Table 1.
Baseline characteristics of the study population*
| Characteristic | Tapering TNFi (n=47) |
Stable TNFi (n=45) |
| Age, years, mean (SD) | 57.6 (12.6) | 57.4 (10.7) |
| Female, no (%) | 25 (53%) | 30 (67%) |
| Time since first swollen joint, years, mean (SD) | 11.9 (6.9) | 10.0 (7.2) |
| Positive for anticitrullinated peptide antibodies, no (%) | 36 (77%) | 35 (78%) |
| Positive for rheumatoid factor, no (%) | 32 (68%) | 28 (62%) |
| Body mass index (kg/m2), mean (SD) | 25.9 (3.4) | 25.8 (5.0) |
| Current smoker, no (%) | 8 (17%) | 10 (22%) |
| Measures of disease activity | ||
| Disease Activity Score†, mean (SD) | 0.8 (0.3) | 0.9 (0.4) |
| Simplified Disease Activity Index‡, mean (SD) | 1.1 (1.0) | 1.9 (2.3) |
| Simplified Disease Activity Index‡remission, no (%) | 45 (96%) | 34 (76%) |
| ACR/EULAR remission§, no (%) | 38 (81%) | 30 (67%) |
| Swollen joint count¶, mean (SD) | 0.0 (0.0) | 0.0 (0.0) |
| Tender joint count (Ritchie Articular Index)**, mean (SD) | 0.1 (0.2) | 0.2 (0.5) |
| ESR, mm/hour††, normal value <17 mm/hour in women and <12 mm/hour in men, median (IQR) | 7.0 (5.0–14.0) | 8.0 (5.0–15.0) |
| CRP, mg/dL‡‡, normal value <0.4 mg/dL, median (IQR) | 0.1 (0.1–0.3) | 0.1 (0.1–0.2) |
| Patient’s global assessment (0–100)§§, median (IQR) | 3.0 (1.0–12.0) | 2.0 (1.0–12.0) |
| Physician’s global assessment (0–100)§§, median (IQR) | 0.0 (0.0–2.0) | 0.0 (0.0–2.0) |
| Functional outcomes | ||
| PROMIS Physical Function¶¶, median (IQR) | 52.6 (49.0–62.5) | 51.2 (44.2–62.5) |
| Fatigue Visual Analogue Scale (0–100 mm)***, median (IQR) | 7.0 (1.0–22.0) | 3.0 (0.0–31.0) |
| Pain Visual Analogue Scale (0–100 mm)***, median (IQR) | 4.0 (2.0–11.0) | 3.0 (1.0–11.0) |
| Radiographic joint damage | ||
| Total van der Heijde modified Sharp Score†††, median (IQR) | 6.5 (1.5–12.0) | 5.0 (1.5–13.5) |
| van der Heijde Sharp Erosion, median (IQR) | 2.5 (1.0–5.0) | 2.0 (0.5–5.0) |
| van der Heijde Sharp Joint Space Narrowing, median (IQR) | 2.5 (0.5–7.0) | 1.0 (0.0–10.5) |
| Ultrasound outcomes‡‡‡ | ||
| Total power Doppler Signal Score, median (IQR) | 0.0 (0.0– 0.0) | 0.0 (0.0–0.0) |
| Total Grey Scale Score, median (IQR) | 1.0 (0.0–3.0) | 1.0 (0.0–3.0) |
| No power Doppler signal in any joint | 44 (94%) | 42 (96%) |
| Medication | ||
| Etanercept, no (%) | 20 (43%) | 20 (44%) |
| Certolizumab pegol, no (%) | 14 (30%) | 15 (33%) |
| Golimumab, no (%) | 1 (2%) | 4 (9%) |
| Infliximab, no (%) | 9 (19%) | 0 (0%) |
| Adalimumab, no (%) | 3 (6%) | 6 (13%) |
| Co-medication with csDMARDs, no (%) | 42 (89%) | 41 (91%) |
| Co-medication with methotrexate, no (%) | 38 (81%) | 38 (84%) |
*As allocated and initiated treatment. Seven patients who were randomised but did not have verified initiation of treatment were excluded, five from the tapering group and two from the stable group.
†Disease Activity Score (DAS, range 0–10) includes a 44 swollen joint count (SJC44), assessment of tender joints by Ritchie Articular Index (RAI), the ESR and patient’s global assessment (PGA) of disease activity on a VAS 0–100 mm. It is calculated as follows: DAS=0.54*square root(RAI) + 0.065*(SJC44+0.33*Ln(ESR) + 0.0072*PGA. Remission is defined as any value below 1.6, low disease activity 1.6–2.4, moderate disease activity >2.4–3.7, and high disease activity >3.7, thus higher scores indicating more disease activity.
‡Simplified Disease Activity Index (SDAI, range 0–86) includes a 28 swollen (SJC28) and tender joint count (TJC28), CRP, PGA and the physician’s global assessment of disease activity (PhGA) on a VAS 0–100 mm. It is calculated as follows: SDAI=TJC28 + SJC28 + PGA/10+PhGA/10+CRP. Remission is defined as a score ≤3.3, with higher scores indicating more disease activity.
§ACR/EULAR remission is defined as tender joint count ≤1 and swollen joint count ≤1 and CRP ≤1 mg/dL and patient global assessment ≤10 (on a 0–100 scale).
¶The swollen joint count is the number of swollen joints out of 44 joints assessed.
**The tender joint count is performed by the Ritchie Articular Index assessing tenderness of 26 joint regions, the index ranges 0–3 for individual measures and the sum 0–78 overall, with higher scores indicating more tenderness.
††At the time of baseline visit, normal values may vary among laboratories.
‡‡At the time of baseline visit, normal values may vary among laboratories. To convert CRP to mg/L (SI unit), multiply by 10.
§§The patient’s and physician’s global assessments are self-reported and physician-reported, respectively, overall assessments of disease with use of a VAS that ranges 0–100 mm, with higher scores indicating more severe disease.
¶¶PROMIS 20-item short form range 0–100, with scores lower than 50 indicating disability worse than average.
***Fatigue and joint pain are self-reported with use of a VAS ranging 0–100 mm, with higher scores indicating more severe fatigue.
†††van der Heijde modified Sharp scoring method assesses erosions in 16 joints of each hand (range 0–5 for each joint) and 6 joints of each foot (range 0–10 per joint), and joint space narrowing in 15 joints for each hand, as well as six joints for each foot (range 0–4 per joint). This gives scores for erosions on a scale of 0–280 and joint-space narrowing on a scale of 0–168, thus the total van der Heijde Sharp score range is 0–448 with higher scores indicating greater joint damage.
‡‡‡Two aspects of synovitis can be assessed by ultrasound; morphology and quantity using grey scale and synovial vascularity using power Doppler. The ultrasound examination was performed using 0–3 semiquantitative scoring systems for both grey scale and power Doppler in 32 joints.
ACR, American College of Rheumatology; CRP, C reactive protein; csDMARDs, conventional synthetic disease-modifying antirheumatic drugs; DAS, Disease Activity Score; ESR, erythrocyte sedimentation rate; EULAR, European Alliance of Associations for Rheumatology; PROMIS, Patient-reported Outcomes Measurement Information Score; TNFi, tumour necrosis factor inhibitor; VAS, Visual Analogue Scale.