Table 2.
Relationships between socioeconomic status (SES) and clinical and patient‐reported outcomes*
| High‐SES group, reference group (n = 176) | Middle‐SES group (n = 411) | Middle‐ vs. high‐SES group | Low‐SES group (n = 336) | Low‐ vs. high‐SES group | |
|---|---|---|---|---|---|
| Age at onset, years | 6.3 [2.8–10.2] | 6.0 [2.5–10.5] | −0.31 (−1.59, 0.97)a | 7.4 [3.3–11.2] | 1.07 (−0.26, 2.39)a |
| Sex, female | 109 (62) | 261 (64) | 0.93 (0.65, 1.35)b | 211 (63) | 0.96 (0.66, 1.40)b |
| Source of referral | |||||
| Emergency room | 3 (1.7) | 17 (4.3) | 1.01 (−0.25, 2.26)c | 28 (5.6) | 1.96 (0.74, 3.19) sig.c |
| General practitioner | 30 (17.1) | 62 (15.5) | −0.001 (−0.51, 0.50)c | 66 (20.2) | 0.52 (0.004, 1.03) sig.c |
| Orthopedics | 38 (21.7) | 113 (28.3) | 0.36 (−0.09, 0.81)c | 105 (32.1) | 0.75 (0.28, 1.21) sig.c |
| Pediatrician | 87 (49.7) | 180 (45) | Comparator | 114 (34.9) | Comparator |
| Other | 17 (9.7) | 28 (7) | −0.23 (−0.88, 0.43)c | 14 (4.3) | −0.46 (−1.22, 0.30)c |
| Delay to pediatric rheumatologist, months | 5.3 [2.9–12.6] | 5.9 [3.1–12.0] | 0.56 (−0.42, 1.55)a | 5.6 [2.6–11.1] | 0.27 (−0.75, 1.28)a |
| Active joint count | 2 [1–4] | 1 [1–5] | 0 (−2.53, 2.53)a | 2 [1–4] | 0 (−2.61, 2.61)a |
| Limited joint count | 1 [0–3] | 1 [1–3] | 0 (−2.31, 2.31)a | 1 [0–3] | 0 (−2.38, 2.38)a |
| Physician global assessment, mm | 29 [13–53] | 29 [15–51] | 0 (−7.11, 7.11)a | 29 [17–51] | 0 (−7.32, 7.32)a |
| JADAS‐71 | 10.2 [5.8–15.8] | 10.8 [6–18.1] | 0.60 (−2.40, 3.60)a | 12.2 [5.5–16.7] | 2.2 (−0.93, 5.33)a |
| JADAS3‐71 | 10.2 [5.8–15.8] | 10.8 [6–18.1] | −0.30 (−2.39, 1.79)a | 12.2 [5.5–16.7] | 0.80 (−1.39, 2.99)a |
| C‐HAQ score | 0.5 [0–0.875] | 0.625 [0.125–1.375] | 0.37 (0.20, 0.67) sig.d0.10 (−0.11, 0.30)e | 0.875 [0.313–1.625] | 0.28 (0.14, 0.55) sig.d0.26 (0.05, 0.48) sig.e |
| VAS pain, mm | 18.5 [4–48] | 30 [6–56] | 1.08 (0.51, 2.28)d0.20 (0.01, 0.41)e | 39 [13–63.5] | 0.43 (1.16, 1.13)d0.29 (0.07, 0.51) sig.e |
| VAS general evaluation, mm | 15 [4–35] | 20 [3–50] | 1.54 (0.56, 4.20)d0.30 (0.06, 0.54) sig.e | 30 [6–52] | 0.46 (0.11, 1.86)d0.39 (0.14, 0.63) sig.e |
| IPQ | |||||
| Timeline | 15.7 (3.6) | 17.5 (3.4) | 1.73 (0.31, 3.14) sig. | 17.5 (5.1) | 1.75 (0.28, 3.22) sig. |
| Consequences | 16.9 (4.8) | 18.6 (4.8) | 1.68 (0.00, 3.37) | 19.2 (5.1) | 2.32 (0.58, 4.07) sig. |
| Personal control | 18.6 (4.0) | 18.5 (3.7) | −0.13 (−1.63, 1.38) | 18.9 (5.2) | 0.22 (−1.34, 1.78) |
| Treatment control items | 19.9 (1.9) | 18.1 (2.9) | −1.76 (−2.74, −0.77) sig. | 18.5 (3.3) | −1.38 (−2.40, −0.36) sig. |
| Illness coherence items | 17.0 (3.4) | 15.7 (4.5) | −1.24 (−2.76, 0.28) | 15.0 (4.8) | −2.0 (−3.59, −0.45) sig. |
| Timeline cyclical | 12.4 (2.6) | 12.6 (2.9) | 0.19 (−0.81, 1.20) | 12.9 (3.1) | 0.50 (−0.54, 1.54) |
| Emotional representations | 17.9 (4.2) | 19.0 (5.8) | 1.06 (−0.79, 2.91) | 18.7 (5.5) | 0.77 (−1.15, 2.69) |
| CHQ | |||||
| Physical functioning | 11.1 [0–44] | 33 [11–67] | 0.43 (0.23, 0.81) sig.d0.20 (−0.01, 0.43)e | 44 [11–72] | 0.38 (0.19, 0.75) sig.d0.36 (0.11, 0.60) sig.e |
| Role/social limitations–emotional/behavioral | 0 [0–22] | 0 [0–56] | 0.87 (0.50, 1.52)d0.31 (0.06, 0.56) sig.e | 22 [0–67] | 0.66 (0.37, 1.18)0.42 (0.16, 0.69) sig.e |
| Role/social limitations–physical | 17 [0–33] | 33 [0–67] | 16.67 (−26.63, 59.96)a | 50 [0–67] | 33.33 (−12.36, 79.03)a |
| Bodily pain/discomfort | 50 [20–70] | 60 [40–80] | 10 (−16.30, 36.30)a | 60 [40–80] | 10 (−16.63, 36.63)a |
| Behavior | 23 [14–32] | 32 [19–44] | 8.33 (2.79, 13.89) sig.a | 25 [15–44] | 1.67 (−4.15, 7.48)a |
| Mental health | 23 [15–35] | 25 [15–40] | 0 (−13.0, 13.0)a | 25 [15–45] | 0 (−13.4, 13.4)a |
| Self‐esteem | 25 [15–33] | 29 [17–50] | 0.49 (0.15, 1.61)d0.15 (−0.04, 0.34)e | 25 [13–45] | 1.92 (0.72, 5.17)d0.14 (−0.06, 0.34)e |
| Parental impact, emotional | 33 [17–50] | 42 [17–67] | 8.33 (−14.09, 30.75)a | 33 [17–67] | 3.27−e14 (−23.29, 23.29) |
| Parental impact, time | 11 [0–33] | 11 [0–44] | 0.996 (0.57, 1.74)d0.34 (0.08, 0.59) sig.e | 11 [0–44] | 0.71 (0.40, 1.29)d0.24 (−0.02, 0.49)e |
| Family activities | 17 [4–38] | 25 [8–50] | 0.79 (0.39, 1.59)d0.24 (0.01, 0.47) sig.e | 29 [8–50] | 0.58 (0.27, 1.25)d0.24 (0.01, 0.48) sig.e |
| Family cohesion | 15 [15–40] | 15 [15–40] | 0 (−40.64, 40.64)a | 15 [15–40] | 0 (−42.65, 42.65)a |
Values for high‐, middle‐, and low‐SES groups are median [interquartile range] for continuous variables and number (percentage) for categorical variables. Comparison columns include values for β‐coefficent/odds ratio/rate ratio (95% confidence interval). Unless otherwise indicated by a footnote, values are from β‐coefficient linear regression analysis. Sig. = statistically significant at P < 0.05; JADAS‐71 = Juvenile Arthritis Disease Activity Score based on 71 joint count; JADAS3‐71 = JADAS‐71 without erythrocyte sedimentation rate; C‐HAQ = Childhood Health Assessment Questionnaire; VAS = visual analog scale; IPQ = Illness Perception Questionnaire; CHQ = Child Health Questionnaire.
β‐coefficient median regression model.
Odds ratio logistic regression model.
Rate ratio multinominal logistic model.
Odds ratio zero‐inflated part of ZINB model.
β‐coefficient count part of ZINB model.