Surgeons Outperform Normative Controls, but Age-Related

Decay of Skills Persists

Z Boom-Saad*, SA Langenecker†, LA Bieliauskas†, C Graver†, J O’Neill†, A Caveney†, PG Gauger*‡,

LJ Greenfield*, and RM Minter*‡

Departments of Surgery*, Neuropsychology†, and Medical Education‡

Background

• Variation exists with respect to psychomotor and procedural learning capabilities

• Preliminary work by our group demonstrated that practicing surgeons outperformed normative controls on a series of neuropsychological tests – Cambridge Neuropsychological Test Automated Battery (CANTAB)

Research Question

Do surgeons outperform normative controls due to experience gained during surgical training, or is this

difference present at baseline in those individuals drawn to a surgical career?

Methods

• 308 practicing surgeons age 45-75 years performed a battery of CANTAB tests at the American College of Surgeons Meeting (2001-2004)

• 21 medical students ( age 24-35 years) entering General or Plastic Surgery or Urology residency performed the same tests (2005-2006)

• For analysis, subjects were divided into three age groups– 20-35 yrs (medical students, n=21, 28% ♀)– 45-60 yrs (practicing surgeons, n=139, 18% ♀)– 61-75 yrs (practicing surgeons, n=169, 1.8% ♀)

Methods

• Performance was compared between surgeon groups as well as to age-matched normative comparison groups

• IQ of 120 was selected for normative comparison for all groups

• ANOVA was used for comparing group performance and post-hoc analysis was performed using least squares difference

• Significance was set at p<0.05• Study was approved by the University of

Michigan Institutional Review Board

CANTAB

• CANTAB battery of tests– Reaction time and efficiency of motion (RTI)– Rapid visual information processing (RVIP)– Visual memory and rapid learning index (PAL)

• Uses a touchscreen so effect of prior computer experience is minimized

• CANTAB provides age-matched normative control subject data against which performance can be compared

Reaction Time Task (RTI)

• Subject must release pad in response to a visual stimulus

• Release time and time to target is measured

• Measures efficiency of motion and response time

Rapid Visual Information Processing (RVIP)

• Test of sustained attention with a small working memory component

• Measures stimulus response time and accuracy (% correct hits)

Paired Associates Learning (PAL)

• Test of attention and visual memory – an index of rapid learning

• Measures how a subject processes visually complex information

• Performance recorded as overall accuracy on task

Results – Reaction Time Task

Subject age range

Res

pon

se ti

me

(sec

onds

)0

50

100

150

200

250

300

350

400

450

20-35 years 45-60 years 61-75 years

*p<0.05

Subject age range

Mov

emen

t tim

e (s

econ

ds)

0

100

200

300

400

500

600

20-35 years 45-60 years 61-75 years

*p<0.05

RTI – Total Movement Time RTI – Total Reaction Time

Results – Rapid Visual Information Processing

Subject age range

Acc

urac

y ra

te -

% c

orre

ct h

its0

20

40

60

80

100

20-35 years 45-60 years 61-75 years

*p<0.05

Subject age range

Res

pon

se ti

me

(sec

onds

)

0

100

200

300

400

500

600

20-35 years 45-60 years 61-75 years

*p<0.05

RVIP – Percent Correct HitsRVIP – Stimulus response time

Results – Paired Associates Learning (Visual Memory)

Subject age range

Sta

ges

com

plet

ed

first

tria

l (#)

0

1

2

3

4

5

20-35 years 45-60 years 61-75 years

*p<0.05

PAL – Stages completed on first trial PAL – Total adjusted errors

Subject age range

To

tal a

dju

sted

err

ors

(#)

0

10

20

30

40

20-35 years 45-60 years 61-75 years

*p<0.05

Surgeon Group versus NormsRTI – Total Movement Time

Subject age range

Mov

emen

t tim

e (s

econ

ds)

0

100

200

300

400

500

600

700

800Surgeon groupNormative controls

20-35 years 45-60 years 61-75 years

* **

Surgeon Group versus NormsRTI – Total Reaction Time

Subject age range

Res

pon

se ti

me

(se

cond

s)

0

100

200

300

400

500Surgeon groupNormative controls

20-35 years 45-60 years 61-75 years

* *

Surgeon Group versus NormsRVIP – Accuracy Rate

Subject age range

Acc

urac

y ra

te -

% c

orre

ct h

its

0102030405060708090

100Surgeon groupNormative controls

20-35 years 45-60 years 61-75 years

**

Summary

• Decline in visual memory and psychomotor performance occurs with advancing age

• Improved performance on the selected CANTAB tests by the surgeon groups appears to be a factor which is present at baseline and is not a result of surgical training

Limitations of Study

• These tests do not account for the effect of experience on procedural learning ability

• Subjects did not undergo IQ testing so exact normative control comparisons could not be made

• Medical student group was limited in size and to one institution – expansion of this group would strengthen the study

Conclusions

• Older surgeons may require additional trials for mastery of visually complex surgical procedures as compared to younger surgeons

• CANTAB may be a useful construct for evaluating residents who appear to have difficulty with visual memory psychomotor performance

Acknowledgements

• Dr. Lazar Greenfield• Drs. Scott Langenecker and Linas Bieliauskas

• Association for Surgical Education Foundation’s Center for Excellence in Surgical Education, Research, and Training (CESERT) Grant