Table 2 Simulation studya. Comparison of exact and estimated person-years
From: Estimating the standardized incidence ratio (SIR) with incomplete follow-up data
Parameter | Mean | Standard deviation | Median | Interquartile range |
|---|---|---|---|---|
Person-years (exact) | 13466.0 | 114.7 | 13467.1 | 13390.0 – 13544.2 |
Person-years (estimated) | 13409.2 | 44.3 | 13408.5 | 13381.4 – 13435.6 |
Person-years (biased, if deaths/migration ignored) | 14905.3 | 31.9 | 14907.2 | 14884.9 – 14926.9 |
Number of events | 10.95 | 3.26 | 11 | 9 – 13 |
Number of deaths or migrants | 179.7 | 179 | 179 | 172 - 188 |
Difference exact – estimated person - years | 56.8 | 116.9 | 58.5 | −21.15 – 134.2 |
Relative difference exact – estimated (in %) | 0.41 | 0.86 | 0.43 | −0.16 – 0.99 |