Table 1

Patient characteristics of minocycline and doxycycline users and nonusers

Initiated MC/DC (n = 480)

Never used MC/DC (n = 14,309)

P value

Age (years)

58.35 (11.60)

59.76 (13.28)

0.021

Male sex (%)

20.83

22.23

0.469

Rheumatoid arthritis duration (years)

14.77 (10.92)

13.70 (11.05)

0.036

Education (years) (0 to 17)

13.70 (2.32)

13.52 (2.33)

0.106

Caucasian, non-Hispanic (%)

93.68

89.72

0.005

Income (US$)

46,698 (28,088)

46,309 (29,352)

0.775

Semi-annual costs (US$)

6,007 (10,635)

5,685 (7,835)

0.406

Semi-annual drug costs (US$)

4,073 (8,522)

3,826 (6,528)

0.098

Insurance (%)

0.044

Private

29.17

27.26

Health maintenance organization

11.25

8.64

Medicare

41.67

47.10

Preferred provider organization

10.00

9.27

Medicaid

4.79

5.77

No insurance

3.13

1.95

Lifetime DMARDs

2.90 (1.83)

2.13 (1.54)

< 0.001

Lifetime DMARDs and biologics

3.30 (2.10)

2.52 (1.81)

< 0.001

Prednisone (%)

40.08

35.34

0.033

Methotrexate (%)

49.48

50.48

0.667

Comorbidity index (0 to 9)

1.68 (1.46)

1.59 (1.48)

0.193

Health Assessment Questionnaire (0 to 3)

1.06 (0.71)

1.04 (0.73)

0.474

Physical component summary score (0 to 100)

35.03 (11.17)

36.39 (11.09)

0.008

Mental component summary score (0 to 100)

50.02 (11.30)

49.11 (11.49)

0.086

Patient global (0 to 10)

3.47 (2.50)

3.50 (2.53)

0.784

Pain (0 to 10)

3.92 (2.82)

3.83 (2.79)

0.506

Patient Activity Scale (0 to 10)

3.64 (2.27)

3.60 (2.24)

0.666

Data presented as mean (standard deviation). DC, doxycycline; DMARD, disease-modifying anti-rheumatic drug; MC, minocycline.

Smith et al. Arthritis Research & Therapy 2011 13:R168   doi:10.1186/ar3491