Table 1.
Baseline characteristics of propensity score-matched cohort and non-matched cohort.
| Metformin use | Non-matched cohort | Matched cohort | |||
|---|---|---|---|---|---|
| Non-user | Regular user | Non-user | Regular user | Standardized mean difference | |
| n | 46,906 | 132,867 | 46,665 | 46,665 | |
| Sex (%) | 0.007 | ||||
| Men | 21,203 (45.2) | 60,906 (45.8) | 21,126 (45.3) | 20,956 (44.9) | |
| Women | 25,703 (54.8) | 71,961 (54.2) | 25,539 (54.7) | 25,709 (55.1) | |
| Mean age (standard deviation) | 70.1 (11.8) | 66.9 (10.9) | 70 (11.7) | 70 (11.5) | 0.002 |
| Medications (%) | |||||
| Insulin | 1416 (3) | 4027 (3) | 1405 (3) | 1313 (2.8) | 0.012 |
| NSAIDs | 6332 (13.5) | 17,561 (13.2) | 6308 (13.5) | 6128 (13.1) | 0.011 |
| Sulfonylureas | 20,045 (42.7) | 75,912 (57.1) | 20,029 (42.9) | 19,462 (41.7) | 0.025 |
| Paracetamol | 16,399 (35) | 44,243 (33.3) | 16,304 (34.9) | 16,075 (34.4) | 0.010 |
| Chronic conditions (%) | |||||
| Renal failure | 749 (1.6) | 1285 (1) | 730 (1.6) | 662 (1.4) | 0.012 |
| Heart failure | 413 (0.9) | 432 (0.3) | 355 (0.8) | 322 (0.7) | 0.008 |
| Hypertension | 34,459 (73.5) | 95,015 (71.5) | 34,271 (73.4) | 34,516 (74) | 0.012 |
| Stroke | 1784 (3.8) | 2983 (2.2) | 1724 (3.7) | 1605 (3.4) | 0.014 |
| Ischemic heart disease | 1711 (3.6) | 3329 (2.5) | 1662 (3.6) | 1574 (3.4) | 0.010 |
| Tobacco abuse | 290 (0.6) | 1421 (1.1) | 290 (0.6) | 268 (0.6) | 0.006 |
| Lipid disorder | 9542 (20.3) | 29,059 (21.9) | 9527 (20.4) | 9392 (20.1) | 0.007 |
| Total knee replacement (%) | 222 (0.5) | 505 (0.4) | 222 (0.5) | 184 (0.4) | |
| Hazard ratio of total knee replacement (95% confidence interval) | 0.81 (0.67–0.98), P = 0.033 | ||||