Some radiologists fall asleep at the wheel

November 27, 2005

Better eyesight may not guarantee a better read, according to research presented Sunday at the RSNA meeting. Fatigue plays a large part in interpretation accuracy, and nearly 50% of participants in a multicenter survey admitted to falling asleep while reading a study on call.

Better eyesight may not guarantee a better read, according to research presented Sunday at the RSNA meeting. Fatigue plays a large part in interpretation accuracy, and nearly 50% of participants in a multicenter survey admitted to falling asleep while reading a study on call.

Additionally, respondents attributed more than 17% of missed findings to lack of sleep, according to Dr. Nabile Safdar, assistant professor of diagnostic radiology at the University of Maryland Medical Center in Baltimore.

Researchers found that radiologists participating in the visual acuity study had not undergone an eye exam in more than two years.

Safdar and colleagues originally set out to measure the visual acuity of radiologists in a soft-copy environment, and to determine whether that acuity decreased over the course of a work day.

Researchers measured visual acuity in 23 radiologists at three large tertiary hospitals. Participating radiologists used both 5-megapixel CRT and 2-megapixel LCD displays. Investigators administered vision tests between 7:50 a.m. and 10:30 am, 12:00 p.m. and 3:30 pm, and after 3:30 pm.

The radiologists also answered questions about their age, ophthalmic surgical history, or medical history, as well how many hours of sleep they received the previous night.

Safdar reported that the average visual acuity of all the radiologists was 20/16, better than a normal 20/20 score. He also found no significant difference in visual acuity as measured during different times of day.

"We were, however, surprised that over one-fifth of the radiologists had less than 20/20 vision," Safdar said.

Some radiologists even had 20/30 vision, which would be the equivalent of sitting about 50% farther away from their workstations then they normally do while trying to interpret an exam, he said.

On average, radiologists had not had an eye exam in more than two years, according to study results.

"It is important for departments to encourage radiologists to maintain their visual health," Safdar said.

While most of the radiologists reported nearly seven hours of sleep the night before, those younger than 35 received only an hour or less of sleep. Safdar attributed this to the fact that this population of radiologists is most likely to be on call. This prompted researchers to conduct a second survey gauging fatigue in the younger population.

Twenty one respondents replied to the survey. The average age of the participants was 29. Nearly 30% of the respondents reported that they had fallen asleep while driving when they were on call. More than 47% of the respondents admitted to "micro-sleeps" while reading a study on call. Safdar defined a "micro-sleep" as a brief period of sleep that the person isn't even aware that they have taken.

The researchers are beginning preliminary studies to further study the effects of fatigue on a radiologist's interpretation accuracy, he said.