Limit Of Confidence Interval Research Articles

Agreement and bias in the estimation of fat free mass using bioelectrical impedance analysis and a resistance and reactance- based formula for the Mexican adults: A study from Merida, Yucatan

Bioelectrical impedance analysis (BIA) is used to estimate body composition characteristics. The values of body fat and fat free mass (FFM) are obtained as per algorithms of the device that are often unknown to the researchers. Some models of the analyzer provide resistance and reactance values that may be useful to estimate FFM. Objective of the present study was to test the agreement and proportional bias in the estimation of FFM obtained through BIA and that derived from the resistance and reactance values using a formula for Mexican adults. A cross-sectional study was carried out in 2019 selected 60 university male students aged 21 to 23 years from Merida, Yucatan. A multifrequency whole body bioelectrical impedance analyzer Tanita MC 180 MA (Tanita Corporation, Tokyo-Japan) was used to evaluate body composition characteristics. The device gives estimates of FFM in kg (based on algorithm) and the resistance and reactance values (ohms). There is an existing formula for Mexican adults to estimate FFM (FFM_FOR) from the resistance and reactance values obtained through BIA. An agreement between the two estimates of FFM has been tested using Bland-Altman plot and linear regression analysis. Mean value of age of the participants was 21.88 years. FFM estimated by BIA (FFM_BIA = 41.44 kg) and that derived from FFM_FOR (41.36 kg) had signifi cant intraclass correlation coeffi cient (ICC) (Cronbach’s alpha = 0.99, p<0.0001). One sample t-test estimating the diff erence of mean values between FFM_BIA and FFM_FOR was not signifi cant (t = 1.37, mean diff erence -0.02, p = 0.18). The Bland-Altman plot shows almost all data points lie within 95% confi dence interval limits. A linear regression analysis using the diff erence of FFM values as dependent variable and the average of the measurements as the independent variable showed no signifi cant interrelationships. In conclusion, the formula to estimate FFM using the resistance and reactance values of BIA has been found to be useful in the present study.

Sociodemographic Disparities in Chemotherapy and Hematopoietic Cell Transplantation Utilization Among Acute Lymphoblastic Leukemia and Acute Myeloid Leukemia Patients

Introduction:Chemotherapy and hematopoietic cell transplantation (HCT) are cornerstones of therapy for acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). Identifying sociodemographic factors affecting utilization of chemotherapy and HCT may help improve outcomes for more patients with acute leukemia.Methods: Using the California Cancer Registry, we performed a retrospective population-based study of treatment administration in patients ≥15 years of age diagnosed with ALL (n=3,221) or AML (n=10,029) between 1/2003 and 12/2012. The effect of age, sex, race/ethnicity, marital status, neighborhood socioeconomic status (nSES), and distance from nearest transplant center on the receipt of no treatment, chemotherapy alone, or chemotherapy followed by HCT was assessed. Chemotherapy and HCT were common events ensuring that odds ratios for treatment would overestimate relative risk (RR). Log-binomial and negative binomial regression models did not converge so Poisson regression with robust confidence intervals was used to estimate crude and adjusted RR with 95 percent confidence interval limits (CIs). Model fitness assumption using Pearson’s chi-squared tests did not reveal over dispersion. Testing for multicollinearity showed no highly correlated covariates. Influence analysis did not identify influential observations or critical outliers. The Cochran-Armitage test for trend was used to assess changes in treatment utilization over time. Predictors were selected a priori based on published studies. Google maps API was used to compute the shortest driving distance between place of residence and nearest transplant centers. All statistical tests were 2-sided and conducted at a significance level of 0.05.Results: Patients <60 years of age comprised 75.5% of ALL and 31.5% of AML patients. Females represented 43% of ALL and 45% of AML patients. ALL represented 47.3% of acute leukemia cases in Hispanics versus 20.5%, 19.0% and 15.6% in Asian/other, non-Hispanic blacks, and non-Hispanic whites, respectively. Among ALL patients, 11%, 75% and 14% received no treatment, chemotherapy, or chemotherapy followed by HCT, respectively. For AML patients, 36% received no treatment while 53% and 11% were treated with chemotherapy or chemotherapy followed by HCT, respectively. HCT rates were highest in 40-59 year-old (yo) ALL patients (21.3%) and 15-39 yo AML patients (31.3%). Only 3.4% of ALL patients and 3.6% of AML patients over ≥60 yo underwent HCT. Covariate-adjusted findings showed a decreasing RR of chemotherapy with increasing age for ALL (trend p <0.001) and AML (trend p <0.001). Compared to 40-59 yos, those ≥60 years of age had reduced utilization of chemotherapy and HCT [ALL, RR 0.20 (95% CI=0.14-0.29); AML, RR 0.23 (95% CI=0.20-0.26)]. Overall, older acute leukemia patients showed increasing utilization of chemotherapy and HCT over the study period. For ALL patients ≥60 yo, chemotherapy utilization was stable (p=0.38) while HCT utilization increased from 5% in 2005 to 9% in 2012 (p=0.03). Among AML patients ≥60 yo, chemotherapy utilization increased from 39% in 2003 to 58% in 2012 (p<0.001) and HCT utilization from 5% in 2003 to 9% in 2012 (p<0.001). Relative to non-Hispanic whites, lower HCT utilization was observed in Hispanic white [ALL, RR=0.80 (95% CI =0.65-0.98); AML, RR=0.86 (95% CI =0.75-0.99)] and non-Hispanic black patients [ALL, RR=0.40 (95% CI =0.18-0.89); AML, RR=0.60 (95% CI =0.44-0.83)]. Compared to married patients, never married patients had a lower RR of receiving chemotherapy [ALL, RR=0.96 (95% CI=0.92-0.99); AML, RR=0.94 (95% CI=0.90-0.98)] or HCT [ALL, RR=0.58 (95% CI=0.47-0.71); AML, RR=0.80 (95% CI=0.70-0.90)]. Lower nSES quintiles predicted lower chemotherapy and HCT utilization for ALL and AML (Trend p <0.001).For ALL and AML, the lowest SES quintile had a lower RR of chemotherapy [ALL, RR= 0.95 (95% CI 0.90-0.99); AML, RR=0.89 (95% CI 0.84-0.94)] and HCT [ALL, RR=0.63 (95% CI 0.47-0.84); AML, RR=0.52 (95% CI 0.43-0.64)] compared to the highest nSES quintile. Distance from a transplant center had no impact on the receipt of chemotherapy or HCT.Conclusions: Older age, lower neighborhood SES, and being unmarried predicted lower utilization of both chemotherapy and HCT among ALL and AML patients. Addressing these disparities may increase utilization of known curative therapies and improve survival in underserved acute leukemia patients. DisclosuresNo relevant conflicts of interest to declare.

Cardiac Resynchronization Therapy Delivered Via a Multipolar Left Ventricular Lead is Associated with Reduced Mortality and Elimination of Phrenic Nerve Stimulation: Long-Term Follow-Up from a Multicenter Registry.

Lower Mortality and Eliminated PNS Associated with Quadripolar LeadsIntroductionCardiac resynchronization therapy (CRT) using quadripolar left ventricular (LV) leads provides more pacing vectors compared to bipolar leads. This may avoid phrenic nerve stimulation (PNS) and allow optimal lead placement to maximize biventricular pacing. However, a long‐term improvement in patient outcome has yet to be demonstrated.MethodsA total of 721 consecutive patients with conventional CRTD criteria implanted with quadripolar (n = 357) or bipolar (n = 364) LV leads were enrolled into a registry at 3 UK centers. Lead performance and mortality was analyzed over a 5‐year period.ResultsPatients receiving a quadripolar lead were of similar age and sex to those receiving a bipolar lead, although a lower proportion had ischemic heart disease (62.6% vs. 54.1%, P = 0.02). Both groups had similar rates of procedural success, although lead threshold, impedance, and procedural radiation dose were significantly lower in those receiving a quadripolar lead. PNS was more common in those with quadripolar leads (16.0% vs. 11.6%, P = 0.08), but was eliminated by switching pacing vector in all cases compared with 60% in the bipolar group (P < 0.001). Furthermore, LV lead displacement (1.7% vs. 4.6%, P = 0.03) and repositioning (2.0% vs. 5.2%, P = 0.03) occurred significantly less often in those with a quadripolar lead. All‐cause mortality was also significantly lower in the quadripolar compared to bipolar lead group in univariate and multivariate analysis (13.2% vs. 22.5%, P < 0.001).ConclusionsIn a large, multicenter experience, the use of quadripolar LV leads for CRT was associated with elimination of PNS and lower overall mortality. This has important implications for LV pacing lead choice.

Selected Trace Elements in Domestic Water Boreholes and Their Implications on Human Health, in Huruma Estate, Eldoret Municipality, Uasin-Gishu County, Kenya

Trace elements constitute less than 1% of the rocks in the crust (Stumm and Morgan, 1991). In the human body, they constitute less than 100 mg/kg (0.01%). These elements are released to the environment naturally by weathering and volcanic activities (Flint and skinner, 1997). It has been observed that trace elements are greatly absorbed and retained in the body when in liquid diet. This phenomenon also influences the risk to human health, especially of infants and children whose immature digestive system further promote absorption of toxic heavy metals. The study was based on the analysis of domestic borehole water supplies in Huruma estate of Eldoret Municipality for selected trace elements and their implications on human health. The boreholes were systematically selected for sampling points and trace elements, Cr, Cu and Se analyzed using AAS. Statistical analysis for mean, standard deviation and confidence interval limits was done using SPSS. The statistical t-test was used to test for significance differences at (p = 0.05). The graphs were drawn using the Microsoft Excel package. The resulting data obtained from analysis were compared with WHO data for drinking water. In the study, the mean values of the following parameters were as follows: Chromium 17.9 μg/L, Copper 563 μg/L and Selenium 22.7 μg/L. There was a significant difference at 5% level of significance (p = 0.000) in all the parameter values among the sampling points in Huruma estate. The above mean values were far below the WHO recommended limits for drinking water. It was concluded that the borehole water from Huruma was fit for drinking and therefore could not cause cancer and cardiovascular diseases. However, borehole water should be used if other water sources (tap water etc.) were not available. All the industries near Huruma estate should carefully analyze and regularly monitor their liquid waste effluents to ensure that no harmful discharges get into the soil.

Weigh-in-Motion Data Quality Assurance Based on 3-S2 Steering Axle Load Analysis

An innovative method is offered for conducting the quality assurance of weigh-in-motion (WIM) data by analyzing the variation in the measurements of five-axle semitrailer (3-S2) truck steering-axle loads. Confidence-interval limits for those measurements are established on the basis of their historic mean static loads adjusted for the effect of air resistance and their combined variation from two sources, the variation within a fleet of 3-S2 trucks and the variation due to axle dynamics at a WIM site. The first variation was determined by analyzing historic 3-S2 load data obtained by FHWA using static scales. The second variation was established through dynamic vehicle simulations of a “typical” 3-S2 truck using vehicle model VESYM and the roughness profile at a particular WIM site. The method was tested with data from four WIM systems in the state of Washington, two bending-plate systems and two piezoelectric systems. The proposed method resulted in clear indications of the performance of the scale versus time by the number of confidence interval violations observed.