Supplement for: Benchmarking the Value of Care: Variability in Hospital Costs for Common Operations and Its Association with Procedure Volume Cheryl K. Zogg MSPH, MHS,

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Supplement for:

Benchmarking the Value of Care: Variability in Hospital Costs for Common Operations and Its Association with Procedure Volume

Cheryl K. Zogg MSPH, MHS,

^1,2

Andrew C. Bernard MD,

³

Sameer A. Hirji MD, MPH,

²

Joseph P.

Minei MD, MBA,

⁴

Kristan L. Staudenmayer MD,

⁵

Kimberly A. Davis MD, MBA

¹

1. Yale School of Medicine, New Haven, CT

2. Center for Surgery and Public Health, Department of Surgery, Brigham & Women’s Hospital, Harvard Medical School, and Harvard TH Chan School of Public Health, Boston, MA

3. Department of Surgery, University of Kentucky College of Medicine, Lexington, KY 4. Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 5. Department of Surgery, Stanford School of Medicine, Stanford, CA

Key words: Cost; Volume; Benchmarking; Appendectomy; Cholecystectomy; Acute Care

Surgery; Emergency General Surgery

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1. Total hospital charges in 2016 (2019 USD)

Laparoscopic appendectomy Laparoscopic cholecystectomy

Minimum 25th percentile Median Mean 75th percentile Maximum Minimum 25th percentile Median Mean 75th percentile Maximum $ 6,982 $ 29.180 $ 38,695 $ 43,639 $ 53,841 $ 148,822 $ 8,144 $ 33,352 $ 44,585 $ 51,019 $ 62,820 $ 177,422

SFigure 1A. Plot of median total hospital charges in 2019 USD (IQR) for laparoscopic appendectomy and cholecystectomy, NIS 2016

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2. Expected (risk-adjusted) total hospital costs in 2016 (hospitalwide CCR-derived costs; 2019 USD)

Minimum 25th percentile Median Mean 75th percentile Maximum Minimum 25th percentile Median Mean 75th percentile Maximum $ 7,312 $ 9,190 $ 9,924 $ 10,016 $ 10,813 $ 23,163 $ 8,553 $ 10,844 $ 11,649 $ 11,932 $ 12,864 $ 23,395

SFigure 1B. Plot of median risk-adjusted costs in 2019 USD (IQR) for laparoscopic appendectomy and cholecystectomy, NIS 2016

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3. Expected (risk-adjusted) total hospital costs in 2016, including socio-economic variables for insurance, income, and race/ethnicity (hospitalwide CCR-derived costs; 2019 USD)

Minimum 25th percentile Median Mean 75th percentile Maximum Minimum 25th percentile Median Mean 75th percentile Maximum $ 7,022 $ 8,715 $ 9,472 $ 9,538 $ 10,292 $ 21,967 $ 8,025 $ 10,305 $ 11,114 $ 11,369 $ 12,253 $ 22,117

SFigure 1C. Plot of median risk-adjusted costs in 2019 USD (IQR) for laparoscopic appendectomy and cholecystectomy, NIS 2016

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SFigure 2A. Spearman’s rank correlation between annual procedure volume and median total hospital costs in 2019 USD, NIS 2014

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SFigure 2B. Spearman’s rank correlation between annual procedure volume and median total hospital costs in 2019 USD, NIS 2016

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STable 1. Laparoscopic appendectomy and laparoscopic cholecystectomy regression results:

Association of annual procedure volume with median total hospital costs in 2019 USD

Laparoscopic appendectomy 2014 (ICD9 procedure code 47.01): Difference in median total hospital cost (2019 USD)

Unadjusted 95%CI p-value Risk-adjusted* 95%CI p-value

I. Categorical model

Quintile 1 - lowest volume (reference) -- -- -- -- -- -- -- --

Quintile 2 -2610 -3122 -2097 <0.001 -2049 -2543 -1554 <0.001

Quintile 3 -4299 -4805 -3793 <0.001 -2979 -3504 -2454 <0.001

Quintile 4 -4884 -5391 -4377 <0.001 -3114 -3676 -2553 <0.001

Quintile 5 - highest volume -5666 -6176 -5156 <0.001 -3307 -3922 -2591 <0.001

Per 10 additional operations each year…

II. Ln-transformed model

Exponentiated mean difference -434 -481 -387 <0.001 -152 -205 -98 <0.001

III. Quantile regression

Median (50th percentile) -270 -308 -233 <0.001 -108 -153 -64 <0.001

60th percentile -311 -355 -267 <0.001 -114 -165 -63 <0.001

70th percentile -371 -431 -311 <0.001 -130 -197 -63 <0.001

80th percentile -443 -515 -372 <0.001 -154 -238 -70 <0.001

90th percentile -568 -717 -419 <0.001 -165 -299 -32 <0.001

Laparoscopic appendectomy 2016 (ICD10 procedure code 0DTJ4ZZ): Difference in median total hospital cost (2019 USD)

Quintile 2 -2452 -3401 -1863 <0.001 -1663 -2225 -1102 <0.001

Quintile 3 -4330 -4918 -3740 <0.001 -2846 -3443 -2249 <0.001

Quintile 4 -5163 -5752 -4573 <0.001 -3078 -3716 -2439 <0.001

60th percentile -284 -338 -229 <0.001 -131 -197 -65 <0.001

70th percentile -344 -406 -283 <0.001 -133 -211 -55 <0.001

80th percentile -415 -518 -311 <0.001 -183 -277 -89 <0.001

90th percentile -554 -713 -396 <0.001 -174 -313 -37 0.013

*Risk-adjusted for hospital bedsize, hospital teaching status, hospital rurality, hospital geographic region, patient age, patient gender, patient APR-DRG risk of mortality, patient APR-DRG severity, and calculated patient Elixhauser Comorbidity Index All models were based on nationally-weighted mixed-effects regression and robust standard errors

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Laparoscopic cholecystectomy 2014 (ICD9 procedure code 51.23): Difference in median total hospital cost (2019 USD)

Quintile 2 -4023 -4565 -3481 <0.001 -3947 -4489 -3406 <0.001

Quintile 3 -5260 -5812 -4708 <0.001 -4862 -5462 -4621 <0.001

Quintile 4 -5971 -6519 -5422 <0.001 -5290 -5945 -4634 <0.001

60th percentile -165 -187 -142 <0.001 -77 -107 -46 <0.001

70th percentile -201 -226 -176 <0.001 -88 -123 -53 <0.001

80th percentile -242 -280 -205 <0.001 -104 -153 -56 <0.001

90th percentile -312 -378 -247 <0.001 -137 -214 -59 <0.001

Laparoscopic cholecystectomy 2016 (ICD10 procedure code 0FT44ZZ): Difference in median total hospital cost (2019 USD)

Quintile 2 -3772 -4328 -3215 <0.001 -3604 -4162 -3046 <0.001

Quintile 3 -4308 -4859 -3757 <0.001 -3834 -4451 -3217 <0.001

Quintile 4 -5175 -5725 -4624 <0.001 -4474 -5152 -3795 <0.001

60th percentile -165 -187 -142 <0.001 -75 -108 -42 <0.001

70th percentile -201 -226 -176 <0.001 -91 -132 -48 <0.001

80th percentile -242 -280 -205 <0.001 -125 -174 -76 <0.001

90th percentile -312 -378 -247 <0.001 -165 -252 -78 <0.001

*Risk-adjusted for hospital bedsize, hospital teaching status, hospital rurality, hospital geographic region, patient age, patient gender, patient APR-DRG risk of mortality, patient APR-DRG severity, and calculated patient Elixhauser Comorbidity Index All models were based on nationally-weighted mixed-effects regression and robust standard errors

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