Table 5.
Characteristics of the Study Population, %
| Characteristic | MAX 00-06 (N=165,527) | TennCare 98-07 (N=20,697) | PAAD/PACE 98-06 (N=18,825) | KPNC 98-07 (N=34,757) | Total (N=239,806) | |
|---|---|---|---|---|---|---|
| Autoimmune disease | RA | 63.9 | 60.8 | 67.0 | 50.0 | 61.3 |
| IBD | 17.1 | 20.3 | 19.3 | 25.2 | 19.1 | |
| PsO | 13.3 | 14.0 | 10.6 | 17.2 | 13.9 | |
| PsA | 3.6 | 2.6 | 2.5 | 6.0 | 3.9 | |
| AS | 1.2 | 1.3 | 0.6 | 1.1 | 1.1 | |
| Year at entry | 1998–1999 | 0.0 | 19.6 | 21.0 | 14.0 | 5.9 |
| 2000–2001 | 13.9 | 22.9 | 20.8 | 15.8 | 15.6 | |
| 2002–2003 | 33.2 | 29.7 | 22.3 | 19.4 | 29.6 | |
| 2004–2005 | 39.0 | 27.8 | 24.0 | 24.0 | 34.2 | |
| 2006–2007 | 14.0 | 0.0 | 12.0 | 26.7 | 14.8 | |
| Sex | Female | 80.5 | 72.4 | 84.5 | 64.4 | 77.1 |
| Age at entry | 0–19 | 2.9 | 4.2 | 0.0 | 3.4 | 2.9 |
| 20–39 | 13.8 | 19.7 | 0.0 | 15.7 | 13.7 | |
| 40–49 | 18.0 | 21.3 | 0.0 | 18.4 | 17.1 | |
| 50–59 | 21.3 | 24.7 | 0.2 | 23.9 | 20.6 | |
| 60–69 | 18.8 | 19.1 | 10.6 | 18.1 | 18.1 | |
| 70+ | 25.1 | 11.2 | 89.4 | 20.6 | 27.5 | |
| Race/ethnicity | African-Am | 17.2 | 13.4 | 6.4 | 7.7 | 14.3 |
| White | 65.2 | 76.4 | 91.3 | 66.7 | 68.4 | |
| Other | 17.6 | 10.3 | 2.2 | 25.7 | 17.3 | |
| Region | Midwest | 22.8 | ...... | . | 0.2 | 14.9 |
| Northeast | 18.9 | ...... | 100.0 | 0.0 | 19.4 | |
| South | 36.0 | 100.0 | . | 0.1 | 33.0 | |
| West | 22.3 | 99.7 | 32.7 | |||
| Residence** | Urban | 72.7 | 48.5 | 88.3 | 98.2 | 76.2 |
| Rural | 27.3 | 51.5 | 11.7 | 1.8 | 23.8 | |
| Charlson-Deyo | 0 | 27.3 | 51.5 | 11.7 | 1.8 | 23.8 |
| Comorbidity Index | 1 | 38.8 | 37.3 | 22.0 | 37.1 | 37.1 |
| 2 | 22.0 | 19.9 | 22.8 | 11.9 | 20.0 | |
| 3+ | 18.2 | 15.7 | 47.2 | 8.9 | 18.3 |
*
Individuals with multiple autoimmune diseases were counted once using the hierarchy AS>PsO>PsA>IBD>RA.
**
Information on urban/rural residence missing for <1% of subjects.