Baseline data: demographics, modified comorbidity score and laboratory results
| Year of RA was diagnosed | ||||||
|---|---|---|---|---|---|---|
| 1999–2001 | 2002–2003 | 2004–2005 | 2006–2007 | 2008–2009 | ||
| Patient characteristics | n=3607 | n=2563 | n=2892 | n=2903 | n=1289 | p Value |
| Sex (%) | ||||||
| Male | 89.9 | 89.1 | 90.4 | 90.3 | 88.8 | 0.32 |
| Age (%) | ||||||
| <45 | 11.1 | 7.4 | 6.2 | 5.1 | 6.8 | <0.001 |
| 45–54 | 25.8 | 21.4 | 15.6 | 14.3 | 13.5 | |
| 55–64 | 20.6 | 24.7 | 29.9 | 35.8 | 38.1 | |
| 65–74 | 27.0 | 25.6 | 25.8 | 23.6 | 22.6 | |
| 75 and older | 15.5 | 20.9 | 22.5 | 21.2 | 19.0 | |
| Ethnicity (%) | ||||||
| Caucasian | 74.6 | 78.1 | 79.5 | 77.1 | 78.7 | <0.001 |
| African American | 16.3 | 18.0 | 11.6 | 12.6 | 10.6 | |
| Others* | 5.8 | 5.4 | 4.6 | 4.1 | 3.2 | |
| Unknown | 3.3 | 4.3 | 4.3 | 6.2 | 7.5 | |
| Comorbidity index (%) | ||||||
| 0 | 45.8 | 48.0 | 47.5 | 45.6 | 42.8 | 0.02 |
| 1 | 27.0 | 26.6 | 26.9 | 26.9 | 26.5 | |
| 2 | 11.9 | 11.7 | 11.3 | 12.3 | 12.2 | |
| 3 | 8.0 | 8.2 | 7.3 | 8.0 | 10.6 | |
| 4 or more | 7.3 | 5.5 | 6.5 | 7.3 | 7.9 | |
| Lab results: mean±SD | ||||||
| CRP | 8.6±21.8 | 7.3±22.5 | 7.9±25.1 | 8.7±20.5 | 9.6±20.8 | 0.14 |
| Creatinine | 1.1±0.5 | 1.1±0.5 | 1.1±0.3 | 1.1±0.4 | 1.0±0.3 | <0.001 |
| Haemoglobin | 13.7±1.7 | 13.7±1.6 | 13.8±1.6 | 13.7±1.6 | 13.6±1.6 | 0.90 |
| WBC | 11.2±200 | 8.5±25.4 | 8.0±3.5 | 7.9±2.6 | 16.1±284 | 0.85 |
| ALT | 28.6±21.5 | 28.3±20.0 | 27.1±20.5 | 26.7±17.7 | 25.4±15.3 | <0.001 |
| AST | 24.9±14.1 | 24.1±14.9 | 24.3±13.9 | 24.5±18.4 | 23.6±11.5 | 0.05 |
*Hispanics and Asians.
ALT, alanine aminotransferase; AST, aspartate aminotransferase; CRP, C reactive protein; RA, rheumatoid arthritis; WBC, white blood cell count.