Perioperative Outcomes Among Surgeons Who Operated the Night Prior 10.8.21

Perioperative Outcomes Among Surgeons Who Operated the Night

Prior

Eric Sun, MD/PhD

Michelle M. Mello, JD/PhD

Michelle T. Vaughn, MPH

Sachin Kheterpal, MD/MBA

Mary T. Hawn, MD

Justin B. Dimick, MD/MPH

Anupam B. Jena, MD/PhD

Disclosures

• Research support from NIDA, NIA, and AHRQ

• Advisory Board of Lucid Lane, LLC

• Consulting fees from Analysis Group, Inc.

Motivation

• Fatigue has been shown to adversely affect performance across a variety of domains

(Neu et al., 2011; Goode 2003; Fullagar 2015)

• Concerns about fatigue and patient outcomes (Barger 2006; Gates 2018)

• While residents face duty hour restrictions, attendings do not

• Is this safe for patients?

Summary of Findings

• Operating overnight was not associated with an increased risk of in-hospital death

or major complication among the subsequent day’s cases

• Small decrease (?) among subsequent day’s cases

• Results generally robust across a variety of subgroup and sensitivity analyses

Outline

• Background

• Sample

• Statistical Approach

• Results

• Conclusion

Outline

• Background

• Sample

• Statistical Approach

• Results

• Conclusion

Background

• Previous work

• Gates (2018): Systematic review of 47 studies, generally found no association

between fatigue and poorer outcomes

• Govindarajan (2015): Retrospective analysis of ~40k patients undergoing surgery at

a Canadian province: no association between operating overnight and outcomes on

the next day’s cases

• Limitations of previous work

• Underpowered to study mortality/complications

• Subject to confounding (surgeons who work overnight are different from those who

don’t)

• Self-reported overnight operating

• Overly stringent definitions f operating overnight

Outline

• Background

• Sample

• Statistical Approach

• Results

• Conclusion

Sample

• Inclusion criteria

• Cases between January 1, 2010 and August 30, 2020

• Nonmissing data on comorbidities, mortality, surgery CPT code, and whether the

surgeon operated the previous night

• Nonmissing data on case times

• “Major therapeutic procedure” as defined by AHRQ

Sample

• Initial Sample 2,110,956 cases

• Exclusion criteria

• Surgeons who never operated overnight (n=1,332,069)

• >1 attending surgeon (n=54,838)

• Missing data: age (n=89), ASAPS (n=7,902)

• ASA 5/6 (n=1,351)

• Low risk/out of OR procedures

• Upper endoscopy (n=47,127)

• Lower endoscopy (n=22,262)

• Opthalmologic surgeries (n=41,851)

• CVC access (n=16,435)

• Surgery CPTs with <100 observations (n=58,753)

• Surgeons with <100 observations (n=30,295)

Sample

• Final Sample

• 498,234 cases

• 1,131 surgeons

• 20 US institutions

Outline

• Background

• Sample

• Statistical Approach

• Results

• Conclusion

Statistical Approach

• Primary Outcome: In-Hospital Death or Major Complication

• Major Complications: Thromboembolic events, MI, stroke, PNA, sepsis

• Identified by discharge diagnosis codes

• Secondary Outcomes

• Surgery length (surgery end-surgery start)

• Death

• Major complications

• Minor complications (UTI, SSI)

Statistical Approach

• Exposure

• Having operated overnight before the current day’ surgery

• “Overnight” defined as 2300-0700

• Measured using surgery start and end times

• Baseline model was yes/no for any overnight operating time

• Sensitivity analyses examined alternate definitions

Statistical Approach

• Multivariable Linear Regression

• Key innovation is use of ”surgeon fixed effects”

• Reduces confounding because we are not comparing surgeons who operate

overnight to those who do not

• Compare a given surgeon’s cases where the surgeon operated overnight

compared to the cases where the same surgeon did not

• Additional variables include

• Patient characteristics (Age, sex, comorbidities)

• Surgery CPT Fixed Effects

• Hour of Surgery

Statistical Analyses

• Subgroup Analysis

• “High risk” patientsupper 25

percentile of predicted mortality/major

complication

• Sensitivity Analysis

• Two alternate approaches to measuring intensity of operating overnight

• Five groups:

• no overnight operating

• 0-2h

• 2-4h

• 4-6h

• 6-8h

• Introduce hours operated overnight as a linear variable

Outline

• Background

• Sample

• Statistical Approach

• Results

• Conclusion

Surgeon Operated the Previous Night

(N=13,098)

Surgeon did Not Operate the Previous Night

(N=485,136)

p-value/g-value

Patient demographics

Age, mean (s.e)

53.91 (0.15) 55.32 (0.02) <0.001/0.09

Male, % (s.e.)

52.32 (0.44) 46.72 (0.07) <0.001/0.11

Comorbidities, % (s.e.)

Congestive Heart Failure

8.73 (0.25) 5.32 (0.03) <0.001/0.15

Arrhythmia

18.46 (0.34) 13.07 (0.05) <0.001/0.16

Valvular Disease

7.72 (0.23) 5.18 (0.03) <0.001/0.11

Pulmonary Circulatory Disorders

4.57 (0.18) 2.94 (0.02) <0.001/0.10

Peripheral Vascular Disease

9.04 (0.25) 5.36 (0.03) <0.001/0.16

Hypertension, Uncomplicated

32.75 (0.41) 29.38 (0.07) <0.001/0.07

Hypertension, Complicated

11.70 (0.28) 7.16 (0.04) <0.001/0.17

Paralysis

1.70 (0.11) 1.08 (0.01) <0.001/0.06

Neurological Disorder

6.66 (0.22) 4.55 (0.03) <0.001/0.10

Chronic Pulmonary Disease

14.05 (0.30) 11.61 (0.05) <0.001/0.08

Diabetes, Uncomplicated

11.66 (0.28) 9.95 (0.04) <0.001/0.06

Diabetes, Complicated

5.10 (0.19) 3.09 (0.02) <0.001/0.12

Hypothyroidism

7.66 (0.23) 8.29 (0.04) 0.010/0.02

Chronic Renal Failure

12.35 (0.29) 7.73 (0.04) <0.001/0.17

Liver Disease

5.47 (0.20) 4.00 (0.03) <0.001/0.07

Peptic Ulcer Disease

0.73 (0.07) 0.58 (0.01) 0.030/0.02

AIDS

0.41 (0.06) 0.24 (0.01) <0.001/0.03

Lymphoma

1.00 (0.09) 1.38 (0.02) <0.001/0.03

Metastatic Disease

6.06 (0.21) 13.99 (0.05) <0.001/0.23

Solid Tumor

13.83 (0.30) 24.65 (0.06) <0.001/0.25

Rheumatoid Arthritis

2.79 (0.14) 2.32 (0.02) <0.001/0.03

Coagulopathy

7.59 (0.23) 4.23 (0.03) <0.001/0.17

Obesity

16.44 (0.32) 14.96 (0.05) <0.001/0.04

Weight Loss

5.79 (0.20) 3.81 (0.03) <0.001/0.10

Fluid or Electrolyte Disorder

17.58 (0.33) 9.94 (0.04) <0.001/0.25

Blood Loss

1.21 (0.10) 0.85 (0.01) <0.001/0.04

Iron Deficiency Anemia

2.72 (0.14) 2.07 (0.02) <0.001/0.05

Alcohol Abuse

1.12 (0.09) 0.66 (0.01) <0.001/0.06

Drug Abuse

4.21 (0.18) 2.42 (0.02) <0.001/0.11

Psychosis

0.75 (0.08) 0.51 (0.01) <0.001/0.03

Depression

11.35 (0.28) 9.95 (0.04) <0.001/0.05

ASA Score

Physical Status Score, mean (s.e.)

2.62 (0.01) 2.53 (0.00) <0.001/0.13

Emergent Case, % (s.e.)

8.70 (0.25) 2.60 (0.02) <0.001/0.37

High-Risk Patients, % (s.e.) 35.9 (0.4) 24.7 (0.1)

<0.001/0.26

4.8

5.2

5.4

5.6

5.8

6.2

6.4

6.6

Overnight Work No Overnight Work

Incidence (%)

Summary of Outcomes

Operating

Overnight

No Operating

Overnight

Primary Outcome 5.89 5.87 0.93

Surgery Length

(min)

112.7 117.4 0.020

Death (%) 0.87 0.89 0.82

Major Cx (%) 5.40 5.34 0.83

Minor Cx (%) 2.34 2.27 0.67

Hours operated night prior modeled as a categorical variable

Amount of time worked between 11pm and 7am

the previous night

Death or major

complication, adjusted %

(95% CI)

Absolute adjusted

difference (95% CI)

None (N=485,136) 5.87 (5.85 to 5.88) -

>0 to <2 hours (N=9,117) 6.05 (5.50 to 6.60)

0.18%

(-0.38% to 0.75%)

p=0.52

2 to <4 hours (N=2,116) 5.47 (4.35 to 6.59)

-0.40%

(-1.52% to 0.72%)

p=0.49

4 to <6 hours (N=883) 6.01 (4.17 to 7.85)

0.15%

(-1.70% to 1.99%)

p=0.88

6-8 hours (N=982) 5.21 (3.60 to 6.83)

-0.65%

(-2.27% to 0.97%)

p=0.43

Hours worked night prior modeled linearly

Absolute adjusted change in death or major

complication per additional hour worked (95%

CI)

-0.05% (-0.22% to 0.12%)

p=0.57

Conclusions

• Surgeons who operated overnight—even for extensive periods of time—did not have

worse outcomes when the operated the next day

• Results were robust to a variety of subgroup and sensitivity analyses

• Allowing surgeons who operated overnight to work the next day appears to be safe—

at least as it is practiced in this sample of (large) institutions