The Experts below are selected from a list of 288 Experts worldwide ranked by ideXlab platform
Gary G Koch - One of the best experts on this subject based on the ideXlab platform.
-
Statistical Projection of Clinical Subsample Estimates to a Survey Population
Journal of Periodontology, 2007Co-Authors: Lisa M Lavange, Gary G KochAbstract:Background: The goal of public health research often involves estimating clinical outcomes for a broad target Population. The gold standard for the basis of such inference is a nationally representative Survey that includes a clinical component. The cost of this gold standard can be prohibitive, and alternative approaches are needed. We propose a statistical methodology for projecting estimates from a clinical subsample to a larger Survey Population that has utility in periodontal research. Methods: The statistical methodology consists of fitting prediction models to clinical outcome variables that are available only for a subset of the Survey Population. Variables measured on the larger Survey Population are included in the model as predictors. The resulting prediction equations are applied to the entire Survey Population to produce estimates of prevalence for the clinical outcomes of interest. Methods for computing variance estimates for the model-based predictions also are proposed. Results: This projection methodology was developed originally for use with a nationally representative sample of the veteran Population in the United States as part of the National Vietnam Veterans Readjustment Study. Details of the projection methodology and illustration of its use are provided. Issues associated with the application of this methodology to periodontal research are discussed. Conclusions: The proposed projection methodology supports valid inference about clinical outcomes to a broad Population using data from a more narrowly defined clinical subsample. This approach is useful in addressing important public health questions until such time as a nationally representative clinical study can be undertaken.
-
Statistical projection of clinical subsample estimates to a Survey Population.
Journal of periodontology, 2007Co-Authors: Lisa M Lavange, Gary G KochAbstract:The goal of public health research often involves estimating clinical outcomes for a broad target Population. The gold standard for the basis of such inference is a nationally representative Survey that includes a clinical component. The cost of this gold standard can be prohibitive, and alternative approaches are needed. We propose a statistical methodology for projecting estimates from a clinical subsample to a larger Survey Population that has utility in periodontal research. The statistical methodology consists of fitting prediction models to clinical outcome variables that are available only for a subset of the Survey Population. Variables measured on the larger Survey Population are included in the model as predictors. The resulting prediction equations are applied to the entire Survey Population to produce estimates of prevalence for the clinical outcomes of interest. Methods for computing variance estimates for the model-based predictions also are proposed. This projection methodology was developed originally for use with a nationally representative sample of the veteran Population in the United States as part of the National Vietnam Veterans Readjustment Study. Details of the projection methodology and illustration of its use are provided. Issues associated with the application of this methodology to periodontal research are discussed. The proposed projection methodology supports valid inference about clinical outcomes to a broad Population using data from a more narrowly defined clinical subsample. This approach is useful in addressing important public health questions until such time as a nationally representative clinical study can be undertaken.
-
Statistical Projection of Clinical Subsample Estimates to a Survey Population.
Journal of periodontology, 2007Co-Authors: Lisa M Lavange, Gary G KochAbstract:The goal of public health research often involves estimating clinical outcomes for a broad target Population. The gold standard for the basis of such inference is a nationally representative Survey that includes a clinical component. The cost of this gold standard can be prohibitive, and alternative approaches are needed. We propose a statistical methodology for projecting estimates from a clinical subsample to a larger Survey Population that has utility in periodontal research. The statistical methodology consists of fitting prediction models to clinical outcome variables that are available only for a subset of the Survey Population. Variables measured on the larger Survey Population are included in the model as predictors. The resulting prediction equations are applied to the entire Survey Population to produce estimates of prevalence for the clinical outcomes of interest. Methods for computing variance estimates for the model-based predictions also are proposed. This projection methodology was developed originally for use with a nationally representative sample of the veteran Population in the United States as part of the National Vietnam Veterans Readjustment Study. Details of the projection methodology and illustration of its use are provided. Issues associated with the application of this methodology to periodontal research are discussed. The proposed projection methodology supports valid inference about clinical outcomes to a broad Population using data from a more narrowly defined clinical subsample. This approach is useful in addressing important public health questions until such time as a nationally representative clinical study can be undertaken. © 2007 American Academy of Periodontology.
Lisa M Lavange - One of the best experts on this subject based on the ideXlab platform.
-
Statistical Projection of Clinical Subsample Estimates to a Survey Population
Journal of Periodontology, 2007Co-Authors: Lisa M Lavange, Gary G KochAbstract:Background: The goal of public health research often involves estimating clinical outcomes for a broad target Population. The gold standard for the basis of such inference is a nationally representative Survey that includes a clinical component. The cost of this gold standard can be prohibitive, and alternative approaches are needed. We propose a statistical methodology for projecting estimates from a clinical subsample to a larger Survey Population that has utility in periodontal research. Methods: The statistical methodology consists of fitting prediction models to clinical outcome variables that are available only for a subset of the Survey Population. Variables measured on the larger Survey Population are included in the model as predictors. The resulting prediction equations are applied to the entire Survey Population to produce estimates of prevalence for the clinical outcomes of interest. Methods for computing variance estimates for the model-based predictions also are proposed. Results: This projection methodology was developed originally for use with a nationally representative sample of the veteran Population in the United States as part of the National Vietnam Veterans Readjustment Study. Details of the projection methodology and illustration of its use are provided. Issues associated with the application of this methodology to periodontal research are discussed. Conclusions: The proposed projection methodology supports valid inference about clinical outcomes to a broad Population using data from a more narrowly defined clinical subsample. This approach is useful in addressing important public health questions until such time as a nationally representative clinical study can be undertaken.
-
Statistical projection of clinical subsample estimates to a Survey Population.
Journal of periodontology, 2007Co-Authors: Lisa M Lavange, Gary G KochAbstract:The goal of public health research often involves estimating clinical outcomes for a broad target Population. The gold standard for the basis of such inference is a nationally representative Survey that includes a clinical component. The cost of this gold standard can be prohibitive, and alternative approaches are needed. We propose a statistical methodology for projecting estimates from a clinical subsample to a larger Survey Population that has utility in periodontal research. The statistical methodology consists of fitting prediction models to clinical outcome variables that are available only for a subset of the Survey Population. Variables measured on the larger Survey Population are included in the model as predictors. The resulting prediction equations are applied to the entire Survey Population to produce estimates of prevalence for the clinical outcomes of interest. Methods for computing variance estimates for the model-based predictions also are proposed. This projection methodology was developed originally for use with a nationally representative sample of the veteran Population in the United States as part of the National Vietnam Veterans Readjustment Study. Details of the projection methodology and illustration of its use are provided. Issues associated with the application of this methodology to periodontal research are discussed. The proposed projection methodology supports valid inference about clinical outcomes to a broad Population using data from a more narrowly defined clinical subsample. This approach is useful in addressing important public health questions until such time as a nationally representative clinical study can be undertaken.
-
Statistical Projection of Clinical Subsample Estimates to a Survey Population.
Journal of periodontology, 2007Co-Authors: Lisa M Lavange, Gary G KochAbstract:The goal of public health research often involves estimating clinical outcomes for a broad target Population. The gold standard for the basis of such inference is a nationally representative Survey that includes a clinical component. The cost of this gold standard can be prohibitive, and alternative approaches are needed. We propose a statistical methodology for projecting estimates from a clinical subsample to a larger Survey Population that has utility in periodontal research. The statistical methodology consists of fitting prediction models to clinical outcome variables that are available only for a subset of the Survey Population. Variables measured on the larger Survey Population are included in the model as predictors. The resulting prediction equations are applied to the entire Survey Population to produce estimates of prevalence for the clinical outcomes of interest. Methods for computing variance estimates for the model-based predictions also are proposed. This projection methodology was developed originally for use with a nationally representative sample of the veteran Population in the United States as part of the National Vietnam Veterans Readjustment Study. Details of the projection methodology and illustration of its use are provided. Issues associated with the application of this methodology to periodontal research are discussed. The proposed projection methodology supports valid inference about clinical outcomes to a broad Population using data from a more narrowly defined clinical subsample. This approach is useful in addressing important public health questions until such time as a nationally representative clinical study can be undertaken. © 2007 American Academy of Periodontology.
Elizabeth A. Stuart - One of the best experts on this subject based on the ideXlab platform.
-
Generalizing randomized trial findings to a target Population using complex Survey Population data.
Statistics in medicine, 2020Co-Authors: Benjamin Ackerman, Catherine R. Lesko, Juned Siddique, Ryoko Susukida, Elizabeth A. StuartAbstract:Randomized trials are considered the gold standard for estimating causal effects. Trial findings are often used to inform policy and programming efforts, yet their results may not generalize well to a relevant target Population due to potential differences in effect moderators between the trial and Population. Statistical methods have been developed to improve generalizability by combining trials and Population data, and weighting the trial to resemble the Population on baseline covariates. Large-scale Surveys in fields such as health and education with complex Survey designs are a logical source for Population data; however, there is currently no best practice for incorporating Survey weights when generalizing trial findings to a complex Survey. We propose and investigate ways to incorporate Survey weights in this context. We examine the performance of our proposed estimator through simulations in comparison to estimators that ignore the complex Survey design. We then apply the methods to generalize findings from two trials-a lifestyle intervention for blood pressure reduction and a web-based intervention to treat substance use disorders-to their respective target Populations using Population data from complex Surveys. The work highlights the importance in properly accounting for the complex Survey design when generalizing trial findings to a Population represented by a complex Survey sample.
-
Generalizing Randomized Trial Findings to a Target Population using Complex Survey Population Data
arXiv: Methodology, 2020Co-Authors: Benjamin Ackerman, Catherine R. Lesko, Juned Siddique, Ryoko Susukida, Elizabeth A. StuartAbstract:Randomized trials are considered the gold standard for estimating causal effects. Trial findings are often used to inform policy and programming efforts, yet their results may not generalize well to a relevant target Population due to potential differences in effect moderators between the trial and Population. Statistical methods have been developed to improve generalizability by combining trials and Population data, and weighting the trial to resemble the Population on baseline covariates.Large-scale Surveys in fields such as health and education with complex Survey designs are a logical source for Population data; however, there is currently no best practice for incorporating Survey weights when generalizing trial findings to a complex Survey. We propose and investigate ways to incorporate Survey weights in this context. We examine the performance of our proposed estimator in simulations by comparing its performance to estimators that ignore the complex Survey design.We then apply the methods to generalize findings from two trials - a lifestyle intervention for blood pressure reduction and a web-based intervention to treat substance use disorders - to their respective target Populations using Population data from complex Surveys. The work highlights the importance in properly accounting for the complex Survey design when generalizing trial findings to a Population represented by a complex Survey sample.
Robert Stewart - One of the best experts on this subject based on the ideXlab platform.
-
Relationship between depressive symptoms, anemia, and iron status in older residents from a national Survey Population.
Psychosomatic medicine, 2012Co-Authors: Robert Stewart, Vasant HiraniAbstract:OBJECTIVE To investigate the association between iron deficiency status and depressive symptoms in a national community sample of older people. METHODS Cross-sectional data were analyzed from 1875 participants 65 years and older who had participated in the 2005 Health Survey for England. Serum hemoglobin (Hb), ferritin, and transferrin receptor levels and depressive symptoms (Geriatric Depression Scale) had been measured. Covariates included age, sex, occupation, multivitamin intake, smoking status, body mass index, hypertension, heart disease, stroke, diabetes, and cancer. RESULTS Depressive symptoms were associated with anemia (Hb
-
Relationship between vitamin D levels and depressive symptoms in older residents from a national Survey Population.
Psychosomatic medicine, 2010Co-Authors: Robert Stewart, Vasant HiraniAbstract:To investigate the association between vitamin D deficiency and depressive symptoms in a national community sample of older people. Vitamin D deficiency is common in older people with potential effects on mood. Data were analyzed from 2070 participants aged ≥65 years who had participated in the 2005 Health Survey for England. Serum 25-hydroxy vitamin D (25(OH)D) levels and depressive symptoms (Geriatric Depression Scale) had been measured. Covariates included age, sex, social class, season of examination, and physical health status. Depressive symptoms were associated with clinical vitamin D deficiency (25(OH)D levels <10 ng/mL; present in 9.8%) independent of other covariates but not with broader deficiency states. This association was not modified by season of examination. Vitamin D deficiency is associated with late-life depression in northern latitudes.
-
Age variation in life events and their relationship with common mental disorders in a national Survey Population
Social psychiatry and psychiatric epidemiology, 2007Co-Authors: Vesna Jordanova, Robert Stewart, Paul Bebbington, Traolach S. Brugha, James Lindesay, Rachel Jenkins, David Goldberg, N Singleton, Martin Prince, Howard MeltzerAbstract:Background Life events (LEs) are recognised to be important risk factors for common mental disorders (CMD). Their prominence may vary across age groups but this issue has received little systematic investigation.
-
Insomnia comorbidity and impact and hypnotic use by age group in a national Survey Population aged 16 to 74 years
Sleep, 2006Co-Authors: Robert Stewart, Alain Besset, Paul Bebbington, Traolach S. Brugha, James Lindesay, Rachel Jenkins, Nicola Singleton, Howard MeltzerAbstract:Study Objectives: To compare age-group differences in somatic/psychiatric comorbidity, impact, and pharmacotherapy associated with sleep disturbance across a broad adult age range. Design: Cross-sectional national mental health Survey. Setting: Adults living in private households in England, Scotland, and Wales. Participants: 8,580 people aged 16 to 74 years. Measurements and Results: Insomnia (4 symptom/syndrome definitions), depression, generalized anxiety disorder, and daytime fatigue were defined from the revised Clinical Interview Schedule. Any insomnia was reported by 37% of the sample, moderate insomnia by 12%, insomnia with fatigue by 13%, and symptoms fulfilling diagnostic criteria for primary/secondary insomnia by 5%. All categories of insomnia were associated with mental disorders, worse physical health, and fatigue to a similar degree in all decade age groups. The associations between insomnia categories and separated, divorced, or widowed marital status were strongest in younger participants. Insomnia categories were of longer reported duration and more strongly associated with worse physical health-related quality of life (SF-12) in older age groups. For participants with any definition of insomnia, benzodiazepine hypnotics were more commonly reported in older age groups. Conclusions: The association between insomnia and impaired quality of life is most pronounced in older age groups. Associations with physical and mental health status and those with daytime fatigue do not vary in strength between age groups. Older people with insomnia in this Population were more likely to be taking benzodiazepine hypnotics. Keywords : Insomnia, national Survey, depressive disorder, generalised anxiety disorder, quality of life, fatigue, hypnotic use, ageing Citation: Stewart R; Besset A; Bebbington P et al. Insomnia comorbidity and impact and hypnotic use by age group in a national Survey Population aged 16 to 74 years.
Vasant Hirani - One of the best experts on this subject based on the ideXlab platform.
-
Relationship between depressive symptoms, anemia, and iron status in older residents from a national Survey Population.
Psychosomatic medicine, 2012Co-Authors: Robert Stewart, Vasant HiraniAbstract:OBJECTIVE To investigate the association between iron deficiency status and depressive symptoms in a national community sample of older people. METHODS Cross-sectional data were analyzed from 1875 participants 65 years and older who had participated in the 2005 Health Survey for England. Serum hemoglobin (Hb), ferritin, and transferrin receptor levels and depressive symptoms (Geriatric Depression Scale) had been measured. Covariates included age, sex, occupation, multivitamin intake, smoking status, body mass index, hypertension, heart disease, stroke, diabetes, and cancer. RESULTS Depressive symptoms were associated with anemia (Hb
-
Relationship between vitamin D levels and depressive symptoms in older residents from a national Survey Population.
Psychosomatic medicine, 2010Co-Authors: Robert Stewart, Vasant HiraniAbstract:To investigate the association between vitamin D deficiency and depressive symptoms in a national community sample of older people. Vitamin D deficiency is common in older people with potential effects on mood. Data were analyzed from 2070 participants aged ≥65 years who had participated in the 2005 Health Survey for England. Serum 25-hydroxy vitamin D (25(OH)D) levels and depressive symptoms (Geriatric Depression Scale) had been measured. Covariates included age, sex, social class, season of examination, and physical health status. Depressive symptoms were associated with clinical vitamin D deficiency (25(OH)D levels <10 ng/mL; present in 9.8%) independent of other covariates but not with broader deficiency states. This association was not modified by season of examination. Vitamin D deficiency is associated with late-life depression in northern latitudes.
-
Dental health and cognitive impairment in an English National Survey Population
J AM GERIATR SOC, 2007Co-Authors: Vasant HiraniAbstract:OBJECTIVES: To investigate the association between dental health and cognitive impairment and to examine the extent to which dental status accounts for the association between cognitive impairment and low body mass index (BMI) in a national Survey sample.DESIGN: A secondary analysis of data from the Health Survey for England 2000.SETTING: A nationally representative cross-sectional Population Survey.PARTICIPANTS: Two thousand four hundred sixty-three adults aged 65 and older living in private households and 1,569 adults aged 65 and older living in care homes.MEASUREMENTS: Data collected by interview (self-reported or by proxy) included age, sex, level of education, disability, BMI, dental status, and cognitive function (Abbreviated Mental Test Score).RESULTS: Less than half of the community sample (40.4%) and 67.9% of the care home sample were edentulous; lack of teeth was significantly associated with cognitive impairment (odds ratio=3.59, 95% confidence interval=2.36-5.47). This association remained strong after adjustment for other covariates only in the community sample. Cognitive impairment was associated with lower BMI in both samples, but dental status did not explain this.CONCLUSION: Poor dentition is associated with cognitive impairment. Nutritional status in people with cognitive impairment is recognized to be at risk. Although dental health did not account for the association between cognitive impairment and low BMI in this sample, other possible nutritional consequences require further evaluation.
