Idle time: an underdeveloped performance metric for assessing surgical skill.
BACKGROUND
The aim of this study was to evaluate validity evidence using idle time as a performance measure in open surgical skills assessment.


METHODS
This pilot study tested psychomotor planning skills of surgical attendings (n = 6), residents (n = 4) and medical students (n = 5) during suturing tasks of varying difficulty. Performance data were collected with a motion tracking system. Participants' hand movements were analyzed for idle time, total operative time, and path length. We hypothesized that there will be shorter idle times for more experienced individuals and on the easier tasks.


RESULTS
A total of 365 idle periods were identified across all participants. Attendings had fewer idle periods during 3 specific procedure steps (P < .001). All participants had longer idle time on friable tissue (P < .005).


CONCLUSIONS
Using an experimental model, idle time was found to correlate with experience and motor planning when operating on increasingly difficult tissue types. Further work exploring idle time as a valid psychomotor measure is warranted.
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA. Electronic address: amaag@uwhealth.org.
Anne-Lise D
AL
D'Angelo
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA; Department of Kinesiology, School of Education, University of Wisconsin - Madison, 2000 Observatory Drive, Madison, WI 53706, USA.
Drew N
DN
Rutherford
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA.
Rebecca D
RD
Ray
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA; Department of Electrical and Computer Engineering, College of Engineering, University of Wisconsin - Madison, 1415 Engineering Drive, Madison, WI 53706, USA.
Shlomi
S
Laufer
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA.
Calvin
C
Kwan
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA.
Elaine R
ER
Cohen
Department of Kinesiology, School of Education, University of Wisconsin - Madison, 2000 Observatory Drive, Madison, WI 53706, USA.
Andrea
A
Mason
Department of Surgery, School of Medicine and Public Health, University of Wisconsin - Madison, 750 Highland Avenue, Madison, WI 53726, USA.
Carla M
CM
Pugh
D002983:Clinical Competence / Q000706:statistics & numerical data*; D006801:Humans; D008953:Models, Anatomic; D010865:Pilot Projects; D013536:Suture Techniques / Q000592:standards*; D013997:Time Factors
Assessment; Idle time; Motion tracking; Path length; Simulation; Surgical skills