Table 8

Performance comparison of alternative estimators: variance of risk estimates. Results obtained on average over 100 realizations generated under two different population size scenarios and 3 types of risk map (1 = observed, 2 = smooth, 3 = random). Poisson kriging was conducted with the semivariogram estimated from the underlying risk values (true γR(h)) or the simulated mortality rates. Bold numbers refer to best performances (i.e. the variance of risk estimates is the closest to the true risk variance reported in the first row) outside the ideal case where the true semivariogram of risk is known.

Estimators

WF population

BF population


BREAST CANCER

Scenario 1

Scenario 2

Scenario 3

Scenario 1

Scenario 2

Scenario 3


True risk values

7.891

5.982

7.891

7.891

5.982

7.891

Population-weighted average

5.635

4.560

0.346

8.538

6.881

3.035

Global Empirical Bayes

3.628

1.722

5.178

0.290

0.145

1.026

Local Empirical Bayes

6.571

4.941

5.257

9.364

8.576

5.339

Poisson kriging (true γR(h))

6.792

5.176

5.561

8.156

6.781

4.161

Poisson kriging

6.922

5.093

5.498

8.332

7.044

4.143


CERVIX CANCER


True risk values

0.946

0.596

0.946

0.946

0.596

0.946

Population-weighted average

0.485

0.498

0.055

0.909

0.918

0.422

Global Empirical Bayes

0.474

0.213

0.593

0.132

0.050

0.162

Local Empirical Bayes

0.727

0.538

0.625

3.197

2.059

2.746

Poisson kriging (true γR(h))

0.793

0.599

0.671

0.941

0.910

0.550

Poisson kriging

0.804

0.596

0.607

1.269

1.137

0.690


Goovaerts International Journal of Health Geographics 2005 4:31   doi:10.1186/1476-072X-4-31

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