Background
Methods
Study design
Measures
Statistical analysis
Results
Prevalence of nr-axSpA overall, by region, and by sex
Total | Latin America | Africa | Europe | Asia |
p Value | |
---|---|---|---|---|---|---|
Overall sample | ||||||
Number of patients | 914 | 26 | 206 | 298 | 384 | |
nr-axSpA, n (%) | 266 (29.10 %) | 5 (19.23 %) | 33 (16.02 %) | 88 (29.53 %) | 140 (36.46 %) | <0.001 |
95 % CI | (26.15–32.05) | (4.05–34.41) | (11.00–21.04) | (24.34–34.72) | (31.64–41.28) | |
Among males | ||||||
Number of patients | 588 | 12 | 116 | 204 | 256 | |
nr-axSpA, n (%) | 169 (28.74 %) | 4 (33.33 %) | 18 (15.52 %) | 57 (27.94 %) | 90 (35.16 %) | <0.001 |
95 % CI | (25.07–32.41) | (6.58–60.08) | (8.91–22.13) | (21.77–34.12) | (29.29–41.02) | |
Among females | ||||||
Number of patients | 326 | 14 | 90 | 94 | 128 | |
nr-axSpA, n (%) | 97 (29.75 %) | 1 (7.14 %) | 15 (16.67 %) | 31 (32.98 %) | 50 (39.06 %) | <0.001 |
95 % CI | (24.77–34.74) | (0.00–20.70) | (8.93–24.41) | (23.42–42.53) | (30.57–47.56) |
Demographic characteristics of patients with nr-axSpA
Total (N = 914) | nr-axSpA (n = 266) | AS (n = 491) | Other IBP (n = 157) |
p Value | |
---|---|---|---|---|---|
Sex | <0.001 | ||||
Male, n (%) | 588 (64.33 %) | 169 (63.53 %) | 350 (71.28 %) | 69 (43.95 %) | |
95 % CI | (61.22–67.44) | (57.74–69.33) | (67.27–75.29) | (36.17–51.73) | |
Female, n (%) | 326 (35.67 %) | 97 (36.47 %) | 141 (28.72 %) | 88 (56.05 %) | |
95 % CI | (32.56–38.78) | (30.67–42.26) | (24.71–32.73) | (48.27–63.83) | |
Sex | <0.001 | ||||
Male, n (row %) | 588 (100.00 %) | 169 (28.75 %) | 350 (59.52 %) | 69 (11.73 %) | |
95 % CI | (25.08–32.41) | (55.54–63.50) | (9.13–14.34) | ||
Female, n (row %) | 326 (100.00 %) | 97 (29.75 %) | 141 (43.25 %) | 88 (26.99 %) | |
95 % CI | (24.78–34.73) | (37.86–48.64) | (22.17–31.82) | ||
Age, years, mean ± SD | 38.68 ± 12.02 | 34.75 ± 10.03 | 39.03 ± 11.38 | 44.26 ± 14.48 | <0.001 |
Race/ethnicity | <0.001 | ||||
White, n (%) | 596 (65.21 %) | 148 (55.64 %) | 335 (68.23 %) | 113 (71.97 %) | |
95 % CI | (62.11–68.30) | (49.66–61.62) | (64.10–72.35) | (64.94–79.01) | |
Asian, n (%) | 116 (12.69 %) | 55 (20.68 %) | 55 (11.20 %) | 6 (3.82 %) | |
95 % CI | (10.53–14.85) | (15.80–25.55) | (8.41–14.00) | (0.82–6.83) | |
Black, n (%) | 12 (1.31 %) | 2 (0.75 %) | 2 (0.41 %) | 8 (5.10 %) | |
95 % CI | (0.57–2.05) | (0.00–1.79) | (0.00–0.97) | (1.65–8.54) | |
Unknown, n (%) | 190 (20.79 %) | 61 (22.93 %) | 99 (20.16 %) | 30 (19.11 %) | |
95 % CI | (18.15–23.42) | (17.87–27.99) | (16.61–23.72) | (12.95–25.27) | |
BMI category | 0.024 | ||||
Underweight, n (%) | 55 (6.02 %) | 12 (4.51 %) | 38 (7.74 %) | 5 (3.18 %) | |
95 % CI | (4.47–7.56) | (2.01–7.01) | (5.37–10.11) | (0.43–5.94) | |
Normal weight, n (%) | 455 (49.78 %) | 150 (56.39 %) | 236 (48.07 %) | 69 (43.95 %) | |
95 % CI | (46.53–53.03) | (50.42–62.36) | (43.64–52.49) | (36.17–51.73) | |
Overweight, n (%) | 279 (30.53 %) | 78 (29.32 %) | 146 (29.74 %) | 55 (35.03 %) | |
95 % CI | (27.53–33.52) | (23.84–34.8) | (25.68–33.79) | (27.56–42.51) | |
Obese, n (%) | 121 (13.24 %) | 24 (9.02 %) | 70 (14.26 %) | 27 (17.20 %) | |
95 % CI | (11.04–15.44) | (5.57–12.47) | (11.16–17.36) | (11.28–23.11) | |
Unknown, n (%) | 4 (0.44 %) | 2 (0.75 %) | 1 (0.20 %) | 1 (0.64 %) | |
95 % CI | (0.01–0.87) | (0.00–1.79) | (0.00–0.60) | (0.00–1.88) | |
Years since CLBP presentation | <0.001 | ||||
Number of patients | 808 | 232 | 435 | 141 | |
Mean ± SD, years | 9.09 ± 9.07 | 6.32 ± 7.61 | 10.91 ± 9.37 | 8.05 ± 9.10 | |
Age of IBP onset | <0.001 | ||||
Number of patients | 908 | 264 | 488 | 156 | |
Mean ± SD, years | 28.8 ± 9.7 | 27.8 ± 7.3 | 27.0 ± 7.7 | 36.2 ± 14.2 |
Africa (n = 33) | Europe (n = 88) | Asia (n = 140) |
p Value | |
---|---|---|---|---|
Sex | 0.609 | |||
Male, n (%) | 18 (54.55 %) | 57 (64.77 %) | 90 (64.29 %) | |
95 % CI | (37.45–71.64) | (54.73–74.82) | (56.30–72.27) | |
Female (%) | 15 (45.45 %) | 31 (35.23 %) | 50 (35.71 %) | |
95 % CI | (28.36–62.55) | (25.18–45.27) | (27.73–43.70) | |
Age, years mean ± SD | 36.67 ± 10.73 | 36.02 ± 10.56 | 33.24 ± 9.26 | 0.035 |
BMI category | 0.21 | |||
Underweight, n (%) | 1 (3.03 %) | 4 (4.55 %) | 7 (5.00 %) | |
95 % CI | (0.00–8.92) | (0.17–8.93) | (1.37–8.63) | |
Normal weight, n (%) | 16 (48.48 %) | 51 (57.95 %) | 81 (57.86 %) | |
95 % CI | (31.32–65.65) | (47.57–68.34) | (49.62–66.09) | |
Overweight, n (%) | 13 (39.39 %) | 19 (21.59 %) | 44 (31.43 %) | |
95 % CI | (22.61–56.17) | (12.94–30.24) | (23.69–39.17) | |
Obese, n (%) | 2 (6.06 %) | 14 (15.91 %) | 7 (5.00 %) | |
95 % CI | (0.00–14.25) | (8.22–23.6) | (1.37–8.63) | |
Unknown, n (%) | 1 (3.03 %) | 0 (0.00 %) | 1 (0.71 %) | |
95 % CI | (0.00–8.92) | – | (0.00–2.12) | |
Years since CLBP presentation | 0.462 | |||
Number of patients | 29 | 74 | 124 | |
Mean ± SD, years | 8.02 ± 10.01 | 6.68 ± 9.33 | 5.67 ± 5.70 | |
Age of IBP onset | 0.115 | |||
Number of patients | 33 | 87 | 139 | |
Mean ± SD, years | 28.4 ± 8.7 | 28.3 ± 6.5 | 27.1 ± 7.3 |
Clinical characteristics of patients with nr-axSpA
Total (N = 914) | nr-axSpA (n = 266) | AS (n = 491) | Other IBP (n = 157) |
p Value | |
---|---|---|---|---|---|
HLA-B27 test results (when available) | <0.001 | ||||
Positive, n (%) | 397 (72.98 %) | 135 (71.43 %) | 250 (82.78 %) | 12 (22.64 %) | |
Negative, n (%) | 147 (27.02 %) | 54 (28.57 %) | 52 (17.22 %) | 41 (77.36 %) | |
Years from IBP to SpA diagnosis | 0.747 | ||||
Number of patients | 179 | 98 | 27 | 54 | |
Mean ± SD, years | 5.40 ± 7.98 | 5.21 ± 7.69 | 6.48 ± 8.53 | 5.19 ± 8.32 | |
Family history of SpA | <0.001 | ||||
Yes, n (%) | 220 (24.07 %) | 70 (26.32 %) | 132 (26.88 %) | 18 (11.46 %) | |
No, n (%) | 650 (71.12 %) | 180 (67.67 %) | 343 (69.86 %) | 127 (80.89 %) | |
Results not available, n (%) | 44 (4.81 %) | 16 (6.02 %) | 16 (3.26 %) | 12 (7.64 %) | |
Family history of SpA (excluding missing) | <0.001 | ||||
Yes, n (%) | 220 (25.29 %) | 70 (28.00 %) | 132 (27.79 %) | 18 (12.41 %) | |
No, n (%) | 650 (74.71 %) | 180 (72.00 %) | 343 (72.21 %) | 127 (87.59 %) | |
NSAID response | 0.125 | ||||
Positive, n (%) | 657 (71.88 %) | 183 (68.80 %) | 358 (72.91 %) | 116 (73.89 %) | |
Negative, n (%) | 231 (25.27 %) | 72 (27.07 %) | 125 (25.46 %) | 34 (21.66 %) | |
Results not available, n (%) | 26 (2.84 %) | 11 (4.14 %) | 8 (1.63 %) | 7 (4.46 %) | |
Most recent CRP value | 0.146 | ||||
Number of patients | 767 | 226 | 421 | 120 | |
Mean ± SD, mg/L | 16.7 ± 26.0 | 15.8 ± 28.2 | 18.2 ± 25.3 | 13.2 ± 23.5 | |
Most recent CRP level | <0.001 | ||||
Not elevated (<3.5 mg/L), n (%) | 219 (23.96 %) | 72 (27.07 %) | 96 (19.55 %) | 51 (32.48 %) | |
Elevated (≥3.5 mg/L), n (%) | 548 (59.96 %) | 154 (57.89 %) | 325 (66.19 %) | 69 (43.95 %) | |
Results not available, n (%) | 147 (16.08 %) | 40 (15.04 %) | 70 (14.26 %) | 37 (23.57 %) | |
Most recent CRP level (excluding missing) | <0.001 | ||||
Not elevated (<3.5 mg/L), n (%) | 219 (28.55 %) | 72 (31.86 %) | 96 (22.80 %) | 51 (42.50 %) | |
Elevated (≥3.5 mg/L), n (%) | 548 (71.45 %) | 154 (68.14 %) | 325 (77.20 %) | 69 (57.50 %) | |
Most recent ESR value | 0.009 | ||||
Number of patients | 846 | 252 | 464 | 130 | |
Mean ± SD, mm/h | 29.0 ± 23.6 | 26.8 ± 23.9 | 31.2 ± 23.6 | 25.3 ± 22.8 | |
Most recent ESR level | <0.001 | ||||
Not elevated (<28 mm/h), n (%) | 482 (52.74 %) | 158 (59.40 %) | 237 (48.27 %) | 87 (55.41 %) | |
Elevated (≥28 mm/h), n (%) | 364 (39.82 %) | 94 (35.34 %) | 227 (46.23 %) | 43 (27.39 %) | |
Results not available, n (%) | 68 (7.44 %) | 14 (5.26 %) | 27 (5.50 %) | 27 (17.20 %) | |
Most recent ESR level (excluding missing) | <0.001 | ||||
Not elevated (<28 mm/h), n (%) | 482 (56.97 %) | 158 (62.70 %) | 237 (51.08 %) | 87 (66.92 %) | |
Elevated (≥28 mm/h), n (%) | 364 (43.03 %) | 94 (37.30 %) | 227 (48.92 %) | 43 (33.08 %) |
Africa (n = 33) | Europe (n = 88) | Asia (n = 140) |
p Value | |
---|---|---|---|---|
Laboratory-confirmed SpA (HLA-B27) | 0.062 | |||
Positive, n (%) | 15 (45.45 %) | 56 (63.64 %) | 61 (43.57 %) | |
Negative, n (%) | 6 (18.18 %) | 10 (11.36 %) | 37 (26.43 %) | |
Results not available, n (%) | 12 (36.36 %) | 22 (25.00 %) | 42 (30.00 %) | |
Laboratory-confirmed SpA (excluding missing) (HLA-B27) | 0.019 | |||
Positive, n (%) | 15 (71.43 %) | 56 (84.85 %) | 61 (62.24 %) | |
Negative, n (%) | 6 (28.57 %) | 10 (15.15 %) | 37 (37.76 %) | |
Family history of SpA | 0.231 | |||
Yes, n (%) | 9 (27.27 %) | 18 (20.45 %) | 43 (30.71 %) | |
No, n (%) | 22 (66.67 %) | 67 (76.14 %) | 86 (61.43 %) | |
Results not available, n (%) | 2 (6.06 %) | 3 (3.41 %) | 11 (7.86 %) | |
Family history of SpA (excluding missing) | 0.125 | |||
Yes, n (%) | 9 (29.03 %) | 18 (21.18 %) | 43 (33.33 %) | |
No, n (%) | 22 (70.97 %) | 67 (78.82 %) | 86 (66.67 %) | |
NSAID response | 0.264 | |||
Positive, n (%) | 22 (66.67 %) | 64 (72.73 %) | 93 (66.43 %) | |
Negative, n (%) | 7 (21.21 %) | 22 (25.00 %) | 42 (30.00 %) | |
Results not available, n (%) | 4 (12.12 %) | 2 (2.27 %) | 5 (3.57 %) | |
Most recent CRP level | 0.214 | |||
Not elevated (<3.5 mg/L), n (%) | 10 (30.30 %) | 21 (23.86 %) | 37 (26.43 %) | |
Elevated (≥3.5 mg/L), n (%) | 18 (54.55 %) | 55 (62.50 %) | 80 (57.14 %) | |
Results not available, n (%) | 5 (15.15 %) | 12 (13.64 %) | 23 (16.43 %) | |
Most recent CRP level (excluding missing) | 0.104 | |||
Not elevated (<3.5 mg/L), n (%) | 10 (35.71 %) | 21 (27.63 %) | 37 (31.62 %) | |
Elevated (≥3.5 mg/L), n (%) | 18 (64.29 %) | 55 (72.37 %) | 80 (68.38 %) | |
Most recent ESR level | <0.001 | |||
Not elevated (<28 mm/h), n (%) | 20 (60.61 %) | 66 (75.00 %) | 69 (49.29 %) | |
Elevated (≥28 mm/h), n (%) | 9 (27.27 %) | 17 (19.32 %) | 66 (47.14 %) | |
Results not available, n (%) | 4 (12.12 %) | 5 (5.68 %) | 5 (3.57 %) | |
Most recent ESR level (excluding missing) | <0.001 | |||
Not elevated (<28 mm/h), n (%) | 20 (68.97 %) | 66 (79.52 %) | 69 (51.11 %) | |
Elevated (≥28 mm/h), n (%) | 9 (31.03 %) | 17 (20.48 %) | 66 (48.89 %) |
Delay from IBP and CLBP to nr-axSpA or AS diagnosis
Patient-reported outcomes in nr-axSpA and AS
Total (N = 686) | nr-axSpA (N = 188) | AS (N = 413) | Other IBP (N = 85) |
p Value | |
---|---|---|---|---|---|
ASDAS score (ESR) | 0.003 | ||||
Number of patients | 619 | 167 | 378 | 74 | |
Mean ± SD | 2.87 ± 1.14 | 2.62 ± 1.17 | 2.97 ± 1.13 | 2.92 ± 1.01 | |
ASDAS score (CRP) | 0.002 | ||||
Number of patients | 559 | 149 | 346 | 64 | |
Mean ± SD | 2.81 ± 1.19 | 2.52 ± 1.21 | 2.93 ± 1.18 | 2.81 ± 1.17 | |
BASDAI | 0.010 | ||||
Number of patients | 681 | 186 | 412 | 83 | |
Mean ± SD | 4.44 ± 2.24 | 4.03 ± 2.32 | 4.56 ± 2.17 | 4.77 ± 2.29 | |
BASFI | <0.001 | ||||
Number of patients | 683 | 187 | 411 | 85 | |
Mean ± SD | 4.09 ± 2.59 | 3.20 ± 2.47 | 4.43 ± 2.57 | 4.38 ± 2.49 | |
BASMI (11-point) | <0.001 | ||||
Number of patients | 575 | 154 | 353 | 68 | |
Mean ± SD | 3.55 ± 2.03 | 2.41 ± 1.54 | 4.09 ± 2.06 | 3.33 ± 1.75 | |
BASMI (3-point) | <0.001 | ||||
Number of patients | 564 | 146 | 347 | 71 | |
Mean ± SD | 2.83 ± 2.19 | 1.62 ± 1.51 | 3.40 ± 2.25 | 2.52 ± 2.03 | |
BASMI (linear function) | <0.001 | ||||
Number of patients | 686 | 188 | 413 | 85 | |
Mean ± SD | 4.44 ± 2.55 | 3.71 ± 2.77 | 4.77 ± 2.38 | 4.47 ± 2.50 |