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Table 2 Simulation results based on 1000 data sets with sample size of 100 -- Per cent censoring (40%, 25%)

From: Assessing the agreement of biomarker data in the presence of left-censoring

Per cent censoring True ρ True ρ c Method Mean ρ ^ c Relative bias (%) Empirical SD Mean SE The percentage of 95% confidence intervals that include true value of CCC
(40%, 25%) 0.25 0.238 1. Delete the pair 0.1240 −47.90 0.1279 0.1230 84.9
    2. Replace by LOD 0.1929 −18.95 0.1319 0.0843 86.8
    3. Replace by 0.5 × LOD 0.1856 −22.02 0.1092 0.0845 85.9
    4. Replace by c × LOD 0.1850 −22.27 0.1180 0.0844 85.7
    5. ML 0.2340 −1.68 0.0984 0.0971 93.9
  0.50 0.476 1. Delete the pair 0.2754 −42.14 0.1190 0.1108 60.2
    2. Replace by LOD 0.3901 −18.05 0.1219 0.0727 80.1
    3. Replace by 0.5 × LOD 0.3661 −23.09 0.1488 0.0736 73.7
    4. Replace by c × LOD 0.3664 −23.03 0.1603 0.0735 74.0
    5. ML 0.4692 −1.43 0.0847 0.0811 93.8
  0.75 0.714 1. Delete the pair 0.4966 −30.45 0.0978 0.0851 30.7
    2. Replace by LOD 0.6268 −12.21 0.1054 0.0500 68.7
    3. Replace by 0.5 × LOD 0.6055 −15.20 0.1389 0.0512 64.7
    4. Replace by c × LOD 0.6083 −14.80 0.1306 0.0513 65.0
    5. ML 0.7066 −1.04 0.0554 0.0528 94.8
  1. Abbreviations: LLD Lower Limit of Detection, ML Maximum Likelihood, C = Random number from uniform distribution (0, 1), CI, confidence interval, Relative bias = Mean ρ ^ c True ρ c True ρ c ×100%, CCC5= ρ c = 2 COV X , Y VAR X + VAR Y + E X E Y 2 .