Characteristics at 10 years and median change from baseline, stratified by cohort
| Cohort 1 (1990–1994) | Cohort 2 (2000–2004) | Median difference/OR/relative difference (95% CI)* | Median difference/OR/ relative difference (95% CI)† | |||
| N | Median (IQR) | N | Median (IQR) | |||
| Age at 10-year assessment (years) | 607 | 62 (51–72) | 340 | 66 (56–75) | 4.00 (1.55 to 6.45) | – |
| Gender (n (%) female) | 422 (69.5) | 238 (70.0) | OR 1.02 (0.77 to 1.37) | – | ||
| Swollen joint counts (51) | 601 | 1 (0–4) | 340 | 0.5 (0.0–2.5) | −36% (−49% to −20%) | −33% (−47% to −15%) |
| Median change from baseline | 601 | −4 (−10 –−1) | 340 | −2 (−6– 0) | ||
| Tender joints counts (51) | 601 | 2 (0–11) | 340 | 2 (0–8) | −5% (−24% to 19%) | 2% (−20% to 30%) |
| Median change from baseline | 601 | −3 (−11–1) | 340 | −1 (−6–2) | ||
| HAQ | 597 | 0.88 (0.25–1.63) | 336 | 1.00 (0.25–1.88) | 0.01 (−0.18 to 0.20) | −0.01 (−0.16 to 0.14) |
| Median change from baseline | 588 | 0.13 (−0.25–0.75) | 330 | 0.00 (−0.38–0.63) | ||
| Current sDMARDs use, n (%) | 195 (32.1) | 209 (61.5) | OR 3.35 (2.53 to 4.43) | OR 2.71 (1.91 to 3.86) | ||
*Quantile/logistic/negative binomial regression was used to compare the two cohorts on each variable depending on the type of variable. Regressions comparing SJC, TJC, HAQ and current DMARD use between cohorts controlled for age and gender. Cohort 1 is the reference category.
†Quantile/logistic/negative binomial regression used to compare SJC, TJC, HAQ and number on sDMARDs between cohorts at 10 years. These models controlled for baseline: age, gender, symptom duration before baseline, smoking status, SJC (51), TJC (51), RF, anti-CCP, CRP, HAQ score and being on sDMARDs/steroids. Cohort 1 is the reference category.
anti-CCP2, anticyclic citrullinated protein antibodies; CRP, C reactive protein; DMARD, disease-modifying antirheumatic drug; HAQ, Health Assessment Questionnaire; n, number of patients with available data; sDMARD, synthetic disease-modifying antirheumatic drug; SJC, swollen joint count; TJC, tender joint count.