| Study period; status | No. of eligible case subjects | No. (%) of case subjects matched | No. of unique control subjects | % of control subjects matched more than once |
|---|---|---|---|---|
| 2005-2008 | ||||
| Alive during study period | 472 468 | 470 620 (99.6) | ||
| Died during study period | 138 611 | 114 354 (82.5) | ||
| Total | 611 079 | 584 974 (95.7) | 549 124 | 6.1 |
| 2009-2012 | ||||
| Alive during study period | 557 878 | 556 349 (99.7) | ||
| Died during study period | 149 636 | 121 977 (81.5) | ||
| Total | 707 514 | 678 326 (95.9) | 646 694 | 4.7 |