157 research outputs found
Maximum Agreement Linear Prediction via the Concordance Correlation Coefficient
This paper examines distributional properties and predictive performance of
the estimated maximum agreement linear predictor (MALP) introduced in Bottai,
Kim, Lieberman, Luta, and Pena (2022) paper in The American Statistician, which
is the linear predictor maximizing Lin's concordance correlation coefficient
(CCC) between the predictor and the predictand. It is compared and contrasted,
theoretically and through computer experiments, with the estimated
least-squares linear predictor (LSLP). Finite-sample and asymptotic properties
are obtained, and confidence intervals are also presented. The predictors are
illustrated using two real data sets: an eye data set and a bodyfat data set.
The results indicate that the estimated MALP is a viable alternative to the
estimated LSLP if one desires a predictor whose predicted values possess higher
agreement with the predictand values, as measured by the CCC
Routine use of completion imaging after infrainguinal bypass is not associated with higher bypass graft patency
BackgroundSignificant variability exists in completion imaging (CIM) after infrainguinal lower extremity bypass (LEB). We evaluated the use of CIM and compared graft patency in patients treated by surgeons who performed routine CIM vs those who performed selective CIM.MethodsWe reviewed the Vascular Study Group of New England database (2003-2010) and assessed the use of CIM (angiography or duplex ultrasound) among patients undergoing LEB. The surgeon-specific CIM strategy was categorized as routine (â„80% of LEBs) vs selective (<80% of LEBs). Exclusion criteria included acute limb ischemia, bilateral procedures, and surgeon volume <10 cases per study period. Primary graft patency at discharge and at 1 year was analyzed on the basis of CIM use and surgeon-specific CIM strategy. Multivariable analyses were performed using Poisson regression.ResultsAmong 2032 LEB procedures performed by 48 surgeons, CIM was used in 1368 cases (67.3%). CIM was performed in 72% of autogenous LEBs and 52% of prosthetic grafts. Dialysis (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.6; P = .01), elective LEB (OR, 2.6; 95% CI, 1.4-4.8; P = .002), great saphenous vein conduit (OR, 2.0; 95% CI, 1.6-2.5; P < .001), and tibial or pedal target artery (OR, 1.8; 95% CI, 1.4-2.3; P < .001) were associated with CIM use. In multivariate models, CIM was not associated with improved primary graft patency at discharge (OR, 1.1; 95% CI, 0.7-1.7; P = .64) or at 1 year (OR, 0.9; 95% CI, 0.7-1.2; P = .47). Sixteen surgeons (33%) were routine users and 32 (67%) were selective users of CIM. Among patients of routine vs selective CIM users, primary graft patency at discharge and at 1 year was 96% vs 94% (P = .21) and 68% vs 72% (P = .09), respectively. In multivariate analysis, routine or selective CIM strategy was not associated with improved discharge (rate ratio, 0.8; 95% CI, 0.6-1.1; P = .31) or 1-year (rate ratio, 1.1; 95% CI, 0.9-1.2; P = .56) graft patency.ConclusionsIn our observational cohort, CIM does not improve short-term and 1-year bypass graft patency in infrainguinal LEB. The surgeon-specific strategy of selective CIM after LEB has outcomes comparable to those of routine CIM
N-Terminal ProâB-Type Natriuretic Peptide in the Emergency Department: The ICON-RELOADED Study
Background
Contemporary reconsideration of diagnostic N-terminal proâB-type natriuretic peptide (NT-proBNP) cutoffs for diagnosis of heart failure (HF) is needed.
Objectives
This study sought to evaluate the diagnostic performance of NT-proBNP for acute HF in patients with dyspnea in the emergency department (ED) setting.
Methods
Dyspneic patients presenting to 19 EDs in North America were enrolled and had blood drawn for subsequent NT-proBNP measurement. Primary endpoints were positive predictive values of age-stratified cutoffs (450, 900, and 1,800 pg/ml) for diagnosis of acute HF and negative predictive value of the rule-out cutoff to exclude acute HF. Secondary endpoints included sensitivity, specificity, and positive (+) and negative (â) likelihood ratios (LRs) for acute HF.
Results
Of 1,461 subjects, 277 (19%) were adjudicated as having acute HF. The area under the receiver-operating characteristic curve for diagnosis of acute HF was 0.91 (95% confidence interval [CI]: 0.90 to 0.93; p < 0.001). Sensitivity for age stratified cutoffs of 450, 900, and 1,800 pg/ml was 85.7%, 79.3%, and 75.9%, respectively; specificity was 93.9%, 84.0%, and 75.0%, respectively. Positive predictive values were 53.6%, 58.4%, and 62.0%, respectively. Overall LR+ across age-dependent cutoffs was 5.99 (95% CI: 5.05 to 6.93); individual LR+ for age-dependent cutoffs was 14.08, 4.95, and 3.03, respectively. The sensitivity and negative predictive value for the rule-out cutoff of 300 pg/ml were 93.9% and 98.0%, respectively; LRâ was 0.09 (95% CI: 0.05 to 0.13).
Conclusions
In acutely dyspneic patients seen in the ED setting, age-stratified NT-proBNP cutpoints may aid in the diagnosis of acute HF. An NT-proBNP <300 pg/ml strongly excludes the presence of acute HF
Temporal order of RNase IIIb and loss-of-function mutations during development determines phenotype in DICER1 syndrome: a unique variant of the two-hit tumor suppression model [v1; ref status: approved with reservations 1, http://f1000r.es/5l9]
Pleuropulmonary blastoma (PPB) is the most frequent pediatric lung tumor and often the first indication of a pleiotropic cancer predisposition, DICER1 syndrome, comprising a range of other individually rare, benign and malignant tumors of childhood and early adulthood. The genetics of DICER1-associated tumorigenesis are unusual in that tumors typically bear neomorphic missense mutations at one of five specific âhotspotâ codons within the RNase IIIb domain of DICER 1, combined with complete loss of function (LOF) in the other allele. We analyzed a cohort of 124 PPB children for predisposing DICER1 mutations and sought correlations with clinical phenotypes. Over 70% have inherited or de novo germline LOF mutations, most of which truncate the DICER1 open reading frame. We identified a minority of patients who have no germline mutation, but are instead mosaic for predisposing DICER1 mutations. Mosaicism for RNase IIIb domain hotspot mutations defines a special category of DICER1 syndrome patients, clinically distinguished from those with germline or mosaic LOF mutations by earlier onsets and numerous discrete foci of neoplastic disease involving multiple syndromic organ sites. A final category of patients lack predisposing germline or mosaic mutations and have disease limited to a single PPB tumor bearing tumor-specific RNase IIIb and LOF mutations. We propose that acquisition of a neomorphic RNase IIIb domain mutation is the rate limiting event in DICER1-associated tumorigenesis, and that distinct clinical phenotypes associated with mutational categories reflect the temporal order in which LOF and RNase IIIb domain mutations are acquired during development
Outpatient prescription practices in patients with atrial fibrillation (from the NCDR PINNACLE registry)
This study sought to evaluate inappropriate prescribing practices in an atrial fibrillation (AF) population, as outlined by the 2016 ACC/AHA Clinical Performance and Quality Measures for Adults with Atrial Fibrillation or Atrial Flutter document. The 2016 AF quality measures document specified medications to avoid in certain AF populations, including aspirin and anticoagulant combination therapy in patients without cardiovascular disease, and non-dihydropyridine calcium channel blockers in patients with reduced ejection fraction. Using data from the NCDR PINNACLE registry, a national outpatient cardiology practice registry, we assessed rates of inappropriate prescription of two types of medications among AF outpatients from 5/1/2008-5/1/2016. Overall rates of inappropriate prescription and variation by practice were calculated. Patient and practice factors associated with inappropriate prescription were assessed in adjusted analyses. A total of 107,759 of 658,250 (16.4%) patients without cardiovascular disease were inappropriately prescribed an antiplatelet and anticoagulant together, and 5,731 of 150,079 (3.8%) patients with reduced ejection fraction were inappropriately prescribed a non-dihydropyridine calcium channel blocker. Overall, 14.8% of AF patients were prescribed medications that were not recommended. Both patient and practice factors were associated with inappropriate prescribing, and the adjusted practice-level median odds ratio for inappropriate prescription was 1.70 (95% CI: 1.61-1.82), indicating a 70% likelihood that 2 random practices would treat identical AF patients differently. In a large registry of AF patients treated in cardiology practices, overall rates of inappropriate prescription practices, as defined by the 2016 AF quality measures, were relatively low, but significant practice variation was present
Caregiving, Metabolic Syndrome Indicators, and 1-year Decline in Walking Speed: Results of Caregiver-SOF
BACKGROUND
Chronic stress may lead to health decline through metabolic syndrome. Thus, persons in stressful caregiving situations who also have more indicators of metabolic syndrome may experience more decline than other caregivers or noncaregivers.
METHODS
The sample included 921 women (338 caregivers and 583 noncaregivers) from the Caregiver-Study of Osteoporotic Fractures study. Participants had home-based baseline and 1-year follow-up interviews between 1999 and 2003. At baseline, caregivers were categorized as long term (Âł4 years) versus short term (<4 years), and caring for someone with Alzheimer's disease/dementia or not. A metabolic risk composite score was the sum of four indicators: body mass index Âł30, and diagnosis or using medications for hypertension, diabetes, or high cholesterol. Walking speed (m/second) was measured at both interviews.
RESULTS
Walking speed declined for the total
sample (adjusted mean = â0.005 m/second, ±0.16) over an average of 1.04 years (±0.16). Overall, caregiving was not associated with decline. Increasing metabolic risk score was associated with greater decline for the total sample and long-term and dementia caregivers, but not other caregivers or noncaregivers. Metabolic risk score modified the adjusted associations between years of caregiving and dementia caregiving with walking speed decline (p values for interaction terms were 0.039 and 0.057, respectively). The biggest declines were in long-term caregivers and dementia caregivers who also had 3â4 metabolic indicators (â0.10 m/second and â0.155 m/second, respectively).
CONCLUSIONS
Walking speed declined the most among older women who had both stressful caregiving situations and more metabolic syndrome indicators, suggesting these caregiver subgroups may have increased risk of health decline.AG18037, AG05407, AR35582, AG05394, AR35584, and AR3558
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