Table 2a.
Emergency room visit sequential analysis by time of extract using maximized sequential probability ratio test (MaxSPRT)
|
|
Near Real-Time Data Extraction |
1.5 Month Delay Data Extraction |
Final Pull (Nov 2009)α |
|||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Observed | Cumulative |
Cumulative |
||||||||||
| Month | Exposed Days | Outcomes | Expected | RR | LLRβ | Exposed Days | Outcomes | Expected | RR | LLRβ | RR (95% confidence interval) | LLRβ |
|
|
|
|
|
|||||||||
| APR 2009 | 41,910 | 77 | 85.1 | 0.91 | 0 | 45,671 | 101 | 90.4 | 1.12 | 0.599 | ||
| MAY | 96,881 | 188 | 191.5 | 0.98 | 0 | 96,719 | 198 | 191.0 | 1.04 | 0.126 | ||
| JUN | 142,357 | 275 | 279.9 | 0.98 | 0 | 141,913 | 286 | 279.1 | 1.02 | 0.084 | ||
| JUL | 163,380 | 319 | 323.5 | 0.99 | 0 | 198,953 | 404 | 383.5 | 1.05 | 0.536 | ||
| AUG | 252,802 | 494 | 484.2 | 1.02 | 0.098 | 252,606 | 498 | 483.4 | 1.03 | 0.217 | ||
| SEP | 303,901 | 595 | 577.3 | 1.03 | 0.267 | 304,377 | 606 | 578.7 | 1.05 | 0.634 | ||
| OCT | 358,198 | 708 | 677.1 | 1.05 | 0.696 | - | - | - | - | - | 1.05 (0.97–1.12) | 0.696 |
Note: RR - Relative Risk; LLR - Log-likelihood Ratio
α
Nonsequential analysis using final pull.
β
Signal criteria for .05 alpha level of significance is a log-likelihood ratio of 4.3.