UCLA Department of Statistics

Publications

Reports

SCC-TR-2010-0005: Neonatal Candidiasis Risk Factors

Mine Çetinkaya


Medical researchers at UCLA Medical Center Pediatric Infectious Diseases Clinic 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.

SCC-TR-2010-0004: CVCB Antimicrobial Lock Therapy Study

Mine Çetinkaya, Colin Rundel


Medical researchers at Department of Infectious Diseases and Microbiology at the Stamford Hospital in Stamford, CT are studying episodes of central venous catheter-related bacteremia (CVCB) that 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.

SCC-TR-2010-0003: Type 2 Diabetes Mellitus and Melatonin Levels

Mine Çetinkaya


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

SCC-TR-2010-0002: Assersion of comprehensive approach to dermatology

Masanao Yajima


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 measurements were 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.

SCC-TR-2010-0001: Carpinteria Childbearing Survey

Mine Çetinkaya


First 5 Santa Barbara County Early Care and Education Division conducted a voluntary survey on women in Carpinteria about their childbirth experience to help us design a program to benefit pregnant women and new moms. This report summarizes the results of this survey. First 5 Santa Barbara County Early Care and Education Division conducted a voluntary survey on women in Carpinteria about their childbirth experience to help us design a program to benefit pregnant women and new moms. This report summarizes the results of this survey.

SCC-TR-2009-0002: Surgery Preference of Orthopedic Surgeons Based on X-rays

Brigid Wilson, Mine Çetinkaya


Medical researchers at the UCLA Department of Orthopedics have conducted an online survey on surgeons. The survey collected information on the practice, training and what percentage of their practice involves treatment of pediatric patients and asked them whether or not they would recommend surgery based on a series of x-rays. We provided them with a multi-level analysis on whether or not there were significant differences between surgery preference rates based on the variables described above.

SCC-TR-2009-0001: Thyroid Cancer and Iodine Levels

Brigid Wilson, Mine Çetinkaya


We provided medical researchers from UCLA Medical Center, Division of Endocrinology who were 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.

Theses

Statistical Analysis of Gasoline and Diesel Loss Rates at Retailers

Xiaofei Yan

It has been known in petroleum industry that fuel expands when the temperature increases and contracts when the temperature decreases. Gasoline has 1% volumetric change for every 15 degree F change, and diesel has 0:6% volumetric change for every 15 degree F change. There have been a 60 degree Fahrenheit standard for temperature correction of bulk deliveries of petroleum products. However, as the temperatures the fuel was sold at were above 60 degree F at many states, it is said every year overall 670 million additional gallons of gasoline and 90 million additional gallons of diesel were consumed in U.S. because of the fuel expansion. Laws and rules about installation temperature-corrected kits at dispensers are already on the way in many U.S. states. However, besides the interests of the individual consumers, the retailers who purchase bulks of fuel from wholesaler are also experiencing the loss caused by fuel expansion. For the sake of fairness, it is necessary to find evidence of fuel loss for the retailers if there are litigations in the future. The purpose of this project is to determine whether retailers were experiencing constant fuel loss, and what environmental elements might influence on such fuel loss. It is also interesting to see whether the pattern of the fuel loss can be fitted by any models.