UCLA Department of Statistics

2010 Archives

Susan Love Foundation

Our consulting team worked with the Dr. Susan Love Research Foundation on two projects. The first was to model the levels of four hormones and residual proteins in the breast ductile lavage fluid of healthy women. Methods used include nested models, data transformation, simulating missing data and intraclass correlation (ICC). The second was to explore chemical levels collected of patients over several hours after exposure to different medications, comparing levels between ductile lavage, blood and nipple aspirative fluid (NAF) with plots. Methods include ggplot, time series and kernel smoothing estimation.

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Posted on Dec 07, 2010

Neonatal Candidiasis Risk Factors

Methodology: Logistic regression
Client affiliation: UCLA Medical Center, Pediatric Infectious Diseases Clinic

Medical researchers are studying the effect of treatment delay and various other factors in neonatal candidiasis. We conducted logistic regression analysis to determine how treatment delay and other various factors affect the likelihood of survival of the subject. We also investigated the relationship between these factors and the outcome when patients whose only culture was from a respiratory source were excluded from the analysis.


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Posted on Nov 15, 2010

CVCB Antimicrobial Lock Therapy Study

Methodology: Pearson’s chi-square test and generalized linear models
Client affiliation: Stamford Hospital, Department of Infectious Diseases and Microbiology

Episodes of central venous catheter-related bacteremia (CVCB) have become common events in patients with long-term indwelling central venous catheter use. Since no standardized treatment of CVCB exists, novel approaches have been used to salvage infected catheters where vascular access is limited. Use of antibiotic lock solutions (e.g., a solution of an antibiotic agent and heparin) to fill catheter lumens between treatments (antibiotic-lock treatment, ALT) has been shown to prevent CVCB and may be useful for treatment of already-infected catheters. In this report we analyze the success of ALT in preventing CVCB.


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Posted on Feb 24, 2010

Type 2 Diabetes Mellitus and Melatonin Levels

Methodology: Power analysis
Client affiliation: UCLA Medical Center, Division of Endocrinology

We provided medical researchers planning a study investigating the melatonin levels of patients with type 2 diabetes mellitus with a power analysis in order to help them determine the sample size required for certain effect size and power combinations.


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Posted on Feb 24, 2010

Assersion of comprehensive approach to dermatology

Methodology: Multivariate regression, Bayesian statistics
Client affiliation: UCLA Medical Center, Division of Dermatology

Study was conducted to see if comprehensive approach to dermatology is more effective than treating the skin condition alone with topicasls. Subjects were divided into the treatment and control group and 10 minute educational intervention was given to the treatment group along with topical corticosteroids and just topical corticosteroids and no intervention to the control group.
Several kinds of measurement was taken before and after the intervention for the treatment group and control group of which 4 are of primary interest; phase angle, basal metabolic rate, intracellular water, and free fat mass. Result showed treatment effect in the expected direction, yet because of the small sample size result showed that treatment was not statistically significant.


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Posted on Nov 15, 2010

Carpinteria Childbearing Survey

Methodology: Exploratory data analysis, data visualization
Client affiliation: First 5 Santa Barbara County Early Care and Education Division

A voluntary survey on women in Carpinteria about their childbirth experience was conducted to help design a program to benefit pregnant women and new moms. This report summarizes the results of this survey.


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Posted on Feb 02, 2010

Thyroid Cancer and Iodine Levels

Methodology: Power analysis
Client affiliation: UCLA Medical Center, Division of Endocrinology

We provided medical researchers planning a study investigating iodine levels of thyroid cancer patients with a power analysis in order to help them determine the sample size required for certain effect size and power combinations.


Click here for completed report.

Posted on Feb 02, 2010

Surgery preference of orthopedic surgeons based on X-rays

Methodology: Generalized linear mixed effects models
Client affiliation: UCLA Medical Center, Department of Orthopaedic Surgery

For this project we are working with orthopedic surgeons from UCLA Medical Center who conducted an online survey that 700+ orthopedic surgeons responded to. In this survey the surgeons were asked about their training (3 categories), their practice (academic vs. private) and what percentage of their practice involves treatment of pediatric patients (4 categories). Then they were shown a series of 10 X-ray images and asked whether they would choose to operate on the patient based on the X-ray. Multi-level modeling is used to examine if there are significant differences in rate of surgery preference based on training, practice and percentage of treatment of pediatric patients the surgeon’s practice involves.


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Posted on Feb 02, 2010