Risk-adjusted monitoring schemes for surgical performances

Risk-adjusted monitoring schemes for surgical performances

  • Date: 28 August 2021
  • Time: 10:00 am (Bangladesh local time)
  • Speaker: Dr. Ridwan Adeyemi SANUSI, Department of Community Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada


Over the years, different methodologies have been proposed to monitor surgical processes. However, not all the methods are adjusted for risk in the process. For instance, in operating a patient for a coronary artery bypass graft surgery, the outcome X may be recorded as 0 if the patient dies in less than w days (say w=30), or 1 if the patient dies after w days. Statistical schemes that are based on X alone are definitely not risk-adjusted. This is because the surgical outcome of a patient also depends on other conditions of the patient, which can be encapsulated as the predicted risk of death Y. This research proposes some statistical process schemes for monitoring the performance of a surgical operation by adjusting X with the patient’s risk Y. We use a logistic model to estimate Y. The proposed schemes are based on Shewhart and exponentially weighted moving average (EWMA) charts. The Shewhart-type scheme is effective in detecting large shifts, while the EWMA-type scheme is effective in detecting small shifts in the performance of a surgeon. We present an example to show the illustration of the procedures.


Dr. Ridwan Adeyemi SANUSI is a PostDoctoral Fellow at the Centre for Healthcare Innovation, University of Manitoba. He received his Ph.D. from the Department of Systems Engineering and Engineering Management, City University of Hong Kong, Hong Kong. His PhD thesis focused on advanced statistical processing schemes for industrial data. During his PhD program, he was a visiting scholar at the Department of Industrial Engineering, Tsinghua University, Beijing, China. Prior to these, he received his M.Sc. in Applied Statistics from King Fahd University of Petroleum & Minerals, Saudi Arabia, and B.Sc. in Statistics (First Class Honors) from University of Ibadan, Nigeria. He currently has more than ten scientific publications, seven conference presentations, over 200 citations, and few international awards.