44 research outputs found
Hospital readmission and healthcare utilization following sepsis in community settings
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108012/1/jhm2197.pd
Prediction of recurrent Clostridium difficile infection using comprehensive electronic medical records in an integrated healthcare delivery system
BACKGROUNDPredicting recurrentClostridium difficileinfection (rCDI) remains difficult. METHODS. We employed a retrospective cohort design. Granular electronic medical record (EMR) data had been collected from patients hospitalized at 21 Kaiser Permanente Northern California hospitals. The derivation dataset (2007–2013) included data from 9,386 patients who experienced incident CDI (iCDI) and 1,311 who experienced their first CDI recurrences (rCDI). The validation dataset (2014) included data from 1,865 patients who experienced incident CDI and 144 who experienced rCDI. Using multiple techniques, including machine learning, we evaluated more than 150 potential predictors. Our final analyses evaluated 3 models with varying degrees of complexity and 1 previously published model.RESULTSDespite having a large multicenter cohort and access to granular EMR data (eg, vital signs, and laboratory test results), none of the models discriminated well (c statistics, 0.591–0.605), had good calibration, or had good explanatory power.CONCLUSIONSOur ability to predict rCDI remains limited. Given currently available EMR technology, improvements in prediction will require incorporating new variables because currently available data elements lack adequate explanatory power.Infect Control Hosp Epidemiol2017;38:1196–1203</jats:sec
A new multivariate measurement error model with zero-inflated dietary data, and its application to dietary assessment
In the United States the preferred method of obtaining dietary intake data is
the 24-hour dietary recall, yet the measure of most interest is usual or
long-term average daily intake, which is impossible to measure. Thus, usual
dietary intake is assessed with considerable measurement error. Also, diet
represents numerous foods, nutrients and other components, each of which have
distinctive attributes. Sometimes, it is useful to examine intake of these
components separately, but increasingly nutritionists are interested in
exploring them collectively to capture overall dietary patterns. Consumption of
these components varies widely: some are consumed daily by almost everyone on
every day, while others are episodically consumed so that 24-hour recall data
are zero-inflated. In addition, they are often correlated with each other.
Finally, it is often preferable to analyze the amount of a dietary component
relative to the amount of energy (calories) in a diet because dietary
recommendations often vary with energy level. The quest to understand overall
dietary patterns of usual intake has to this point reached a standstill. There
are no statistical methods or models available to model such complex
multivariate data with its measurement error and zero inflation. This paper
proposes the first such model, and it proposes the first workable solution to
fit such a model. After describing the model, we use survey-weighted MCMC
computations to fit the model, with uncertainty estimation coming from balanced
repeated replication.Comment: Published in at http://dx.doi.org/10.1214/10-AOAS446 the Annals of
Applied Statistics (http://www.imstat.org/aoas/) by the Institute of
Mathematical Statistics (http://www.imstat.org
Evaluation of the VACUTAINER PPT Plasma Preparation Tube for Use with the Bayer VERSANT Assay for Quantification of Human Immunodeficiency Virus Type 1 RNA
Separation and storage of plasma within 2 h of phlebotomy is required for the VACUTAINER PPT Plasma Preparation Tube (PPT) versus 4 h for the predecessor VACUTAINER EDTA tube for human immunodeficiency virus type 1 (HIV-1) viral load (HIVL) testing by the VERSANT HIV-1 RNA 3.0 assay (branched DNA). The 2-h limit for PPT imposes time constraints for handling and transporting to the testing laboratory. This study compares HIVL reproducibility from matched blood in EDTA tubes and PPTs and between PPT pairs following processing within 4 h of phlebotomy, stability of plasma HIV-1 RNA at 24- and 72-h room temperature storage in the tube, and comparative labor and supply requirements. Blood from 159 patients was collected in paired tubes (EDTA/PPT or PPT/PPT): 86 paired EDTA tubes and PPTs were processed 4 h following phlebotomy and their HIVLs were compared, 42 paired PPT/PPT pairs were analyzed for intertube HIVL reproducibility, and 31 PPT/PPT pairs were analyzed for HIV-1 RNA stability by HIVL. Labor and supply requirements were compared between PPT and EDTA tubes. PPTs produce results equivalent to standard EDTA tube results when processed 4 h after phlebotomy. PPT intertube analyte results are reproducible. An average decrease of 13% and 37% in HIVL was observed in PPT plasma after 24 and 72 h of room temperature storage, respectively; thus, plasma can be stored at room temperature up to 24 h in the original tube. PPTs offer labor and supply savings over EDTA tubes
Construction of trend-resistant factorial designs
The problem of constructing trend-resistant factorial designs is discussed. Suppose a factorial experiment is to be run in a time sequence with one observation taken at a time. Then the experimenter has to decide in which order to observe the treatment combinations. A common practice is to randomize. However, sometimes randomization may lead to an undesirable ordering, and a systematic run order may be preferred. Attention is focused on the construction of systematic run orders of factorial designs in which the estimates of important factorial effects are orthogonal to some polynomial trends. Some recent work on this subject is unified and extended
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Frequency, duration and predictors of bronchiolitis episodes of care among infants [greater than or equal to]32 weeks gestation in a large integrated healthcare system: a retrospective cohort study
AbstractBackgroundBronchiolitis is common in the first two years of life and is the most frequent cause of hospitalization in this age group. No previous studies have used an episode-of-care analysis to describe the frequency, duration, and predictors of bronchiolitis episodes of care during the first two years.MethodsWe conducted a retrospective cohort study of 123,264 infants ≥32 weeks gestation born at 6 Northern California Kaiser Permanente hospitals between 1996 and 2002. We used electronic medical records to concatenate hospital, emergency department and outpatient health care encounters for bronchiolitis into discrete episodes of care. We used descriptive statistics to report frequency and duration of bronchiolitis episodes and used logistic regression to assess the effect of gestational age and other clinical and demographic predictors on the outcome of bronchiolitis episodes.ResultsAmong all infants, the rate of bronchiolitis episodes was 162 per 1000 children during the first 2 years of life; approximately 40% required >1 day of medical attention with a mean duration of 7.0 ± 5.9 days. Prematurity was associated with increased risk of bronchiolitis episodes and longer duration. Bronchiolitis episodes rates per 1000 infants were 246 for 32–33 weeks gestational age, 204 for 34–36 weeks, and 148–178 for >36 weeks. Male gender, African-American and Hispanic race/ethnicity, and parental history of asthma were associated with an increased risk of having a bronchiolitis episode and/or longer duration.ConclusionsBronchiolitis episodes of care are frequent during the first two years of life and the duration ranges from 1 to 27 days. Prematurity was associated with more frequent and longer duration of bronchiolitis episodes of care, which may reflect illness severity and/or perceived vulnerability
Frequency, duration and predictors of bronchiolitis episodes of care among infants ≥32 weeks gestation in a large integrated healthcare system: a retrospective cohort study
Abstract Background Bronchiolitis is common in the first two years of life and is the most frequent cause of hospitalization in this age group. No previous studies have used an episode-of-care analysis to describe the frequency, duration, and predictors of bronchiolitis episodes of care during the first two years. Methods We conducted a retrospective cohort study of 123,264 infants ≥32 weeks gestation born at 6 Northern California Kaiser Permanente hospitals between 1996 and 2002. We used electronic medical records to concatenate hospital, emergency department and outpatient health care encounters for bronchiolitis into discrete episodes of care. We used descriptive statistics to report frequency and duration of bronchiolitis episodes and used logistic regression to assess the effect of gestational age and other clinical and demographic predictors on the outcome of bronchiolitis episodes. Results Among all infants, the rate of bronchiolitis episodes was 162 per 1000 children during the first 2 years of life; approximately 40% required >1 day of medical attention with a mean duration of 7.0 ± 5.9 days. Prematurity was associated with increased risk of bronchiolitis episodes and longer duration. Bronchiolitis episodes rates per 1000 infants were 246 for 32–33 weeks gestational age, 204 for 34–36 weeks, and 148–178 for >36 weeks. Male gender, African-American and Hispanic race/ethnicity, and parental history of asthma were associated with an increased risk of having a bronchiolitis episode and/or longer duration. Conclusions Bronchiolitis episodes of care are frequent during the first two years of life and the duration ranges from 1 to 27 days. Prematurity was associated with more frequent and longer duration of bronchiolitis episodes of care, which may reflect illness severity and/or perceived vulnerability.</p