Simulation Results

Setup

Proportional hazard models

Equal Event Rates for Historical Data

Setup

  • Event Rate for historical data = 0.3

  • Event Rate for current data = 0.3

  • HR for historical data =0.6

  • HR for current data =0.6

  • Sample size for historical data =800

  • Sample size for current data =900

Tables

##      Time_Int True HR    Est_HR 5%_est_HR 95%_est_HR    cox_HR
## [1,]        1     0.6 0.6122858 0.3541147  0.8809254 0.6127045
## [2,]        2     0.6 0.6330012 0.3567026  0.9287781 0.6332369
## [3,]        3     0.6 0.6253671 0.3778519  0.9327721 0.6255042
## [4,]        4     0.6 0.6353167 0.3693025  1.0257595 0.6356602
## [5,]        5     0.6 0.6403124 0.3756853  1.0513067 0.6404287
## [6,]        6     0.6 0.6383754 0.3599452  1.0510177 0.6388835
## [7,]        7     0.6 0.6436431 0.3387878  1.1428774 0.6438613
## [8,]        8     0.6 0.6475877 0.3237641  1.1580211 0.6478710
##      Est_HR_borrow
## [1,]     0.6189078
## [2,]     0.6178243
## [3,]     0.6116496
## [4,]     0.6434465
## [5,]     0.6439359
## [6,]     0.6293283
## [7,]     0.7116872
## [8,]     0.7109846

Bias

HR estimation

Event rates for current data is greater than the event rates for true/usual (historical) data.

Setup

  • Event Rate for historical data = 0.3

  • Event Rate for current data = 0.4

  • HR for historical data =0.6

  • HR for current data =0.6

  • Sample size for historical data =800

  • Sample size for current data =900

Tables

##      Time_Int True HR    Est_HR 5%_est_HR 95%_est_HR    cox_HR
## [1,]        1     0.6 0.6128024 0.4209642  0.8543661 0.6128577
## [2,]        2     0.6 0.6170422 0.3916010  0.8941404 0.6170642
## [3,]        3     0.6 0.6229371 0.4021110  0.9388623 0.6230421
## [4,]        4     0.6 0.6239814 0.3762303  0.9773094 0.6241219
## [5,]        5     0.6 0.6276665 0.3563083  0.9790538 0.6279829
## [6,]        6     0.6 0.6282223 0.3671664  1.0192130 0.6284702
## [7,]        7     0.6 0.6380099 0.3633080  1.0061365 0.6378667
## [8,]        8     0.6 0.6453266 0.3629871  1.1717160 0.6454285
##      Est_HR_borrow
## [1,]     0.6511256
## [2,]     0.6566096
## [3,]     0.6620958
## [4,]     0.6785797
## [5,]     0.6884598
## [6,]     0.6798808
## [7,]     0.7111417
## [8,]     0.7355108

Bias

HR estimation

Event rates for current data is lower than the event rates for true/usual (historical) data.

Setup

  • Event Rate for historical data = 0.3

  • Event Rate for current data = 0.25

  • HR for historical data =0.6

  • HR for current data =0.6

  • Sample size for historical data =900

  • Sample size for current data =900

Tables

##      Time_Int True HR    Est_HR 5%_est_HR 95%_est_HR    cox_HR
## [1,]        1     0.6 0.6147608 0.3603036  0.9216107 0.6148990
## [2,]        2     0.6 0.6336919 0.3831456  0.9104772 0.6338210
## [3,]        3     0.6 0.6284179 0.3492131  1.0340624 0.6286859
## [4,]        4     0.6 0.6398435 0.3501594  0.9872208 0.6401729
## [5,]        5     0.6 0.6428885 0.3355981  1.1519909 0.6431702
## [6,]        6     0.6 0.6419535 0.3506648  1.1493039 0.6422353
## [7,]        7     0.6 0.6581935 0.3206350  1.1340437 0.6580438
## [8,]        8     0.6 0.6480507 0.3407553  1.1948866 0.6482052
##      Est_HR_borrow
## [1,]     0.6018469
## [2,]     0.6217875
## [3,]     0.6221501
## [4,]     0.6304157
## [5,]     0.6367195
## [6,]     0.6344810
## [7,]     0.7068768
## [8,]     0.6898418

Bias

HR estimation

Non-Proportional hazard models

Equal Event Rates for Historical Data

Setup

  • Event Rate for historical data = 0.3

  • Event Rate for current data = 0.3

  • HR for historical data =0.6, 0.4

  • HR for current data =0.6, 0.4

  • Sample size for historical data = 800

  • Sample size for current data = 900

Tables

##      Time_Int True HR    Est_HR 5%_est_HR 95%_est_HR    cox_HR
## [1,]        1     0.6 0.6152606 0.3743334  0.8940532 0.6155454
## [2,]        2     0.6 0.6287820 0.3632231  0.9121388 0.6289674
## [3,]        3     0.4 0.4163445 0.2398441  0.6802538 0.4166212
## [4,]        4     0.4 0.4243497 0.2176350  0.6902141 0.4246338
## [5,]        5     0.4 0.4215612 0.2128665  0.6568887 0.4220004
## [6,]        6     0.4 0.4272264 0.2294055  0.7260239 0.4275338
## [7,]        7     0.4 0.4348827 0.2158463  0.7481923 0.4354480
## [8,]        8     0.4 0.4380947 0.2207228  0.7858465 0.4386471
##      Est_HR_borrow
## [1,]     0.6305303
## [2,]     0.6174154
## [3,]     0.4092434
## [4,]     0.4359593
## [5,]     0.4310747
## [6,]     0.4242292
## [7,]     0.4839298
## [8,]     0.4855076

Bias

HR estimation

Event rates for current data is greater than the event rates for true/usual (historical) data

Setup

  • Event Rate for historical data = 0.3

  • Event Rate for current data = 0.4

  • HR for historical data =0.6, 0.4

  • HR for current data =0.6, 0.4

  • Sample size for historical data = 800

  • Sample size for current data = 900

Tables

##      Time_Int True HR    Est_HR 5%_est_HR 95%_est_HR    cox_HR
## [1,]        1     0.6 0.6126200 0.4204122  0.8491343 0.6128577
## [2,]        2     0.6 0.6170115 0.3912004  0.8929255 0.6170642
## [3,]        3     0.4 0.4134157 0.2632658  0.6596468 0.4136359
## [4,]        4     0.4 0.4173980 0.2337005  0.6497578 0.4177946
## [5,]        5     0.4 0.4170428 0.2411115  0.6544047 0.4174430
## [6,]        6     0.4 0.4222395 0.2444053  0.7293989 0.4225395
## [7,]        7     0.4 0.4225540 0.2410636  0.6624895 0.4231071
## [8,]        8     0.4 0.4279771 0.2153521  0.7513211 0.4283949
##      Est_HR_borrow
## [1,]     0.6512946
## [2,]     0.6565342
## [3,]     0.4394342
## [4,]     0.4536053
## [5,]     0.4575089
## [6,]     0.4568959
## [7,]     0.4718041
## [8,]     0.4876867

Bias

HR estimation

Event rates for current data is lower than the event rates for true/usual (historical) data

Setup

  • Event Rate for historical data = 0.3

  • Event Rate for current data = 0.25

  • HR for historical data =0.6, 0.4

  • HR for current data =0.6, 0.4

  • Sample size for historical data = 800

  • Sample size for current data = 900

Tables

##      Time_Int True HR    Est_HR 5%_est_HR 95%_est_HR    cox_HR
## [1,]        1     0.6 0.6145611 0.3632412  0.9215783 0.6148990
## [2,]        2     0.6 0.6336000 0.3841654  0.9076384 0.6338210
## [3,]        3     0.4 0.4177965 0.2219271  0.7030201 0.4182304
## [4,]        4     0.4 0.4279517 0.2093290  0.7416046 0.4281818
## [5,]        5     0.4 0.4337324 0.2152692  0.7356100 0.4340914
## [6,]        6     0.4 0.4205821 0.1945044  0.7830199 0.4206936
## [7,]        7     0.4 0.4397731 0.2175672  0.7890023 0.4400914
## [8,]        8     0.4 0.4382504 0.2154793  0.8205759 0.4386800
##      Est_HR_borrow
## [1,]     0.6020445
## [2,]     0.6218248
## [3,]     0.4138462
## [4,]     0.4216697
## [5,]     0.4294380
## [6,]     0.4156622
## [7,]     0.4730854
## [8,]     0.4667589

Bias

HR estimation