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Family History Information (family + history_information)

Distribution by Scientific Domains
Medical Sciences87%

Selected Abstracts

Subject and informant characteristics influence the reliability and validity of family history information: an analysis based on the generalized estimating equations approach

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 2 2000
Reinhard Heun
Abstract Family history information is a necessary surrogate for unavailable interview information in family studies. However, the reliability and validity of such information has rarely been assessed during the conduct of family studies. This paper presents a reanalysis of data on the reliability and validity of family history information for dementia and depression using the general estimation equations approach. All available relatives of patients and controls were interviewed and questioned about the psychiatric morbidity of other family members. Interinformant reliability of this family history information was evaluated as well as factors influencing this information. The validity of family history was investigated by comparing the informant derived diagnoses with interview-derived diagnoses. To account for possible lack of independence of family history provided by several family members on other family members, the generalized estimating equations (GEE) were used in statistical analysis. The interinformant reliability for depression (kappa = 0.13) was low. It was fair for dementia (kappa = 0.34). The informants more frequently agreed about the diagnosis of dementia when the subject was older. The sensitivity of family history was 35.2% for dementia and 31.8% for depression. The specificity of family history information was generally above 97%. The sensitivity of family history increased significantly with the severity of both disorders. The sensitivity of the family history for dementia was higher when the informant was a first-degree relative, when he was younger and when the index subject of the family suffered from dementia. The specificity of the family history was slightly reduced with higher age. The observed low sensitivity of family history information leads to underestimation of psychiatric disorders. The informants provide more useful information on more severe disorders. The sensitivity of family history was higher in families with an affected index subject than in control families, so familial aggregation of dementia might be overestimated in studies using the family history method. Copyright © 2000 Whurr Publishers Ltd. [source]

Family history information on essential tremor: Potential biases related to the source of the cases

MOVEMENT DISORDERS, Issue 2 2001
Elan D. Louis MD
Abstract The proportion of essential tremor (ET) cases that can be attributed to genetic factors is unknown; estimates range from 17,100%. One possible reason for this variability is that clinic and community cases may differ with regard to family history of ET. This is because clinic patients are self-selected and represent as few as 0.5% of all ET cases. Our goal was to determine whether ET cases ascertained from a clinic differed from those ascertained from a community in terms of the family history information that they provided. Subjects (57 clinic, 64 community) underwent a family history interview. Clinic cases were 4.73 times more likely to report an affected relative than were community cases. We conclude that there was a substantial difference between our clinic and community ET cases in terms of the information they provided regarding their family history. Selection and reporting biases could have accounted for this difference. Because of these biases, the source of the cases must be taken into consideration when investigators are trying to synthesize the widely variable results of studies that have estimated the genetic contribution to ET. © 2001 Movement Disorder Society. [source]

Multiple genetic tests for susceptibility to smoking do not outperform simple family history

ADDICTION, Issue 1 2009
Coral E. Gartner
ABSTRACT Aims To evaluate the utility of using predictive genetic screening of the population for susceptibility to smoking. Methods The results of meta-analyses of genetic association studies of smoking behaviour were used to create simulated data sets using Monte Carlo methods. The ability of the genetic tests to screen for smoking was assessed using receiver operator characteristic curve analysis. The result was compared to prediction using simple family history information. To identify the circumstances in which predictive genetic testing would potentially justify screening we simulated tests using larger numbers of alleles (10, 15 and 20) that varied in prevalence from 10 to 50% and in strength of association [relative risks (RRs) of 1.2,2.1]. Results A test based on the RRs and prevalence of five susceptibility alleles derived from meta-analyses of genetic association studies of smoking performed similarly to chance and no better than the prediction based on simple family history. Increasing the number of alleles from five to 20 improved the predictive ability of genetic screening only modestly when using genes with the effect sizes reported to date. Conclusions This panel of genetic tests would be unsuitable for population screening. This situation is unlikely to be improved upon by screening based on more genetic tests. Given the similarity with associations found for other polygenic conditions, our results also suggest that using multiple genes to screen the general population for genetic susceptibility to polygenic disorders will be of limited utility. [source]

Subject and informant characteristics influence the reliability and validity of family history information: an analysis based on the generalized estimating equations approach

INTERNATIONAL JOURNAL OF METHODS IN PSYCHIATRIC RESEARCH, Issue 2 2000
Reinhard Heun
Abstract Family history information is a necessary surrogate for unavailable interview information in family studies. However, the reliability and validity of such information has rarely been assessed during the conduct of family studies. This paper presents a reanalysis of data on the reliability and validity of family history information for dementia and depression using the general estimation equations approach. All available relatives of patients and controls were interviewed and questioned about the psychiatric morbidity of other family members. Interinformant reliability of this family history information was evaluated as well as factors influencing this information. The validity of family history was investigated by comparing the informant derived diagnoses with interview-derived diagnoses. To account for possible lack of independence of family history provided by several family members on other family members, the generalized estimating equations (GEE) were used in statistical analysis. The interinformant reliability for depression (kappa = 0.13) was low. It was fair for dementia (kappa = 0.34). The informants more frequently agreed about the diagnosis of dementia when the subject was older. The sensitivity of family history was 35.2% for dementia and 31.8% for depression. The specificity of family history information was generally above 97%. The sensitivity of family history increased significantly with the severity of both disorders. The sensitivity of the family history for dementia was higher when the informant was a first-degree relative, when he was younger and when the index subject of the family suffered from dementia. The specificity of the family history was slightly reduced with higher age. The observed low sensitivity of family history information leads to underestimation of psychiatric disorders. The informants provide more useful information on more severe disorders. The sensitivity of family history was higher in families with an affected index subject than in control families, so familial aggregation of dementia might be overestimated in studies using the family history method. Copyright © 2000 Whurr Publishers Ltd. [source]

Family history information on essential tremor: Potential biases related to the source of the cases

MOVEMENT DISORDERS, Issue 2 2001
Elan D. Louis MD
Abstract The proportion of essential tremor (ET) cases that can be attributed to genetic factors is unknown; estimates range from 17,100%. One possible reason for this variability is that clinic and community cases may differ with regard to family history of ET. This is because clinic patients are self-selected and represent as few as 0.5% of all ET cases. Our goal was to determine whether ET cases ascertained from a clinic differed from those ascertained from a community in terms of the family history information that they provided. Subjects (57 clinic, 64 community) underwent a family history interview. Clinic cases were 4.73 times more likely to report an affected relative than were community cases. We conclude that there was a substantial difference between our clinic and community ET cases in terms of the information they provided regarding their family history. Selection and reporting biases could have accounted for this difference. Because of these biases, the source of the cases must be taken into consideration when investigators are trying to synthesize the widely variable results of studies that have estimated the genetic contribution to ET. © 2001 Movement Disorder Society. [source]

Gail Model Risk Factors: Impact of Adding an Extended Family History for Breast Cancer

THE BREAST JOURNAL, Issue 3 2008
Anna Crispo ScD
Abstract:, An approach commonly used in estimating breast cancer risk is the Gail model. The objective of this study was to evaluate the feasibility and impact of adding extended family history as a new breast cancer risk factor into the Gail model. The data of the present study include cases with breast cancer and hospitalized controls recruited in the National Cancer Institute of Naples (southern Italy) between 1997 and 2000. We compared the first-degree relative (FDR) risk factor (standard Gail model) with the second-degree relative (SDR) information; and the FDR risk factor (standard Gail model) with the combination of FDR and SDR. We computed the c-statistic by comparing the risks found in our population to those in Gail-US population. The concordance for the model with FDR was 0.55 (95% CI 0.53,0.58), the model with SDR shows a modest but significant discriminatory accuracy (0.56, 95% CI 0.53,0.59), and the combination of FDR+SDR gave the concordance statistic of 0.57 (95% CI 0.54,0.60), indicating a good comparison between the two models. The results of our study show that extended family history information could be useful to improve the discriminatory power of the Gail model risk factors. [source]

A Frailty-Model-Based Approach to Estimating the Age-Dependent Penetrance Function of Candidate Genes Using Population-Based Case-Control Study Designs: An Application to Data on the BRCA1 Gene

BIOMETRICS, Issue 4 2009
Lu Chen
Summary The population-based case,control study design is perhaps one of, if not the most, commonly used designs for investigating the genetic and environmental contributions to disease risk in epidemiological studies. Ages at onset and disease status of family members are routinely and systematically collected from the participants in this design. Considering age at onset in relatives as an outcome, this article is focused on using the family history information to obtain the hazard function, i.e., age-dependent penetrance function, of candidate genes from case,control studies. A frailty-model-based approach is proposed to accommodate the shared risk among family members that is not accounted for by observed risk factors. This approach is further extended to accommodate missing genotypes in family members and a two-phase case,control sampling design. Simulation results show that the proposed method performs well in realistic settings. Finally, a population-based two-phase case,control breast cancer study of the BRCA1 gene is used to illustrate the method. [source]