Table:
Characteristic	Routine cohort (cross-sectional)	Inception cohort (longitudinal)
Patients (n)	767	106
Age (years; mean ± SD)	54.1 ± 14.9	50.5 ± 15.6
Sex (% female)	79.9	75.2
Rheumatoid factor (% positive)	55.3	78.1
Disease duration at baseline (mean ± SD)	8.1 ± 10.6 years	11.5 ± 12.5 weeks
Duration of follow up (years; mean ± SD; range)	-	3.2 ± 1.3; 1–7.25
Disease activity characteristics (median [1st;3rd quartile])	At cross-section	At baseline
Swollen joint count (0–28)	3 (1;7)	7 (4;13)
Tender joint count (0–28)	2 (0;6)	8 (3;16)
ESR (mm; normal <20)	23 (14;55)	49 (24;70)
CRP (mg/dl; normal <1.0)	1.1 (0.5;2.7)	5.1 (1.9;17.0)
Patient assessment of pain (mm; 0–100)	37 (19;53)	50 (32;66)
Patient global assessment of activity (mm; 0–100)	37 (18;58)	51 (33;66)
Evaluator global assessment of activity (mm; 0–100)	34 (19;49)	44 (31;58)
HAQ (0–3)	0.875 (0.25;1.5)	0.75 (0;1.5)
Larsen score	-	1 (0;7)
Completeness of data for analysis
Cross-sectional correlation between composite indices (n [%])	767/767 (100)a	105/106 (99.1%)b
Cross-sectional correlation with HAQ scores (n [%])	720/767 (93.9)	104/106 (98.1)b
Discriminant validity, 1-year follow up (n [%])	-	91/100 (91.0%)
Construct validity, 3-year follow upc (n [%])	-	56/80 (70.0%)

Render the table in Markdown format.

| Characteristic | Routine cohort (cross-sectional) | Inception cohort (longitudinal) | 
 | --- | --- | --- | 
 | Patients (n) | 767 | 106 | 
 | Age (years; mean ± SD) | 54.1 ± 14.9 | 50.5 ± 15.6 | 
 | Sex (% female) | 79.9 | 75.2 | 
 | Rheumatoid factor (% positive) | 55.3 | 78.1 | 
 | Disease duration at baseline (mean ± SD) | 8.1 ± 10.6 years | 11.5 ± 12.5 weeks | 
 | Duration of follow up (years; mean ± SD; range) | - | 3.2 ± 1.3; 1–7.25 | 
 | Disease activity characteristics (median [1st;3rd quartile]) | At cross-section | At baseline | 
 | Swollen joint count (0–28) | 3 (1;7) | 7 (4;13) | 
 | Tender joint count (0–28) | 2 (0;6) | 8 (3;16) | 
 | ESR (mm; normal <20) | 23 (14;55) | 49 (24;70) | 
 | CRP (mg/dl; normal <1.0) | 1.1 (0.5;2.7) | 5.1 (1.9;17.0) | 
 | Patient assessment of pain (mm; 0–100) | 37 (19;53) | 50 (32;66) | 
 | Patient global assessment of activity (mm; 0–100) | 37 (18;58) | 51 (33;66) | 
 | Evaluator global assessment of activity (mm; 0–100) | 34 (19;49) | 44 (31;58) | 
 | HAQ (0–3) | 0.875 (0.25;1.5) | 0.75 (0;1.5) | 
 | Larsen score | - | 1 (0;7) | 
 | Completeness of data for analysis |  |  | 
 | Cross-sectional correlation between composite indices (n [%]) | 767/767 (100)a | 105/106 (99.1%)b | 
 | Cross-sectional correlation with HAQ scores (n [%]) | 720/767 (93.9) | 104/106 (98.1)b | 
 | Discriminant validity, 1-year follow up (n [%]) | - | 91/100 (91.0%) | 
 | Construct validity, 3-year follow upc (n [%]) | - | 56/80 (70.0%) |