The use of human factors methods to identify and mitigate safety issues in radiation therapy.
OBJECTIVE
New radiation therapy technologies can enhance the quality of treatment and reduce error. However, the treatment process has become more complex, and radiation dose is not always delivered as intended. Using human factors methods, a radiotherapy treatment delivery process was evaluated, and a redesign was undertaken to determine the effect on system safety.


METHODS
An ethnographic field study and workflow analysis was conducted to identify human factors issues of the treatment delivery process. To address specific issues, components of the user interface were redesigned through a user-centered approach. Sixteen radiation therapy students were then used to experimentally evaluate the redesigned system through a usability test to determine the effectiveness in mitigating use errors.


RESULTS
According to findings from the usability test, the redesigned system successfully reduced the error rates of two common errors (p<.04 and p<.01). It also improved the mean task completion time by 5.5% (p<.02) and achieved a higher level of user satisfaction.


CONCLUSIONS
These findings demonstrated the importance and benefits of applying human factors methods in the design of radiation therapy systems. Many other opportunities still exist to improve patient safety in this area using human factors methods.
Healthcare Human Factors, University Health Network, Ontario, Canada. alvita.chan@uhn.on.ca
Alvita J
AJ
Chan
Mohammad K
MK
Islam
Tara
T
Rosewall
David A
DA
Jaffray
Anthony C
AC
Easty
Joseph A
JA
Cafazzo
D057189:Checklist; D006804:Ergonomics; D006801:Humans; D019300:Medical Errors / Q000517:prevention & control*; D010315:Particle Accelerators; D011878:Radiotherapy / Q000009:adverse effects*; D012449:Safety