Table 1 Baseline characteristics of propensity score-matched cohort and non-matched cohort.

From: Metformin use and the risk of total knee replacement among diabetic patients: a propensity-score-matched retrospective cohort study

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