Table 4.
Hazard ratios for dementia for ever versus never users of metformin estimated for each specific year from 1999 to 2005
| Year | Ever users
|
Never users
|
HR | 95% CI | P value | ||
|---|---|---|---|---|---|---|---|
| n | N | n | N | ||||
| Unmatched original cohort | |||||||
| 1999 | 793 | 21033 | 73 | 1335 | 0.562 | (0.442-0.714) | <0.0001 |
| 2000 | 704 | 21309 | 70 | 1473 | 0.588 | (0.460-0.752) | <0.0001 |
| 2001 | 639 | 22089 | 85 | 1726 | 0.514 | (0.410-0.645) | <0.0001 |
| 2002 | 535 | 21624 | 100 | 2110 | 0.485 | (0.392-0.600) | <0.0001 |
| 2003 | 502 | 21997 | 104 | 2411 | 0.511 | (0.414-0.632) | <0.0001 |
| 2004 | 397 | 20430 | 124 | 2873 | 0.456 | (0.373-0.558) | <0.0001 |
| 2005 | 376 | 19247 | 157 | 3748 | 0.507 | (0.420-0.611) | <0.0001 |
| Matched cohort | |||||||
| 1999 | 90 | 2304 | 73 | 1335 | 0.588 | (0.432-0.801) | 0.0008 |
| 2000 | 84 | 2329 | 70 | 1473 | 0.659 | (0.480-0.906) | 0.0101 |
| 2001 | 96 | 2420 | 85 | 1726 | 0.725 | (0.541-0.971) | 0.0309 |
| 2002 | 59 | 2231 | 100 | 2110 | 0.529 | (0.383-0.730) | 0.0001 |
| 2003 | 69 | 2223 | 104 | 2411 | 0.697 | (0.514-0.945) | 0.0200 |
| 2004 | 55 | 2142 | 124 | 2873 | 0.611 | (0.445-0.840) | 0.0024 |
| 2005 | 49 | 2027 | 157 | 3748 | 0.624 | (0.453-0.861) | 0.0041 |
n: incident case number of dementia, N: case number followed
HR: hazard ratio (weighted for propensity score), CI: confidence interval