Table 1 Comparison of demographic and clinical data for RA patients enrolled in the national database by 88 rheumatological units with those from a sample of nine selected units (unit sample) and those from the osteoporosis module subsample

Demography	NDB	Unit sample	OM subsample
No of cases	12 288	3792	1066
Female	77%	79%	79%
Age, in years (mean, SD)	59.6 (12.9)	59.4 (13.1)	59.9 (12.2)
Disease duration, in years (mean, SD)	10.7 (9.7)	10.7 (9.7)	11.5 (10.0)
High disease activity* (score 7–10)	7%	8%	8%
High disease severity† (severe, very severe)	17%	16%	15%
Current DMARD therapy	82%	82%	85%
Complementary current drug therapy	90%	90%	93%
Current glucocorticoid therapy, mg/day
⩽7.5	45.9%	45.6%	50.8%
>7.5	10.4%	9.8%	8.5%
Patient-derived data:
High pain* (score 7–10)	26%	27%	29%
Poor general health* (score 7–10)	24%	25%	27%
low functional capacity‡ (HAQ >1.75)	23%	24%	28%
No of comorbidities (mean, SD)	2.2 (2.0)	2.3 (2.1)	2.4 (2.1)

*Numeric rating scale from 0 = best to 10 = worst. †Categorical five-point scale “asymptomatic”, “light”, “moderate”, “severe”, “very severe”. ‡Measured by the Funktionsfragebogen Hannover (FFbH), a health assessment questionnaire (HAQ)-like, convertible instrument measuring functional limitation in activities of daily living on a scale from 0 to 100.11 DMARD, disease-modifying antirheumatic drug; NDB, national database; OM, osteoporosis module; RA, rheumatoid arthritis.