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Table 1 Simulation results for the estimation of attributable risk A(.) under proportional hazards, constant baseline hazard (γ=1) with regression parameter β= ln(2) and probability of exposure q=0.5

From: Comparison of methods for estimating the attributable risk in the context of survival analysis

Estimation method

  

n=1,000

n=10,000

 

Time

A(t)

Bias

SEE

SSD

CP

Bias

SEE

SSD

CP

KM

τ/4

0.284

0.001584

0.052440

0.052591

0.949

−0.000011

0.016622

0.016349

0.944

 

τ/2

0.240

0.001496

0.039210

0.039099

0.948

0.000235

0.012434

0.012420

0.944

 

3 τ/4

0.200

0.001100

0.035666

0.035948

0.946

−0.000333

0.011353

0.011354

0.949

 

τ

0.166

0.004047

0.043238

0.053015

0.912

0.001025

0.017251

0.019598

0.943

WKM

τ/4

0.284

0.001594

0.052516

0.052483

0.949

0.000003

0.016613

0.016357

0.946

 

τ/2

0.240

0.001541

0.039144

0.038926

0.950

0.000285

0.012401

0.012398

0.946

 

3 τ/4

0.200

0.001093

0.035402

0.035479

0.953

−0.000286

0.011283

0.011297

0.952

 

τ

0.166

0.002922

0.040635

0.048602

0.902

0.000497

0.016646

0.018245

0.942

COX

τ/4

0.284

0.000977

0.038843

0.038208

0.958

−0.000136

0.012292

0.012206

0.956

 

τ/2

0.240

0.001108

0.033847

0.033524

0.951

0.000006

0.010700

0.010616

0.958

 

3 τ/4

0.200

0.001031

0.029264

0.028893

0.958

−0.000081

0.009237

0.009253

0.954

 

τ

0.166

0.002577

0.027146

0.027753

0.946

0.000148

0.008965

0.009087

0.950

PCH

τ/4

0.284

0.001356

0.038338

0.038248

0.952

−0.000086

0.012120

0.012209

0.953

 

τ/2

0.240

0.001372

0.033380

0.033529

0.948

0.000034

0.010543

0.010608

0.952

 

3 τ/4

0.200

0.001113

0.028804

0.028870

0.957

−0.000081

0.009088

0.009263

0.952

 

τ

0.166

0.001564

0.025811

0.025420

0.961

−0.000154

0.008105

0.008153

0.952

Simpler

0.333

0.000826

0.043356

0.043147

0.952

−0.000209

0.013715

0.013776

0.955

  1. KM nonparametric approach based on Kaplan-Meier estimation for S(t), WKM nonparametric approach based on weighted Kaplan-Meier estimation for S(t), COX semiparametric approach, PCH parametric approach using a piecewise constant hazards model, Simpler simpler approach based on proportion of exposed subjects, Bias sampling mean of the difference between \(\hat {A}(t)\) and A(t), SEE sampling mean of standard error estimate of A(t), SSD sampling standard deviation of \(\hat {A}(t)\), CP coverage probability of the 95% Wald confidence interval