Characteristics of the incident RA and general population cohorts at the first ICU admission in the Winnipeg Regional Health Authority in the interval 2000–2010*. Values are mean (SD) unless otherwise specified.
| Characteristic | General Population Controls, n = 853 | RA, n = 343 | p |
|---|---|---|---|
| Female, n (%) | 482 (56.5) | 223 (65.0) | 0.0068 |
| Age at admission, yrs | 70.3 (11.9) | 67.1 (13.1) | 0.0003 |
| Duration of followup from the index date, yrs | 7.56 (4.9) | 7.43 (4.8) | 0.68 |
| ICU length of stay, days | 4.23 (6.8) | 4.94 (11.1) | 0.088 |
| Hospital length of stay, days | 23.6 (39.6) | 26.4 (41.1) | 0.072 |
| APACHE II Acute Physiology Score | 10.8 (6.9) | 11.0 (6.89) | 0.46 |
| Glasgow Coma Score, median (IQR) | 15 (15–15) | 15 (15–15) | 0.17 |
| Mechanical ventilation, n (%) | 380 (44.5) | 159 (46.4) | 0.57 |
| Vasoactive agents, n (%) | 336 (39.4) | 134 (39.1) | 0.92 |
| Dialysis, n (%) | 34 (4.0 | 9 (2.6) | 0.25 |
| Region of residence, n (%) | |||
| Urban | 548 (64.2) | 225 (65.6) | 0.65 |
| Socioeconomic status, n (%) | 0.36 | ||
| Rural 1, lowest rural | 62 (7.3) | 29 (8.4) | |
| Rural 2 | 66 (7.7) | 21 (6.1) | |
| Rural 3 | 57 (6.7) | 30 (8.7) | |
| Rural 4 | 67 (7.8) | ** | |
| Rural 5, highest rural | 43 (5.0) | 21 (6.1) | |
| Urban 1, lowest urban | 140 (16.4) | 64 (18.6) | |
| Urban 2 | 127 (14.9) | 50 (14.6) | |
| Urban 3 | 129 (15.1) | 44 (12.8) | |
| Urban 4 | 84 (9.8) | 30 (8.7) | |
| Urban 5, highest urban | 64 (7.5) | 34 (9.9) | |
| Not calculated* | 14 (1.6) | ** | |
| Modified Charlson Comorbidity Index, n (%) | |||
| 0 | 162 (19.0) | 46 (13.4) | 0.039 |
| 1 | 217 (25.4) | 90 (26.2) | |
| > 1 to 3 | 327 (38.3) | 134 (39.1) | |
| > 3 | 147 (17.2) | 73 (21.3) |
↵* Note that because of matching on the index date of diagnosis with RA, the cohorts are no longer matched by the time of first ICU admission, and n are smaller here than in Supplementary Table 3 (available online at jrheum.org) as reasons for admission available only in Winnipeg for the period 2000–2010.
↵** Suppressed because of small cell size to protect confidentiality. RA: rheumatoid arthritis; ICU: intensive care unit; APACHE: Acute Physiology and Chronic Health Evaluation; IQR: interquartile range.