Surgeon Specialty and Operative Mortality With Lung Resection PP Goodney, FL Lucas, TS Stukel, JD...

Surgeon Specialty and Operative Mortality With

Lung Resection

PP Goodney, FL Lucas, TS Stukel, JD Birkmeyer

VA Outcomes Group, White River Junction, VT

Dartmouth-Hitchcock Medical Center, Lebanon, NH

Background

• Several studies have reported variation in outcomes according to surgeon specialty– colorectal resection for cancer

• Wigmore et al, Ann Surg 1999

– carotid endarterectomy• Hannan et al, Stroke 2001

• Not all studies have confirmed this finding• Cowan et al, JACS 2002

Lung resection

• Resection for lung cancer– approximately 25,000 cases per year in the

U.S.– Performed by:

• General surgeons• Cardiothoracic surgeons• Non-cardiac thoracic surgeons

www.seer.cancer.gov

Research question

Does surgeon specialty affect operative mortality in lung resection for lung

cancer?

Subjects and databases• Study population

– All Medicare beneficiaries 1998-1999– Age 65-99

• Patient selection– Procedure code for lung resection

• (pneumonectomy or lobectomy)

– Diagnosis code for lung cancer– Unique physician identifier number (UPIN)

present on discharge abstract

Unique physicians in lung resection

inpatient filen=4793

Surgeon

Specialty Assignment



Yesn=2179

Surgeon


American Board of Thoracic Surgery

member?

Non=2614



Yesn=2179

Cardiothoracic surgeonn=1516

Non-cardiac thoracic surgeon

n=663

Surgeon



member?

Perform CABG?

Yes No

Non=2614



Yesn=2179

Cardiothoracic surgeonn=1516

Non-cardiac thoracic surgeon

n=663

General surgeonn=2614

Surgeon



member?

Perform CABG?

Yes No

Non=2614

Analysis

• Unit of analysis: patient

• Main exposure: surgeon specialty– General, cardiothoracic, non-cardiac

thoracic

• Main outcome measure: operative mortality– Combination of death before discharge or

within thirty days of the index procedure

Analysis

• Using multiple logistic regression models, adjusted for the following:

Patient variables:

Age, sex, race

Comorbidity score

Admission acuity

Extent of resection

Surgeon variables:

Surgeon volume

Clustering

Hospital variables:

Hospital volume

Bed size

Teaching status

Medical school affiliation

ACS-approved cancer center

RESULTS

Patient characteristics

General surgeons

Cardiothoracic surgeons

Non-cardiac thoracic

surgeons

No. patients (n) 9,263 9,792 6,490

Age >75 (%) 69.1 69.9 70.4

Female (%) 42.5 42.3 44.8

African American (%) 4.7 4.2 6.0

Charlson score >3 (%) 44.5 46.2 48.4

Pneumonectomy (%) 9.6 11.5 11.5

Hospital characteristics

General surgeons



surgeons

Bed size 309 433 357

Teaching status (% with residents)

31.0 56.7 58.1

Medical school affiliation (%) 22.4 64.7 57.6

ACS cancer program (%) 53.4 80.7 73.8

>45 lung resections per year (%) 8.4 16.7 13.4

Surgeon characteristics

General surgeons



surgeons

No. surgeons (n) 2,614 1,516 663

Surgeon age (years) 51.8 51.8 57.9

Years in practice (years) 21.6 21.9 30.5

Average cases/yr, lung resection 3.1 6.5 10.2

>20 lung resections per year (n, %) 71 (2.7%) 65 (4.3%) 87 (13%)

Adjusted operative mortality, by surgeon subspecialty

7.26.4

5.3

0.0

2.0

4.0

6.0

8.0

Surgeon specialty

Gen

eral

Car

diot

hora

cic

Non

-car

diac

th

orac

icp <0.001 between all groups

Adjusted operative mortality, by extent of resection

6.2

16.4

5.4

14.5

4.5

11.9

0.0

5.0

10.0

15.0

20.0

Lobectomy Pneumonectomy

Gen

eral

Car

dio.

NC

TS

Gen

eral

Car

diot

hora

cic

NC

TS

p <0.001 between all groups

Adjusted operative mortality, with high-volume surgeons

6.2 6.1

4.7

0.0

2.0

4.0

6.0

8.0

Surgeon specialty

Gen

eral

Car

diot

hora

cic

Non

-car

diac

th

orac

icp <0.01 between non-cardiac thoracic surgeons and others

Adjusted operative mortality, in high-volume hospitals

5.8 5.9

4.3

0.0

2.0

4.0

6.0

8.0

Surgeon specialty

Gen

eral

Car

diot

hora

cic

Non

-car

diac

th

orac

icp <0.01 between non-cardiac thoracic surgeons and others

Odds ratios of operative mortality

General surgeons

Cardio-thoracic

surgeons


surgeons

Crude 1.00 0.84 0.68

Adjusted for patient characteristics 1.00 0.84 0.68

Patient and hospital characteristics 1.00 0.84 0.68

Patient and hospital characteristics, and hospital volume 1.00 0.87 0.74

Patient and hospital characteristics, hospital and surgeon volume 1.00 0.88 0.76

Summary

• Operative mortality with lung resection varies by surgeon specialty

• Risks were lowest for non-cardiac thoracic surgeons

• Hospital and surgeon volume account for some, but not all of this effect

Limitations

• Administrative data for risk adjustment

• Error in assignment of surgeon specialty– Bias would tend towards the null

Why does performance differ across specialty?

• Additional training• Structural differences across specialty

– Larger hospitals– Medical school affiliations– ACS-approved cancer programs

• Another possibility –– Differences in processes of care

• Intensivist-managed ICUs, epidural catheters, pulmonary protocols

• Many of these processes are unmeasured in current quality improvement initiatives such as the STS database

Do our findings matter?

• Although these differences are statistically significant, are they clinically important?

• Differences are small (~1%) for lobectomy, but larger (~5%) for pneumonectomy

• How much is enough?– Only patients can decide

Conclusion

• Surgeon specialty impacts operative mortality with lung resection

• Some, but not all of this difference can be explained by volume

• Further study of these differences may hold potential for improvement

Acknowledgement

• Scottie Siewers

• VA Outcomes Group

Surgeon Specialty and Operative Mortality With Lung Resection PP Goodney, FL Lucas, TS Stukel, JD...

Documents

Transcript of Surgeon Specialty and Operative Mortality With Lung Resection PP Goodney, FL Lucas, TS Stukel, JD...