background: use of single measurement of risk factors can distort their estimated effects, due to random error in measurements. the aim of this study was to examine the extent of underestimation in the estimated effect of common variables in physical exam i.e. systolic and diastolic blood pressure (sbp, dbp) and body mass index (bmi) on cardiovascular diseases in tehran lipid and glucose study ...

Department of Obstetrics & Gynaecology, University of British Columbia, Vancouver, Canada Department of Epidemiology, Biostatistics, and Occupational Health, McGill University, Purvis Hall, 1020 Avenue des Pins Ouest, Montreal QC, Canada H3A 1A2 Institute of Social and Preventive Medicine (IUMSP), University Hospital Centre and University of Lausanne, Lausanne, Switzerland Correspondence to: J ...

conclusions using baseline measurements of lipids led to considerable underestimation in the association of these factors with cvd outcome in tlgs. the underestimation increased with time interval between baseline and follow-up measurements for tc and tg. tc had more attenuation on estimated hr due to stronger relation with cvd risk. results by parametric method, based on reexamination three ye...

BACKGROUND Within-person variability in measured values of a risk factor can bias its association with disease. The extent of this regression dilution bias for plasma fibrinogen was investigated using repeat measurement data collected at varying time intervals on 27 247 adults in 15 prospective studies. METHODS Regression dilution ratios (RDRs) were estimated from a linear regression of repea...

BACKGROUND Random errors in measurement of a risk factor will introduce downward bias of an estimated association to a disease or a disease marker. This phenomenon is called regression dilution bias. A bias correction may be made with data from a validity study or a reliability study. AIMS AND METHODS In this article we give a non-technical description of designs of reliability studies with e...

In this study we suggest a covariance structure model to estimate intergenerational income correlations. Within this framework we adjust for lifecycle bias which arises when lifetime earnings are approximated by current income. Furthermore, the suggested empirical strategy is immune to the attenuation bias problem of linear models. This is a particularly desirable feature when only small survey...

The observational data relating salt and blood pressure (excluding ENTERS ALT) are reviewed. Important methodological difficulties and biases are inherent to both acrossand withinpopulation studies and confuse their interpretation. Across-population studies are positive but rely on data drawn from the international literature based on a variety of unstandardized field methods; they are prone to...

Background—Elevated lipoprotein(a) levels are associated with myocardial infarction (MI) in some but not all studies. Limitations of previous studies include lack of risk estimates for extreme lipoprotein(a) levels, measurements in long-term frozen samples, no correction for regression dilution bias, and lack of absolute risk estimates in the general population. We tested the hypothesis that ex...

Worldwide cardiovascular diseases account for half of all deaths in middle age (and considerable additional disability) and one third of all deaths in old age. Most of these deaths involve ischaemic heart disease (IHD) or stroke. Epidemiological studies carried out over the last half century have shown that cigarette smoking, elevated blood pressure and dyslipidaemia increase the risk of cardio...