Background
Methods
Design, setting, and data sources
Patient sampling strategy
AxSpA classification by chart review
Characterizing the chart-reviewed population and evaluating AS ICD-9 codes
Results
Patient population
Subgroups | Subgroup Criteria (ICD-9 or laboratory data) | No. of Veterans | No. of Veterans selected to chart review population | % from each risk stratum selected to the chart review population (95% CI) |
---|---|---|---|---|
High risk for axSpA | ||||
Ankylosing spondylitis | 720.0 | 15,862 | 100 | 0.83 (0.72–0.96) |
HLA-B27 positivity | positive B27 test result | 8168 | 100 | |
Moderate risk for axSpA | ||||
Sacroiliitis | 720.2 | 50,603 | 100 | 0.25 (0.21–0.28) |
SpA subtype other than AS | 100a | |||
Spondyloarthritis NOS | 720.8× and/or 720.9× | 6319 | ||
Reactive arthritis | 711.x and/or 99.3 | 1072 | ||
Psoriatic arthritis | 696.0 | 22,625 | ||
Enteropathic arthritis | 713.1 AND either 555.x OR 556.x | 521 | ||
Low risk of axSpA | ||||
Chronic back pain | (≥2 ICD-9 codes for back pain ≥3 months apart [724.1, 724.2, 724.5]) | 2,069,644 | 100 | 0.01 (0.01–0.01) |
Non-SpA rheumatologic disease | 100a | |||
DISH | 721.6 | 2963 | ||
Crystal arthritis | 274.x and/or 712.x | 675,799 | ||
Rheumatoid arthritis | 714.x | 143,620 | ||
Other inflammatory arthritis | CTD (710.x), vasculitis (273.2, 446.0, 446.4, 446.5, 446.7), PMR (725), Paget’s (731.0), sarcoidosis (135) | 135,608 |
All | High risk for axSpA | Moderate risk for axSpA | Low risk for axSpA | ||||
---|---|---|---|---|---|---|---|
No. [%] (95% CI) n = 600 | AS No. (95% CI) n = 100 | HLA-B27+ No. (95% CI) n = 100 | Non-AS SpA subtype No. (95% CI) n = 100 | Sacroiliitis No. (95% CI) n = 100 | SpA mimics No. (95% CI) n = 100 | Chronic back pain No. (95% CI) n = 100 | |
Yes AxSpA | 162 [27.0] (23.5–30.7) | 87 (78.8–92.9) | 38 (28.5–48.3) | 27 (18.6–36.8) | 7 (2.9–13.9) | 2 (0.2–7.0) | 1 (0.0–5.5) |
No AxSpA | 409 [68.2] (64.3–71.9) | 4 (1.1–9.9) | 57 (46.7–66.9) | 63 (52.8–72.4) | 89 (81.2–94.4) | 97 (91.5–99.4) | 99 (94.6–100.0) |
Uncertain AxSpA | 29 [4.8] (3.3–6.9) | 9 (4.2–16.4) | 5 (1.6–11.3) | 10 (4.9–17.6) | 4 (1.1–9.9) | 1 (0.0–5.5) | 0 (0.0–3.6) |
Yes axSpA (n = 162) | No axSpA (n = 409) | Uncertain axSpA (n = 29) | |||||||
---|---|---|---|---|---|---|---|---|---|
No./Mean | SD/% | 95% CI | No./Mean | SD/% | 95% CI | No./Mean | SD/% | 95% CI | |
Age | 56.2 | 13.5 | 54.1, 58.3 | 60.0 | 13.2 | 58.7, 61.2 | 58.1 | 14.3 | 52.9, 63.3 |
Gender (Male) | 155 | 95.7 | 91.3, 98.3 | 363 | 88.8 | 85.3, 91.7 | 28 | 96.6 | 82.2, 99.9 |
Race | |||||||||
White | 128 | 79.0 | 71.9, 85.0 | 305 | 74.6 | 70.1, 78.7 | 22 | 75.9 | 56.5, 89.7 |
Black | 18 | 11.1 | 6.7, 17.0 | 63 | 15.4 | 12.0, 19.3 | 4 | 13.8 | 3.9, 31.7 |
Other | 2 | 1.2 | 0.2, 4.4 | 6 | 1.5 | 0.5, 3.2 | 0 | 0.0 | 0.0, 11.9 |
Unknown | 14 | 8.6 | 4.8, 14.1 | 35 | 8.6 | 6.0, 11.7 | 3 | 10.3 | 2.2, 27.4 |
Ethnicity | |||||||||
Non-Hispanic | 144 | 88.9 | 83.0, 93.3 | 367 | 89.7 | 86.4, 92.5 | 27 | 93.1 | 77.2, 99.2 |
Hispanic | 7 | 4.3 | 1.8, 8.7 | 19 | 4.6 | 2.8, 7.2 | 2 | 6.9 | 0.9, 22.8 |
Unknown | 11 | 6.8 | 3.4, 11.8 | 23 | 5.6 | 3.6, 8.3 | 0 | 0.0 | 0.0, 11.9 |
Geographic region | |||||||||
Southeast | 57 | 35.2 | 27.9, 43.1 | 153 | 37.4 | 32.7, 42.3 | 14 | 48.3 | 29.5, 67.5 |
North Atlantic | 35 | 21.6 | 15.5, 28.7 | 84 | 20.5 | 16.7, 24.8 | 7 | 24.1 | 10.3, 43.5 |
Midwest | 30 | 18.5 | 12.9, 25.4 | 68 | 16.6 | 13.2, 20.6 | 2 | 6.9 | 0.9, 22.8 |
Continental | 22 | 13.6 | 8.7, 19.8 | 58 | 14.2 | 11.0, 17.9 | 4 | 13.8 | 3.9, 31.7 |
Pacific | 18 | 11.1 | 6.7, 17.0 | 46 | 11.2 | 8.4, 14.7 | 2 | 6.9 | 0.9, 22.8 |
Duration of active VA system use during study period (years) | 9.3 | 2.0 | 9.0, 9.6 | 8.9 | 2.4 | 8.7, 9.2 | 9.0 | 2.2 | 8.2, 9.8 |
#Provider visits/ year during active system use period | 43.6 | 39.3 | 37.5, 49.6 | 45.9 | 42.6 | 41.7, 50.0 | 25.5 | 27.3 | 15.6, 35.5 |