The so-called “secondary tasks” that many professionals are expected to attend to at work can become big problems when ignored over time — think about a trucker constantly forgetting to obey the speed limit, even if only by a few miles per hour. But new Wharton research shows for the first time that those little things can begin to slip through the cracks due to fatigue that develops even within a single work day. In some cases, that drop-off can cost tens of thousands of lives and cost billions of dollars a year.

Wharton operations and information management professor Katherine L. Milkman and Wharton Ph.D. student Hengchen Dai co-authored “The Impact of Time at Work and Time off from Work on Rule Compliance: The Case of Hand Hygiene in Healthcare.” The paper, also co-authored by David A. Hofmann and Bradley R. Staats at the Kenan-Flagler Business School at the University of North Carolina Chapel Hill, shows that health care workers’ already low compliance rates with hand cleaning mandates decline precipitously over the course of a typical work shift.

Maintaining hand hygiene among health care workers has been widely accepted as one of the easiest ways to reduce patient infections, which affect one in every 20 hospitalized patients and, according to the U.S. Centers for Disease Control and Prevention and the World Health Organization, are one contributing factor to the estimated 100,000 health care-related deaths in the United States each year. Nevertheless, compliance with hand sanitizing standards has been found to be below 50% in most settings.

In the workplace, primary tasks are considered those that are most directly tied to production. Complying with professional standards like hand washing is perceived as a secondary task — even though it is vital, the researchers note. Previous studies about compliance with secondary tasks linked rigorous job demands with declines in compliance over long periods of time.

Other research shows that, when faced with multiple, often conflicting, goals and high job demands, employees prioritize performance on their primary tasks and focus less on their secondary duties as their brain power is rerouted to their main objectives.

“When people end their shift, the more worn out they are, the more they need a break and the bigger the benefits of the break are.” –Katherine Milkman

As employees tire, the authors write, “past research has shown that [they] exhibit selective impairment on low-priority task components … such as the neglect of subsidiary activities and narrowing of attention.”

But Milkman and her co-authors wanted to use those findings and study the effects of fatigue on secondary task compliance within a single work shift. They had two primary predictions: compliance with secondary tasks would decrease over the course of a work day, and breaks between work shifts would help workers increase their compliance.

The Benefits of a Break

Luckily, Milkman says the researchers had what she calls an “incredible” data set to work with: years of observations of 4,157 caregivers working in 35 different hospitals. These workers had more than 13.7 million hand hygiene opportunities stretching over more than two years. The data came from Proventix, a company that focuses on helping health care workers improve their hand hygiene.

To track compliance rates, Proventix uses radio frequency identification (RFID) technology and communication units attached to hand soap and sanitizer dispensers to monitor hygiene activity by health care workers. The RFID badges that caregivers wear track the location and behavior of the caregivers, and the communication units allow Proventix to monitor whether or not hands are cleaned when workers enter and leave a patient’s room, as is recommended. The workers were aware of the monitoring and were well aware of the recommended guidelines for hand cleansing.

The data proved both of the research team’s primary predictions true. The research showed that, over the course of a single, typical 12-hour work shift, hand hygiene compliance rates dropped by 8.7 percentage points on average from the beginning of the shift to the end. It also showed that taking a break between consecutive work shifts can help workers reset their compliance rates, especially if the break follows a more intense week of work.

“When people end their shift, the more worn out they are, the more they need a break and the bigger the benefits of the break are,” Milkman notes. “If they had a really busy week, essentially the main effects are magnified.”

The effect isn’t driven by the time of day or the particular shift a caregiver works, or the caregiver him or herself, she adds. It is affected by how difficult the shift is. The more intense the shift, the faster the compliance rates drop off. Also, “the longer a break is, the better it is,” she says.

If hand hygiene compliance rates increased by 8.7 percentage points across the board during a typical work shift, this could potentially eliminate as many as 1.2 million infections per year.

A ‘Mission Critical’ Task

An 8.7-percentage point drop in hygienic compliance over the course of a shift has potentially huge implications for patient safety in the country, Milkman notes. A study of Swiss hospitals found that a one percentage point increase in hand cleaning rates reduced the number of infections per 1,000 admitted patients by 3.9 instances. Another study estimated that the per-patient cost of a health care related infection is $20,549. Applying that data to their work, Dai, Milkman, Hofmann and Staats estimate that if hand hygiene compliance rates increased by 8.7 percentage points across the board during a typical work shift, this could potentially eliminate as many as 1.2 million infections per year, save up to $25 billion and prevent up to 70,000 unnecessary deaths in the United States.

“This 8.7 percentage point drop is quite a big deal…. Those numbers are really shocking in this context,” Milkman says. “Sanitizing hands is a mission critical task. Even though it’s secondary, it has huge implications for the number of lives lost.”

Even small improvements in this decline could be beneficial, the researchers write, given the volume of patient-caregiver interactions each year in the United States and across the world. Although the study was focused on health care given the availability of the data, the same implications could, in theory, be found in nearly any field.

“The decline in compliance may apply to other secondary tasks that require self-regulation, particularly in situations where there is a constant ‘switching of gears’ between primary and second tasks,” Dai notes.

“It’s a much bigger deal that just health care,” Milkman adds. “This is where we’re studying the problem, but the problem could need attending to anywhere.”

“The decline in compliance may apply to other secondary tasks that require self-regulation, particularly in situations where there is a constant ‘switching of gears’ between primary and second tasks.” –Hengchen Dai

Further research can focus on ways to mitigate the decline, including the effects of breaks during the work day. The same research team is also planning to use the Proventix data to examine how the use of electronic monitoring technology impacts workers’ compliance. Is worker compliance with professional standards improved when workers feel observed, and do habits remain or revert back if and when monitoring technologies are removed?

In the immediate future, however, Milkman and Dai hope that the research will prod leaders in the health care industry to find ways to help their workers follow through on their tasks — both big and small.

“I hope that a lesson is learned and that things improve,” Milkman says. “Being a caregiver is demanding, and it’s difficult to overstate how hard that job is…. When focusing on their primary tasks, caregivers may not realize how many lives they could save by changing compliance with these important but secondary safety behaviors.”

Dai adds that managers “should be aware that employees may attend to vital secondary tasks less as their work shifts wear on. In light of this, reminding employees of vital secondary tasks may be particularly effective, or need to be made particularly salient, as a work shift approaches its conclusion.”