Table 4.

Prevalence at rheumatoid arthritis (RA) incidence/ index date and cumulative incidence rate of multimorbidity (2 or more comorbidities), and substantial multimorbidity (5 or more) that developed during follow-up in 209 RF/ACPA negative patients and 388 RF/ACPA positive^† patients.

Outcome	No.(%) of patients prior to RA incidence in RF/ACPA Pos./Neg.	Odds ratio (95% CI) comparing prior events	No. of events after RA incidence date in RF/ACPA Pos./Neg.	Cumulative incidence at 10 years in RF/ACPA Pos. Patients (95% CI) (%)	Cumulative incidence at 10 years in RF/ACPA Neg. Patients (95% CI) (%)	Hazard ratio (95% CI) for RF/ACPA positive vs negative**
Multimorbidity	137 (35.3) / 91 (43.5)	0.71 (0.49, 1.01)	150 / 64	56.2 (50.0 – 63.2)	57.4 (48.1 – 68.3)	1.00 (0.74, 1.36)
Substantial Multimorbidity	12 (3.1) / 17 (8.1)	0.36 (0.15, 0.82)	103 / 64	24.5 (20.2 – 29.7)	31.3 (24.8 – 39.5)	0.83 (0.60, 1.15)

^†RF/ACPA positive was defined as positive for either rheumatoid factor (RF) or anti-cyclic citrullinated peptide antibody (ACPA)

^**adjusted for age, sex, calendar year, smoking and obesity