Table 2 Adjusted associations (risk ratio, 95% confidence interval) of independent variables with Lyme disease stage (disseminated vs. early stage)

Age (years)

 0 to < 10

1.24 (1.08, 1.42)

1.25 (1.05, 1.48)

1.04 (0.77, 1.39)

0.39 (0.13, 1.21)

2.59 (1.47, 4.57)

2.66 (1.33, 5.35)

 10 to < 20

1.44 (1.28, 1.63)

1.38 (1.16, 1.63)

1.61 (1.24, 2.10)

1.45 (0.83, 2.55)

2.41 (1.26, 4.58)

2.56 (1.23, 5.34)

 20 to < 30

1.21 (1.00, 1.46)

1.16 (0.89, 1.51)

1.41 (0.99, 2.02)

2.01 (0.94, 4.31)

1.54 (0.63, 3.75)

0.31 (0.04, 2.19)

 30 to < 50

1.13 (0.99, 1.29)

0.99 (0.82, 1.21)

1.39 (1.09, 1.77)

1.30 (0.75, 2.24)

0.64 (0.30, 1.36)

1.30 (0.64, 2.65)

 50 to < 70

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

70+

1.14 (0.96, 1.35)

1.13 (0.88, 1.47)

1.08 (0.77, 1.53)

1.00 (0.43, 2.36)

1.57 (0.73, 3.38)

1.20 (0.46, 3.08)

Sex

 Male

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 Female

1.01 (0.93, 1.09)

1.00 (0.89, 1.12)

1.06 (0.90, 1.25)

0.94 (0.55, 1.61)

1.20 (0.83, 1.74)

1.40 (0.88, 2.21)

Race/ethnicity

 White

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 Non-White

1.25 (0.93, 1.67)

1.18 (0.78, 1.80)

1.33 (0.71, 2.49)

NA

0.93 (0.13, 6.57)

2.07 (0.72, 5.98)

Medical assistance

 0% time

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 > 0% to < 50% time

0.97 (0.85, 1.11)

0.94 (0.78, 1.14)

0.87 (0.65, 1.16)

1.03 (0.56, 1.89)

0.85 (0.48, 1.49)

1.66 (0.97, 2.84)

 ≥ 50% time

1.20 (1.05, 1.37)

1.37 (1.15, 1.64)

1.22 (0.93, 1.60)

1.04 (0.47, 2.27)

0.54 (0.24, 1.22)

0.15 (0.02, 1.16)

Primary care contact

 No

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 Yes

0.59 (0.54, 0.64)

0.55 (0.48, 0.63)

0.44 (0.36, 0.54)

0.51 (0.30, 0.86)

0.75 (0.42, 1.34)

0.13 (0.08, 0.20)

Setting of diagnosis

 Outpatient

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 Urgent care

0.22 (0.17, 0.29)

0.22 (0.15, 0.31)

0.12 (0.06, 0.21)

NA

0.47 (0.23, 0.93)

0.027 (0.003, 0.21)

 Emergency

1.04 (0.85, 1.27)

0.73 (0.50, 1.06)

1.49 (1.09, 2.04)

1.30 (0.48, 3.54)

0.87 (0.31, 2.45)

0.51 (0.16, 1.60)

 Inpatient

2.21 (1.98, 2.47)

1.88 (1.49, 2.36)

4.12 (3.30, 5.14)

25.4 (15.22, 42.50)

NA

3.84 (1.59, 9.25)

Season of diagnosis

 Winter (Dec–Feb)

2.19 (1.96, 2.45)

4.54 (3.84, 5.37)

1.45 (1.03, 2.03)

0.78 (0.25, 2.41)

1.17 (0.44, 3.17)

1.25 (0.54, 2.91)

 Spring (March–May)

1.35 (1.18, 1.54)

2.53 (2.10, 3.04)

0.77 (0.57, 1.05)

0.70 (0.25, 1.97)

0.69 (0.34, 1.39)

0.34 (0.11, 1.06)

 Summer (June–Aug)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 Fall (Sept–Nov)

1.46 (1.33, 1.62)

2.75 (2.35, 3.22)

0.84 (0.67, 1.07)

1.31 (0.80, 2.16)

0.75 (0.42, 1.33)

0.92 (0.54, 1.56)

Urban/rural residence

 Rural

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

1.00 (Reference)

 Urban cluster

1.10 (0.99, 1.22)

1.13 (0.97, 1.32)

1.20 (0.95, 1.52)

1.29 (0.70, 2.39)

1.33 (0.83, 2.14)

1.18 (0.66, 2.13)

 Urbanized area

1.09 (0.98, 1.21)

1.09 (0.94, 1.26)

1.11 (0.90, 1.38)

1.42 (0.95, 2.12)

0.95 (0.54, 1.68)

1.32 (0.77, 2.26)