World Journal of Surgery

, Volume 42, Issue 8, pp 2344–2347 | Cite as

How Much Data are Good Enough? Using Simulation to Determine the Reliability of Estimating POMR for Resource-Constrained Settings

  • Isobel H. Marks
  • Zhi Ven Fong
  • Sahael M. Stapleton
  • Ya-Ching Hung
  • Yanik J. Bababekov
  • David C. ChangEmail author
Original Scientific Report



Perioperative mortality rate (POMR) is a suggested indicator for surgical quality worldwide. Currently, POMR is often sampled by convenience; a data-driven approach for calculating sample size has not previously been attempted. We proposed a novel application of a bootstrapping sampling technique to estimate how much data are needed to be collected to reasonably estimate POMR in low-resource countries where 100% data capture is not possible.

Material and methods

Six common procedures in low- and middle-income countries were analysed by using population database in New York and California. Relative margin of error by dividing the absolute margin of error by the true population rate was calculated. Target margin of error was ±50%, because this level of precision would allow us to detect a moderate-to-large effect size.

Results and discussion

Target margin of error was achieved at 0.3% sampling size for abdominal surgery, 7% for fracture, 10% for craniotomy, 16% for pneumonectomy, 26% for hysterectomy and 60% for C-section. POMR may be estimated with fairly good reliability with small data sampling. This method demonstrates that it is possible to use a data-driven approach to determine the necessary sampling size to accurately collect POMR worldwide.


Compliance with ethical standards

Conflict of interest

The authors have indicated they have no disclosures.


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Copyright information

© Société Internationale de Chirurgie 2018

Authors and Affiliations

  • Isobel H. Marks
    • 1
    • 2
  • Zhi Ven Fong
    • 1
  • Sahael M. Stapleton
    • 1
  • Ya-Ching Hung
    • 1
  • Yanik J. Bababekov
    • 1
  • David C. Chang
    • 1
    Email author
  1. 1.Department of SurgeryMassachusetts General Hospital/Harvard Medical SchoolBostonUSA
  2. 2.Imperial CollegeLondonUK

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