohort effect were 8.93 [95% confidence interval (CI) = 7.95-10.04] and 4.32 (95% CI = 3.92-4.75) in the 1960 and 1970 cohorts, respectively, relative to the 1980 cohort, and that for the age (year) effect was 1.44 (95% CI = 1.42-1.46). Similar types of cohort and age effects (p < 0.0001) were found in the disease progression analyses. The rate analyses showed statistically highly significant differences between the three cohorts (p < 0.001) for both sexes. The caries decline was a lasting one, in spite of the delay in restorations observed in the youngest cohort. DISCUSSION The results indicate a vast and continuous trend in the incidence of dental caries leading to restorations and extractions. Significant changes in the rate and extent of disease progression have taken place, which will inevitably affect the future public health agenda.
近几十年来，在许多工业化国家，有几个因素导致了龋齿的减少。方法回顾性队列设计，对芬兰三个年龄队列中出生间隔十年的龋齿趋势进行随访研究。通过患者记录对出生在1960、1970和1980年代的受试者(n = 1275)进行年度监测，分析龋病发作(导致修复或拔牙的龋病)的分布、程度和发生率的变化。采用Logistic和泊松回归技术检测趋势，采用Kaplan-Meier生存法进行发生率分析。结果龋病发生率明显下降，无龋患者比例逐渐向年轻化方向增加。Logistic回归分析显示出明显的趋势，1960年和1970年队列效应的比值比(ORs)分别为8.93[95%可信区间(CI) = 7.95-10.04]和4.32 (95% CI = 3.92-4.75)，与1980年队列相比，年龄(年份)效应的比值比为1.44 (95% CI = 1.42-1.46)。在疾病进展分析中发现了相似类型的队列效应和年龄效应(p < 0.0001)。比率分析显示，在三个队列中，男女之间的统计学差异非常显著(p < 0.001)。龋齿的下降是持久的，尽管在最年轻的队列中观察到龋齿的修复延迟。研究结果表明，龋病的发生率有一个巨大而持续的趋势，导致修复和拔牙。疾病进展的速度和程度发生了重大变化，这将不可避免地影响到未来的公共卫生议程。
{"title":"Changes and trends in attack distributions and progression of dental caries in three age cohorts in Finland.","authors":"Virtanen Ji","doi":"10.1080/13595220152601792","DOIUrl":"https://doi.org/10.1080/13595220152601792","url":null,"abstract":"BACKGROUND Several factors are claimed to have contributed to the decline in dental caries that has occurred over recent decades in many industrialised countries. METHODS A retrospective cohort design follow-up study of trends in dental caries in three age cohorts born a decade apart is reported from Finland. Subjects born in the 1960s, 1970s and 1980s (n = 1275) were monitored annually through their patient records, and changes in the distribution, extent and rate of caries attack (caries leading to restorations or extractions) were analysed. Logistic and Poisson regression techniques were employed to detect trends and Kaplan-Meier survival methods were used for the rate analyses. RESULTS A marked decrease in caries was observed and the proportion of disease-free subjects increased gradually towards the younger cohorts. Logistic regression analysis showed clear trends, in that the odds ratios (ORs) for the cohort effect were 8.93 [95% confidence interval (CI) = 7.95-10.04] and 4.32 (95% CI = 3.92-4.75) in the 1960 and 1970 cohorts, respectively, relative to the 1980 cohort, and that for the age (year) effect was 1.44 (95% CI = 1.42-1.46). Similar types of cohort and age effects (p < 0.0001) were found in the disease progression analyses. The rate analyses showed statistically highly significant differences between the three cohorts (p < 0.001) for both sexes. The caries decline was a lasting one, in spite of the delay in restorations observed in the youngest cohort. DISCUSSION The results indicate a vast and continuous trend in the incidence of dental caries leading to restorations and extractions. Significant changes in the rate and extent of disease progression have taken place, which will inevitably affect the future public health agenda.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59835809","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}
Pub Date : 2001-01-01DOI: 10.1080/13595220152601800
J. Cui, J. Hopper
BACKGROUND This paper aims to determine the family history distribution of a particular disease as a result of its specific genetic aetiology, defined by the mode of inheritance (dominant or recessive), allele frequency, and increased risk in carriers of the genetic risk (genetic relative hazard). Here, 'family history' is the number of affected first-degree relatives of a defined index person (termed the proband), who may be either affected or unaffected with the disease in question. METHODS We consider model parameters relevant for female breast cancer in Australia. Breast cancer affects one sex only, although the extension of the model to both sexes is straightforward. RESULTS Contour plots of the relationships between family history distribution and genetic parameters, for both dominant and recessive inheritance, are displayed for the proband being either affected or unaffected. CONCLUSIONS Under dominant inheritance and an allele frequency of 0.005 (as may be appropriate for mutations in the genes BRCA1 and BRCA2), the proportion of affected probands diagnosed with breast cancer before age 50 years and who have no family history is stable as the genetic relative hazard increases from 5 to 20, decreasing from 89% to 85%. The probability that a proband has a family history is higher when the proband is affected compared with when she is not. For allele frequency 0.005 and relative hazard 10, the ratio of the probability of i (i = 1, 2, 3 or more) affected relatives for an affected proband compared with an unaffected proband is 1.2, 2 and 4.5 respectively, under dominant inheritance. Under recessive inheritance with allele frequency 0.35 and relative hazard 3 (as may be the case for a common polymorphism in the CYP17 gene), the corresponding ratios are 1.1, 1.3 and 1.5, respectively.
背景:本文旨在确定一种特定疾病的家族史分布，这是由于其特定的遗传病因，由遗传模式(显性或隐性)、等位基因频率和遗传风险携带者的风险增加(遗传相对危险度)来定义。在这里，“家族史”是指一个确定的指标人(称为先证者)的一级亲属的患病人数，这些人可能患有或未患该疾病。方法我们考虑与澳大利亚女性乳腺癌相关的模型参数。乳腺癌只影响一种性别，尽管将该模型扩展到两性是很简单的。结果显示了受影响或未受影响先证者的显性遗传和隐性遗传的家族史分布与遗传参数的关系线图。结论在显性遗传和等位基因频率为0.005(可能适用于BRCA1和BRCA2基因突变)的情况下，50岁前诊断为乳腺癌且无家族史的受影响先显子比例稳定，遗传相对危险度从5%增加到20%，从89%下降到85%。先证者有家族史的可能性，当先证者受到影响时比没有受到影响时要高。当等位基因频率为0.005，相对危险度为10时，在显性遗传条件下，患病先证者与未患病先证者分别有i (i = 1,2,3或更多)个患病亲属的概率之比分别为1.2、2和4.5。在等位基因频率为0.35、相对危险度为3的隐性遗传情况下(如CYP17基因的常见多态性)，相应的比值分别为1.1、1.3和1.5。
{"title":"Distribution of family history of a disease as a function of mode of inheritance, genetic relative hazard, allele frequency and disease status of the proband, with application to female breast cancer.","authors":"J. Cui, J. Hopper","doi":"10.1080/13595220152601800","DOIUrl":"https://doi.org/10.1080/13595220152601800","url":null,"abstract":"BACKGROUND This paper aims to determine the family history distribution of a particular disease as a result of its specific genetic aetiology, defined by the mode of inheritance (dominant or recessive), allele frequency, and increased risk in carriers of the genetic risk (genetic relative hazard). Here, 'family history' is the number of affected first-degree relatives of a defined index person (termed the proband), who may be either affected or unaffected with the disease in question. METHODS We consider model parameters relevant for female breast cancer in Australia. Breast cancer affects one sex only, although the extension of the model to both sexes is straightforward. RESULTS Contour plots of the relationships between family history distribution and genetic parameters, for both dominant and recessive inheritance, are displayed for the proband being either affected or unaffected. CONCLUSIONS Under dominant inheritance and an allele frequency of 0.005 (as may be appropriate for mutations in the genes BRCA1 and BRCA2), the proportion of affected probands diagnosed with breast cancer before age 50 years and who have no family history is stable as the genetic relative hazard increases from 5 to 20, decreasing from 89% to 85%. The probability that a proband has a family history is higher when the proband is affected compared with when she is not. For allele frequency 0.005 and relative hazard 10, the ratio of the probability of i (i = 1, 2, 3 or more) affected relatives for an affected proband compared with an unaffected proband is 1.2, 2 and 4.5 respectively, under dominant inheritance. Under recessive inheritance with allele frequency 0.35 and relative hazard 3 (as may be the case for a common polymorphism in the CYP17 gene), the corresponding ratios are 1.1, 1.3 and 1.5, respectively.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59835938","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}
Pub Date : 2001-01-01DOI: 10.1080/135952201753172999
J. Zielinski, R. Kodell, D. Krewski
BACKGROUND Exposure to two or more carcinogens may result in interactive effects in which the joint effect may be greater or less than that expected to arise as the sum of the effects of the two agents alone. In this article, we investigate the joint effects of exposure to two carcinogens within the context of the two-stage clonal expansion model of carcinogenesis. METHODS Different measures of interaction are considered based on the notions of response and dose additivity, and an index of synergy S due to Thomas (1982) used to broadly characterise the effects of joint exposure. RESULTS Interactive effects based on the index S were found to be qualitatively similar, regardless of whether cancer risk was defined in terms of age-specific relative risk, or the cumulative probability of cancer occurrence at the same age. For joint exposure to two initiators or to two completers (affecting the first or second mutation rate in the two-mutation model, respectively), S assumed values near zero, reflecting an additive relative-risk relationship. For joint exposure to two promoters (which increase the rate of proliferation of initiated cells that have sustained the first mutation), the relative-risk relationship was found to range from supramultiplicative (S > 1) in younger age groups, to subadditive (S < 0) in older ages. Other combinations of carcinogens involving promotion also displayed a broad range of interaction effects. CONCLUSIONS These results differ markedly from those reported previously by Kodell et al. (1991) for an approximate form of the two-stage model, which predicts much higher values of the index of synergy S than the exact form of the model when promotion is involved.
{"title":"Interaction between two carcinogens in the two-stage clonal expansion model of carcinogenesis.","authors":"J. Zielinski, R. Kodell, D. Krewski","doi":"10.1080/135952201753172999","DOIUrl":"https://doi.org/10.1080/135952201753172999","url":null,"abstract":"BACKGROUND Exposure to two or more carcinogens may result in interactive effects in which the joint effect may be greater or less than that expected to arise as the sum of the effects of the two agents alone. In this article, we investigate the joint effects of exposure to two carcinogens within the context of the two-stage clonal expansion model of carcinogenesis. METHODS Different measures of interaction are considered based on the notions of response and dose additivity, and an index of synergy S due to Thomas (1982) used to broadly characterise the effects of joint exposure. RESULTS Interactive effects based on the index S were found to be qualitatively similar, regardless of whether cancer risk was defined in terms of age-specific relative risk, or the cumulative probability of cancer occurrence at the same age. For joint exposure to two initiators or to two completers (affecting the first or second mutation rate in the two-mutation model, respectively), S assumed values near zero, reflecting an additive relative-risk relationship. For joint exposure to two promoters (which increase the rate of proliferation of initiated cells that have sustained the first mutation), the relative-risk relationship was found to range from supramultiplicative (S > 1) in younger age groups, to subadditive (S < 0) in older ages. Other combinations of carcinogens involving promotion also displayed a broad range of interaction effects. CONCLUSIONS These results differ markedly from those reported previously by Kodell et al. (1991) for an approximate form of the two-stage model, which predicts much higher values of the index of synergy S than the exact form of the model when promotion is involved.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59836318","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}
Pub Date : 2001-01-01DOI: 10.1080/135952201753336979
J. Kjaergaard, I. Clemmensen, H. Storm
BACKGROUND The increasing tendency to acquire data by linkage to registries not designed for research has introduced a problem into epidemiological research. The data is often crude or possibly incomplete and, in some cases, it has been proposed to use these registries in the routine acquisition of data for existing epidemiological research registries. This study estimates the validity and completeness of the registration of surgically treated malignant gynaecological diseases in the Danish National Hospital Registry 1977-88. METHODS Completeness was estimated by the method of independent case ascertainment, by comparison with the registration of surgically treated gynaecological cancer cases registered in the Danish Cancer Registry. The validity of the diagnoses was analysed by comparison with the recoding of discharge summaries describing the admission of a 5% random sample. RESULTS The completeness of registration was 87% overall. Ovarian cancer, cervical cancer and cancer of the uterus were registered with a positive predictive value (PPV) of 89-90%. DISCUSSION The results of the study emphasise the need to consider the validation of Danish Hospital Registry data before linkage and analysis. In epidemiological cancer research the Danish Cancer Registry is the better alternative when information on malignant tumours is needed.
{"title":"Validity and completeness of registration of surgically treated malignant gynaecological diseases in the Danish National Hospital Registry.","authors":"J. Kjaergaard, I. Clemmensen, H. Storm","doi":"10.1080/135952201753336979","DOIUrl":"https://doi.org/10.1080/135952201753336979","url":null,"abstract":"BACKGROUND The increasing tendency to acquire data by linkage to registries not designed for research has introduced a problem into epidemiological research. The data is often crude or possibly incomplete and, in some cases, it has been proposed to use these registries in the routine acquisition of data for existing epidemiological research registries. This study estimates the validity and completeness of the registration of surgically treated malignant gynaecological diseases in the Danish National Hospital Registry 1977-88. METHODS Completeness was estimated by the method of independent case ascertainment, by comparison with the registration of surgically treated gynaecological cancer cases registered in the Danish Cancer Registry. The validity of the diagnoses was analysed by comparison with the recoding of discharge summaries describing the admission of a 5% random sample. RESULTS The completeness of registration was 87% overall. Ovarian cancer, cervical cancer and cancer of the uterus were registered with a positive predictive value (PPV) of 89-90%. DISCUSSION The results of the study emphasise the need to consider the validation of Danish Hospital Registry data before linkage and analysis. In epidemiological cancer research the Danish Cancer Registry is the better alternative when information on malignant tumours is needed.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59836448","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}
Pub Date : 2001-01-01DOI: 10.1080/135952201753337086
J. Mackay, C. Rogers, H. Fielder, R. Blamey, D. Macmillan, C. Boggis, J. Brown, P. Pharoah, S. Moss, N. Day, J. Myles, J. Austoker, J. Gray, J. Cuzick, S. Duffy
BACKGROUND Preliminary retrospective data suggest it is possible to identify impalpable breast cancer in women presenting with a family history of breast cancer under the age of 50, by using regular mammography. In consequence, this service is offered in a number of centres in the UK. The effectiveness of such a service, however, has not been fully evaluated. METHODS We propose to perform such an evaluation in a cohort of 20000 women under the age of 50 with a significant family history of breast cancer, given regular mammographic surveillance over 5 years. Comparison of surgical and pathological data with completed and ongoing population screening trials using analysis techniques of varying complexity will be performed to obtain an accurate prediction of future breast-cancer mortality reduction. The formal aims are: i) to estimate the difference in breast-cancer mortality in women under the age of 50 with a significant family history of breast cancer having regular mammography, compared with those not being screened; ii) to estimate the cost-effectiveness of regular mammography in this group of women, compared with no screening. The increase in health service resource use attributable to such a policy will be compared with no screening, and costed. Incremental cost-effectiveness ratios of implementing the standardised mammography strategy compared with no screening will be presented in terms of the additional cost per cancer detected, per life saved and per life-year saved.
{"title":"Development of a protocol for evaluation of mammographic surveillance services in women under 50 with a family history of breast cancer.","authors":"J. Mackay, C. Rogers, H. Fielder, R. Blamey, D. Macmillan, C. Boggis, J. Brown, P. Pharoah, S. Moss, N. Day, J. Myles, J. Austoker, J. Gray, J. Cuzick, S. Duffy","doi":"10.1080/135952201753337086","DOIUrl":"https://doi.org/10.1080/135952201753337086","url":null,"abstract":"BACKGROUND Preliminary retrospective data suggest it is possible to identify impalpable breast cancer in women presenting with a family history of breast cancer under the age of 50, by using regular mammography. In consequence, this service is offered in a number of centres in the UK. The effectiveness of such a service, however, has not been fully evaluated. METHODS We propose to perform such an evaluation in a cohort of 20000 women under the age of 50 with a significant family history of breast cancer, given regular mammographic surveillance over 5 years. Comparison of surgical and pathological data with completed and ongoing population screening trials using analysis techniques of varying complexity will be performed to obtain an accurate prediction of future breast-cancer mortality reduction. The formal aims are: i) to estimate the difference in breast-cancer mortality in women under the age of 50 with a significant family history of breast cancer having regular mammography, compared with those not being screened; ii) to estimate the cost-effectiveness of regular mammography in this group of women, compared with no screening. The increase in health service resource use attributable to such a policy will be compared with no screening, and costed. Incremental cost-effectiveness ratios of implementing the standardised mammography strategy compared with no screening will be presented in terms of the additional cost per cancer detected, per life saved and per life-year saved.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59837087","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}
Pub Date : 2001-01-01DOI: 10.1080/135952201317225462
B. Erbas, Rob J Hyndman
BACKGROUND Data visualisation has become an integral part of statistical modelling. METHODS We present visualisation methods for preliminary exploration of time-series data, and graphical diagnostic methods for modelling relationships between time-series data in medicine. We use exploratory graphical methods to better understand the relationship between a time-series reponse and a number of potential covariates. Graphical methods are also used to examine any remaining information in the residuals from these models. RESULTS We applied exploratory graphical methods to a time-series data set consisting of daily counts of hospital admissions for asthma, and pollution and climatic variables. We provide an overview of the most recent and widely applicable data-visualisation methods for portraying and analysing epidemiological time series. DISCUSSION Exploratory graphical analysis allows insight into the underlying structure of observations in a data set, and graphical methods for diagnostic purposes after model-fitting provide insight into the fitted model and its inadequacies.
{"title":"Data visualisation for time series in environmental epidemiology.","authors":"B. Erbas, Rob J Hyndman","doi":"10.1080/135952201317225462","DOIUrl":"https://doi.org/10.1080/135952201317225462","url":null,"abstract":"BACKGROUND Data visualisation has become an integral part of statistical modelling. METHODS We present visualisation methods for preliminary exploration of time-series data, and graphical diagnostic methods for modelling relationships between time-series data in medicine. We use exploratory graphical methods to better understand the relationship between a time-series reponse and a number of potential covariates. Graphical methods are also used to examine any remaining information in the residuals from these models. RESULTS We applied exploratory graphical methods to a time-series data set consisting of daily counts of hospital admissions for asthma, and pollution and climatic variables. We provide an overview of the most recent and widely applicable data-visualisation methods for portraying and analysing epidemiological time series. DISCUSSION Exploratory graphical analysis allows insight into the underlying structure of observations in a data set, and graphical methods for diagnostic purposes after model-fitting provide insight into the fitted model and its inadequacies.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59835663","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}
Pub Date : 2001-01-01DOI: 10.1080/135952201753336960
K. Boucher, R. Kerber
BACKGROUND Several measures of familial disease aggregation have been proposed, but only a few of these are designed to be implemented at the individual level. We evaluate two of them in the context of breast-cancer incidence. METHODS A population-based cohort consisting of 114 429 women born between 1874 and 1931 and at risk for breast cancer after 1965 was identified by linking the Utah Population Data Base and the Utah Cancer Registry. Two competing methods were used to obtain predictors of familial aggregation of risk: the number of first-degree relatives with breast cancer (NIST) and the familial standardised incidence ratio (FSIR), which weights the disease status of relatives based on their degree of relatedness with the proband. Relative risks were estimated using Mantel-Haenszel. Poisson regression and spline regression methods. The age-dependent hazard function was also estimated. RESULTS Compared to a baseline category containing 91.5% of the subjects, the 0.7% of subjects identified as high risk using the FSIR criterion had a relative risk of about 2.8, while those identified as high risk using the NIST criterion had a relative risk of 2.0. Moderate-risk subjects had a relative risk of about 1.75 using either criterion. FSIR was a significant predictor of risk even for those with no affected first-degree relatives. No decline in the baseline risk was observed at advanced ages. CONCLUSIONS FSIR appears to be a better predictor of breast-cancer risk than NIST, particularly for high-risk subjects.
{"title":"Measures of familial aggregation as predictors of breast-cancer risk.","authors":"K. Boucher, R. Kerber","doi":"10.1080/135952201753336960","DOIUrl":"https://doi.org/10.1080/135952201753336960","url":null,"abstract":"BACKGROUND Several measures of familial disease aggregation have been proposed, but only a few of these are designed to be implemented at the individual level. We evaluate two of them in the context of breast-cancer incidence. METHODS A population-based cohort consisting of 114 429 women born between 1874 and 1931 and at risk for breast cancer after 1965 was identified by linking the Utah Population Data Base and the Utah Cancer Registry. Two competing methods were used to obtain predictors of familial aggregation of risk: the number of first-degree relatives with breast cancer (NIST) and the familial standardised incidence ratio (FSIR), which weights the disease status of relatives based on their degree of relatedness with the proband. Relative risks were estimated using Mantel-Haenszel. Poisson regression and spline regression methods. The age-dependent hazard function was also estimated. RESULTS Compared to a baseline category containing 91.5% of the subjects, the 0.7% of subjects identified as high risk using the FSIR criterion had a relative risk of about 2.8, while those identified as high risk using the NIST criterion had a relative risk of 2.0. Moderate-risk subjects had a relative risk of about 1.75 using either criterion. FSIR was a significant predictor of risk even for those with no affected first-degree relatives. No decline in the baseline risk was observed at advanced ages. CONCLUSIONS FSIR appears to be a better predictor of breast-cancer risk than NIST, particularly for high-risk subjects.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59836347","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}
Pub Date : 2001-01-01DOI: 10.1080/135952201317225507
Skalkidis Il
{"title":"A tentative comparison of research activities between the Athens Department of Hygiene and Epidemiology and other Departments of Epidemiology in the USA and European community.","authors":"Skalkidis Il","doi":"10.1080/135952201317225507","DOIUrl":"https://doi.org/10.1080/135952201317225507","url":null,"abstract":"","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59835293","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}
Pub Date : 2001-01-01DOI: 10.1080/13595220152601783
T. Friede, M. Kieser
BACKGROUND Adaptive two-stage designs are a flexible tool in drug development and have the potential for an improvement of power over one-stage designs. In an adaptive two-stage dose-response trial, the dose-response relationship is examined in a preplanned interim analysis. If efficacy has not yet been proved, a subset of the most favourable doses may be selected for the second stage. This design offers the opportunity to combine dose selection and proof of efficacy within a single trial. METHODS We consider a change-point regression model describing the dose-response relationship. In this framework, selection of the most favourable dose can be achieved by estimating the change point in the regression model. We introduce a change-point estimator that can be optimised by a loss-function based approach, taking into account both efficacy and safety aspects. We investigate the power characteristics of our approach. RESULTS The proposed procedure performs well with regard to statistical power. The proposal demonstrates the feasibility of simultaneous modelling of efficacy and safety aspects by a loss-function based approach. CONCLUSION Adaptive two-stage designs, in conjunction with an elaborated dose-selection rule, can support the decision about the suitable dose to use, leading to a considerable gain in power (or saving in sample size) and possibly speeding up the time-to-market in drug development.
{"title":"A loss-function based approach for dose selection in two-stage dose-response trials.","authors":"T. Friede, M. Kieser","doi":"10.1080/13595220152601783","DOIUrl":"https://doi.org/10.1080/13595220152601783","url":null,"abstract":"BACKGROUND Adaptive two-stage designs are a flexible tool in drug development and have the potential for an improvement of power over one-stage designs. In an adaptive two-stage dose-response trial, the dose-response relationship is examined in a preplanned interim analysis. If efficacy has not yet been proved, a subset of the most favourable doses may be selected for the second stage. This design offers the opportunity to combine dose selection and proof of efficacy within a single trial. METHODS We consider a change-point regression model describing the dose-response relationship. In this framework, selection of the most favourable dose can be achieved by estimating the change point in the regression model. We introduce a change-point estimator that can be optimised by a loss-function based approach, taking into account both efficacy and safety aspects. We investigate the power characteristics of our approach. RESULTS The proposed procedure performs well with regard to statistical power. The proposal demonstrates the feasibility of simultaneous modelling of efficacy and safety aspects by a loss-function based approach. CONCLUSION Adaptive two-stage designs, in conjunction with an elaborated dose-selection rule, can support the decision about the suitable dose to use, leading to a considerable gain in power (or saving in sample size) and possibly speeding up the time-to-market in drug development.","PeriodicalId":80024,"journal":{"name":"Journal of epidemiology and biostatistics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"59835359","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}
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