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. Author manuscript; available in PMC: 2015 Sep 3.
Published in final edited form as: Epidemiol Methods. 2013 Sep;2(1):85–93. doi: 10.1515/em-2013-0007

Table 1.

Summary statistics of the exposure–response parameter estimates for each scenario with exposure intensity distribution 1

True
hazard
ratio
Match ~30 cases per cohort
~100 cases per cohort
Na Meanb Empirical
standard
errorc
Estimated
standard
errord
Relative
efficiencye
(%)
Na Meanb Empirical
standard
errorc
Estimated
standard
errord
Relative
efficiencye
(%)
1 1:01 10,000 1.0000 2.16E–03 2.02E–03 38.7 3,000 1.0000 1.13E–03 1.11E–03 48.1
1:05 10,000 1.0000 1.52E–03 1.48E–03 78.3 3,000 1.0000 8.52E–04 8.45E–04 84.5
1:10 10,000 1.0000 1.43E–03 1.41E–03 88.7 3,000 1.0000 8.20E–04 8.07E–04 91.4
1:15 10,000 1.0000 1.40E–03 1.39E–03 92.6 3,000 1.0000 8.10E–04 7.95E–04 93.5
1:20 10,000 1.0000 1.38E–03 1.38E–03 94.0 3,000 1.0000 8.08E–04 7.88E–04 94.0
Full 10,000 1.0000 1.34E–03 1.34E–03 3,000 1.0000 7.84E–04 7.69E–04
1.005 1:01 10,000 1.0056 5.80E–03 2.63E–03 5.9 3,000 1.0052 1.41E–03 1.37E–03 33.4
1:05 10,000 1.0051 1.71E–03 1.66E–03 68.4 3,000 1.0050 9.59E–04 9.43E–04 72.1
1:10 10,000 1.0051 1.57E–03 1.54E–03 81.4 3,000 1.0050 8.84E–04 8.78E–04 84.9
1:15 10,000 1.0051 1.52E–03 1.49E–03 86.7 3,000 1.0050 8.52E–04 8.54E–04 91.3
1:20 10,000 1.0050 1.49E–03 1.47E–03 90.2 3,000 1.0050 8.58E–04 8.42E–04 89.9
Full 10,000 1.0050 1.41E–03 1.40E–03 3,000 1.0050 8.14E–04 8.05E–04
1.015 1:01 9,782 1.0189 1.50E–02 8.47E–03 1.2 3,000 1.0160 4.15E–03 3.34E–03 5.2
1:05 9,999 1.0158 3.56E–03 3.11E–03 21.6 3,000 1.0152 1.81E–03 1.72E–03 27.3
1:10 10,000 1.0154 2.68E–03 2.49E–03 38.0 3,000 1.0152 1.46E–03 1.43E–03 42.0
1:15 10,000 1.0153 2.40E–03 2.26E–03 47.6 3,000 1.0151 1.31E–03 1.31E–03 51.8
1:20 10,000 1.0153 2.25E–03 2.13E–03 54.1 3,000 1.0151 1.25E–03 1.24E–03 57.8
Full 10,000 1.0151 1.65E–03 1.62E–03 3,000 1.0150 9.46E–04 9.70E–04

Notes:

a

N is the number of parameter estimates with corresponding standard error less than 1 as calculated by the PHREG procedure.

b

Mean is the exponential of the mean of the estimated log hazard ratios.

c

Empirical standard error is the sample standard deviation of the estimated log hazard ratios.

d

Estimated standard error is the mean of the estimated standard errors.

e

Relative efficiency of 1:m sampling was estimated by dividing the empirical variance obtained from the full risk-set analyses by the empirical variance obtained from the m-sampled risk-set analyses.