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Beyond the Numbers

By Gregg Sangillo

American University statistics professor Elizabeth Malloy is part of a team that will study 35 workplaces across industries such as automotive, cabinetry, electronics, and glass and window manufacturing.

AU statistics professor Elizabeth Malloy is part of a team that will study 35 workplaces across industries such as automotive, cabinetry, electronics, and glass and window manufacturing.

If you mention statistics to most people, they usually think number crunching and math. Yet for American University professor Elizabeth Malloy, statistics can be a springboard to understanding multiple academic disciplines and addressing real-world problems.

Malloy's new research will delve into the world of ergonomics, a pertinent field of study in today's economy. She'll be part of a team examining potential workplace exposures to Carpal Tunnel Syndrome (CTS), Lateral Epicondylitis (more commonly known as "tennis elbow"), and Medial Epicondylitis (sometimes called "golfer's elbow").

Researching the Workplace

With funding from the National Institute for Occupational Safety and Health, three groups—the University of Wisconsin-Milwaukee, the University of Utah, and Washington State Department of Labor &Industries—will study the relationships between physical job demands and upper limb injuries. The groups will pool data from 35 U.S. workplaces across a variety of industries, such as automotive, cabinetry, electronics, and glass and window manufacturing. Through video or direct measurement in the field, researchers will observe workers' biomechanical stressors such as hand activity level and peak force on the job. Then, researchers will ascertain if there is an association between workplace physical stressors and the prevalence of Carpal Tunnel, and tennis or golf elbow.

Malloy, who is part of the Wisconsin team, will provide statistical analysis to model and summarize the relationships between workplace exposure and incidents of upper limb injuries. "It literally could be something simple like, 'Oh, the more you're exposed, the higher your risk.' Very rarely is it ever something so simple," explains Malloy, a professor of mathematics and statistics in the College of Arts and Sciences. "Where I come in is using these modeling methods which allow for more flexible fitting of nonlinear relationships."

The research project is expected to take three years. The conclusions should prove valuable for employers looking to enhance workplace safety and public health agencies steering injury prevention programs.

There are implications for the economy: The Bureau of Labor Statistics estimated more than 8,600 Carpal Tunnel cases in 2012, with 30 days of lost work per person. The problem is compounded by lost wages, workers' compensation and health care costs.

Challenges and Outliers

One research challenge is isolating for non-work factors that might lead to these injuries. A person could have contracted tennis elbow by, well, playing tennis. There are also health-related problems sometimes associated with Carpal Tunnel Syndrome, including arthritis, diabetes, smoking, and thyroid disease. But researchers can't possibly control for every potential contributing factor.

"This can show if there is an association demonstrated. This type of study does not prove, though, that this workplace exposure is causing it. This is an observational study," she says.

Potentially skewing the numbers is a process of self-selection, labeled Healthy Worker Survivor Effect. "What happens is if you're susceptible at a lower exposure, then you quit working and quit accumulating exposures," she explains.Conversely, she says, some workers keep accumulating exposures but don't show symptoms of injury.

The Joy of Stats

Carpal Tunnel Syndrome isn't an obvious subject for a stats professor, but she's not wading into entirely unfamiliar terrain. "Part of my post-doc had been working with someone who looked at health outcomes in an occupational setting, and this is just a natural extension of that," Malloy says. Malloy is even dealing with her own case of tennis elbow, which she got doing home repair work.

Malloy's research has offered her an entrée into a broad array of intellectual pursuits. Her interdisciplinary experience, she points out, enables her to work with both stat and non-stat focused students. "Any statistician will tell you that one of the exciting aspects of it is its applicability in so many areas. So on campus, I've worked with a biology professor, I've worked with two psychology professors, I've worked with education professors," she says. "That's really the joy of being a statistician."