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Table 1 Simulation comparison of VLAD and RA-CUSUM approaches

From: Debate: what is the best method to monitor surgical performance?

Scenario: expected, actual mortality rate Method Proportion of chart exceeding the control limit at patient
10 25 50 75 100 150 200
1: 5 %, 5 % VLAD 0.01 0.02 0.02 0.02 0.03 0.02 0.03
RA-CUSUM 0.00 0.00 0.01 0.01 0.02 0.02 0.03
2: 1 %, 2 % VLAD 0.01 0.08 0.08 0.06 0.14 0.18 0.21
RA-CUSUM 0.00 0.01 0.05 0.08 0.15 0.22 0.32
3: 10 %, 10 % but with 6 deaths in a row patients 94–99 VLAD 0.02 0.02 0.02 0.02 0.32 0.01 0.01
RA-CUSUM 0.00 0.00 0.00 0.01 1.00 0.37 0.22
4: 10 %, 10 % for first 100 patients, then 12.5 % VLAD 0.01 0.01 0.02 0.02 0.02 0.06 0.07
RA-CUSUM 0.00 0.00 0.01 0.01 0.01 0.07 0.12
  1. The bolded values correspond to better performance