BACKGROUND Within-person variability in measured values of a risk factor can bias its association with disease. We investigated the extent of regression dilution bias in calculated variables and its implications for comparing the aetiological associations of risk factors. METHODS Using a numerical illustration and repeats from 42,300 individuals (12 cohorts), we estimated regression dilution ...

The measurement of urinary total protein continues to have a place in the repertoire of clinical laboratory tests, particularly in the clinical assessment of patients with renal disease. Although the test volume is often modest, there exists the need to perform the assay on the major automated chemistry analyzers currently in use in most hospital laboratories. We have evaluated the performance ...

An analytical method was developed for Ca determination in ultrapure water, concentrated acids and hydrogen peroxide by ICP-MS, using CH3F as reaction gas in the dynamic reaction cell (DRC) and isotopic dilution (ID) as strategy of calibration for improve the accuracy and allow interferencefree Ca determination.

A new indicator dilution technique for measurement of cardiac output is described. Lithium chloride is injected via a central venous catheter and its dilution curve measured in arterial blood using a lithium-selective electrode. We assessed the lithium dilution cardiac output measurement (LiDCO) and a conventional thermodilution cardiac output measurement (ThDCO) by comparing the results of bot...

CONTEXT Qualitative studies assessing the impact of the household delivery of family planning services on women's social status have yielded contradictory findings. Given the resumption of these services in Bangladesh in 2003, it is important to reevaluate the social impact of the doorstep program using quantitative techniques. METHODS Longitudinal and cross-sectional data from 3,783 women us...

BACKGROUND Free thyroxine (FT4) assays may exhibit biases that are related to serum T4 binding capacity (sBC). We describe two tests that can be used to assess the presence and magnitude of sBC-dependent biases in FT4 assays. METHODS We used a direct equilibrium dialysis FT4 assay as the reference method and compared the results obtained with those of the FT4 assays under investigation, in pa...

In 2013, the World Health Organization (WHO) called for joint surveillance of population salt and iodine intakes using urinary analysis. 24-h urine collection is considered the gold standard for salt intake assessment, but there is an emerging consensus that casual urine sampling can provide comparable information for population-level surveillance. Our review covers the use of the urinary sodiu...

In human and hand pose estimation, heatmaps are a crucial intermediate representation for body or keypoint. Two popular methods to decode the heatmap into final joint coordinate via an argmax, as done in detection, softmax expectation, integral regression. Integral regression is learnable end-to-end, but has lower accuracy than detection. This paper uncovers induced bias from that results combi...