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Table 1 Clinical characteristics of metformin users stratified by dose, propensity score-matched non-users, and a non-user matched healthy cohort

From: Impact of metformin use among tuberculosis close contacts with diabetes mellitus in a nationwide cohort study

Characteristics

Healthy cohorts (n = 5846)

Metformin nonusers (n = 5846)

p-value*

Metformin users

All (n = 5846)

p-value#

Low cumulative exposure (n = 5587)

High cumulative exposure (n = 259)

Age at index date

  < 45

570 (9.8%)

570 (9.8%)

 

531 (9.1%)

 

506 (9.1%)

25 (9.7%)

 45 to 65

3030 (51.8%)

3028 (51.8%)

 

3067 (52.5%)

 

2916 (52.2%)

151 (58.3%)

  ≥ 65

2246 (38.4%)

2248 (38.5%)

 

2248 (38.5%)

 

2165 (38.8%)

83 (32.0%)

Sex

    

>

  

 Male

2464 (42.1%)

2464 (42.1%)

 

2464 (42.1%)

 

2360 (42.2%)

104 (40.2%)

 Female

3382 (57.9%)

3382 (57.9%)

 

3382 (57.9%)

 

3227 (57.8%)

155 (59.8%)

aDCSI score

  ≥ 3

0 (0%)

1992 (34.1%)

 

2010 (34.4%)

 

1917 (34.3%)

93 (35.9%)

 1 to 2

0 (0%)

2312 (39.5%)

 

2294 (39.2%)

 

2187 (39.1%)

107 (41.3%)

 0

100 (0%)

1542 (26.4%)

 

1542 (26.4%)

 

1483 (26.5%)

59 (22.8%)

 Type 1 DM

0 (0%)

87 (1.5%)

87 (1.5%)

 

80 (1.4%)

7 (2.7%)

 Liver cirrhosis

0 (0%)

23 (0.4%)

23 (0.4%)

 

22 (0.4%)

1 (0.4%)

Coexisting medical condition

 Previous TB history

76 (1.3%)

384 (6.6%)

< 0.001

224 (3.8%)

< 0.001

220 (3.9%)

4 (1.5%)

 COPD

0 (0%)

487 (8.3%)

352 (6.0%)

< 0.001

344 (6.2%)

8 (3.1%)

 Malignancy

0 (0%)

269 (4.6%)

234 (4.0%)

0.115

222 (4.0%)

12 (4.6%)

 Bronchiectasis

0 (0%)

115 (2.0%)

64 (1.1%)

< 0.001

60 (1.1%)

4 (1.5%)

 Transplantation

0 (0%)

2 (0.03%)

5 (0.09%)

0.453

5 (0.1%)

0 (0%)

 HIV/AIDS

0 (0%)

2 (0.03%)

2 (0.03%)

> 0.999

2 (0.04%)

0 (0%)

 Other co-morbidity$

0 (0%)

105 (1.8%)

96 (1.6%)

0.569

92 (1.6%)

4 (1.5%)

 Urban contact area

4084 (69.9%)

3973 (68.0%)

0.027

4035 (69.0%)

0.223

3842 (68.8%)

193 (74.5%)

 Local TB incidence (/100,000 PYs)

58.5 ± 16.1

59.7 ± 15.7

0.888

59.1 ± 15.7

0.035

59.1 ± 15.8

59.2 ± 14.98

 Low income

391 (6.7%)

410 (7.0%)

0.487

426 (7.3%)

0.591

408 (7.3%)

18 (6.9%)

 Medical visits in 3 months

2.4 ± 2.5

3.8 ± 3.2

< 0.001

4.0 ± 2.9

< 0.001

4.0 ± 2.9

4.0 ± 2.6

 Statin users

0 (0%)

1108 (19.0%)

1559 (26.7%)

< 0.001

1482 (26.5%)

77 (29.7%)

 Corticosteroid users

0 (0%)

80 (1.4%)

67 (1.1%)

0.322

64 (1.1%)

3 (1.2%)

 Insulin users

0 (0%)

2284 (39.1%)

2399 (41.1%)

< 0.001

2278 (40.8%)

121 (46.7%)

 Other OHA users

0 (0%)

5211 (89.1%)

5551 (95.0%)

< 0.001

5295 (94.8%)

256 (98.8%)

 Latent TB infection

256 (4.4%)

391 (6.7%)

< 0.001

200 (3.4%)

< 0.001

185 (3.3%)

15 (5.8%)

 IPT

67 (1.1%)

94 (1.6%)

0.032

65 (1.1%)

0.026

60 (1.1%)

5 (1.9%)

Follow-up duration (days)

582.4 ± 226.6

648.7 ± 177.9

< 0.001

637.3 ± 166.1

< 0.001

635.1 ± 167.5

685.7 ± 121.9

Incident TB events

49 (0.8%)

116 (2.0%)

< 0.001

77 (1.3%)

0.006

74 (1.3%)

3 (1.2%)

  1. Abbreviations: aDCSI, adapted Diabetes Complications Severity Index; HIV/AIDS, human immunodeficiency virus/acquired immunodeficiency syndrome; COPD, chronic obstructive pulmonary disease; DM, diabetes mellitus; IPT, early adherent isoniazid preventive therapy; OHA, oral hypoglycemic agents; PY, person-years; TB, tuberculosis
  2. Data are expressed as the number (%) unless otherwise specified
  3. * p value of healthy cohorts vs. metformin nonusers and # p value of metformin users vs. nonusers in paired t test for continuous variables and McNemar test for categorical variables
  4. $ Including pneumoconiosis, psoriasis, rheumatoid arthritis, and ankylosing spondylitis