Table 1 Baseline characteristics prior to smartphone initiation by diagnosis

Age (years)

53.7 (12.2)

54.0 (12.0)

53.0 (12.7)

0.413

Sex (% male)

9.2

9.6

8.5

0.705

Non-Hispanic White (%)

89.77

90.4

88.6

0.558

Married (%)

74.5

73.8

75.8

0.650

Employed (%)

53.1

53.9

51.6

0.655

Education (years)

15.4 (2.2)

15.5 (1.9)

15.2 (2.6)

0.207

Household income (US$1000)

81.5 (40.9)

83.5 (41.0)

77.7 (40.6)

0.160

Number of persons living in household

2.3 (1.1)

2.3 (1.0)

2.4 (1.1)

0.594

Medicare insurance (%)

29.4

29.5

29.2

0.738

HAQ-II (0–3)

0.78 (0.58)

0.75 (0.59)

0.82 (0.56)

0.242

EQ-5D- values

0.75 (0.13)

0.76 (0.13)

0.73 (0.13)

0.037

Physical component score (SF-36)

38.5 (10.7)

39.5 (10.8)

36.7 (10.4)

0.012

Mental component score (SF-36)

48.3 (11.4)

48.7 (11.7)

47.6 (10.8)

0.386

Patient activity score-II (0–10)

3.33 (2.10)

3.11 (2.11)

3.68 (2.02)

0.005

RD comorbidity index (0–9)

2.25 (1.70)

2.14 (1.69)

2.44 (1.72)

0.079

Sleep disturbance (0–10)

4.22 (3.02)

3.93 (3.00)

4.76 (3.00)

0.008

RADAI joint count

7.47 (4.89)

7.69 (5.02)

7.05 (4.63)

0.187

Rural area (%)

14.94

16.32

12.24

0.260

US Region by ZIP code

0.268

 Southeast (%)

32.51

35.27

27.27

 Northeast (%)

12.78

11.64

14.94

 Midwest (%)

36.32

34.25

40.26

 West (%)

18.39

18.84

17.53

 csDMARD use (%)

73.88

 bDMARD use (%)

54.64