UCLA Department of Statistics

2009 Archives

Quality of Reproductive Health Services to Limited English Proficient Patients

Methodology: Generalized linear mixed effects models
Client affiliation: Bixby Center for Global Reproductive Health

This study explores the association between language discordance and key indicators of reproductive health care quality. We seek to test the hypothesis that patients seen by a bilingual provider, on average, receive higher quality services than patients who receive reproductive health services with the help of an interpreter. In order to do so we have analyzed patient care indicator data using generalized linear mixed models with nested structure.

Click here for completed report.

Posted on Mar 10, 2009

Executive Compensation

Methodology: Multinomial logistic regression, generalized linear mixed models, linear regression with random intercept
Client affiliation: Boston University School of Law

Analyzing data from fortune 1500 companies over two recent years for the five top executives within each company. The data includes variables both at the individual executive level and at the company level. The outcome of interest is the proportion of compensation in stock and stock options composed of stock options. We will merge data from two financial databases and fit an appropriate multilevel/repeated measures model for this data.

Click here for completed report.

Posted on Mar 10, 2009

Identification of Optimal Buy and Sell Periods

Methodology: Financial data simulation and forecasting
Client affiliation: Fried Asset Management, Inc.

In this stocks project, we examined a client’s stock portfolio over a decade. We looked at the distribution of closing prices among the holdings and calculated the returns that would be seen with various combinations of hard sell points and trailing stop losses. Moving averages over 50 and 200 days were analyzed in the hopes of identifying optimal buy and sell periods based on these statistics.

Posted on Mar 05, 2009

Surgical Drainage Meta-Analysis

Methodology: Meta-analysis
Client affiliation: Aesthetic and Plastic Surgery Institute, University of California, Irvine

Surgeons routinely use prophylactic drainage after surgery however this practice is often disliked by patients and the benefits are not always clear. Recently surgeons have been explicitly testing the value of drainage in specific surgical proceedures. The objective of this project is to determine the evidence-based value of prophylactic drainage in surgeries where drainage is above the fascia and below subcutaneous tissue. We are performing a meta-analysis of existing studies involving these kinds of drainage to characterize the drain effectiveness using a random-effects model considering possible outcomes such as hematomas, abscesses, seromas and or infections.

Click here for completed report.

Posted on Mar 04, 2009

Application of Constrained PCA to Understanding Brands

Methodology: Constrained PCA
Client affiliation: A marketing research firm in San Diego

The objective of this project is to develop an algorithm for Constained PCA that will be used in to learn about positioning as well as weaknesses of brands to be used by a marketing research firm.

As a final product R code was delivered to the client.

Posted on Mar 04, 2009

Evolution of Channel Islands Population

Methodology: Homogeneity analysis using HOMALS in R
Client affiliation: California State University – Los Angeles, Department of Physical Anthropology

There has been population replacement during the prehistoric times on the Channel Islands. Before the Spanish came, there were two different Indian populations: one in the North and one in the South of the Channel Island, confirmed by cranial measurements and Mitochondrial DNA (MDNA). The Northern population (is closer to Santa Barbara) are the Chumash Indians and the Southern one, the Ituaztecan. The Ituaztecan spread to Central America and pushed out the Chumash. (We do not know around what time this happened.) Using MDNA, the client has 6 reliable skull classifications (from 3 different islands), belonging to either of the two groups. With this information, he would like to be able to classify about 100 other individuals, based on their cranial measurements, taking location into account.

Click here for completed report.

Posted on Mar 04, 2009

Fuel Loss

Methodology: Exploratory data analysis, non-parametric regression
Client affiliation: United Oil

In this project we investigate transportation fuel loss among retailers and what environmental elements or business practices might influence such fuel loss. The transportation fuels industry has monitored the disappearance of a small percentage of fuel throughout retailers in Santa Barbara, Los Angeles, Orange County, and San Diego since 2001, and we will investigate potential causes of this loss to help mitigate future losses.

Posted on Mar 04, 2009