Table 3.

SIE hazard estimates at different severity levels of disease controlling for all other variables, using CDAI or HAQ-DI as the measure of disease activity.

Covariate	CDAI		HAQ-DI
Covariate	Adjusted HR (95% CI)	p	Adjusted HR (95% CI)	p
CDAI
Low disease activity	2.715 (1.178–6.258)	0.0191	NA	NA
Moderate disease activity	4.261 (1.870–9.710)	0.0006	NA	NA
High disease activity	4.800 (2.110–10.924)	0.0002	NA	NA
HAQ-DI
0.5–1.0	NA	NA	1.700 (1.119–2.584)	0.0129
> 1.0–2.0	NA	NA	2.508 (1.731–3.633)	< 0.0001
> 2.0–3.0	NA	NA	4.462 (2.990–6.657)	< 0.0001
Disease duration	1.019 (1.009–1.030)	0.0003	1.014 (1.003–1.024)	0.0112
Age at disease onset ≥ 65 yrs	1.289 (0.930–1.785)	0.1269	1.217 (0.879–1.685)	0.2364
Comorbid asthma or COPD	1.925 (1.479–2.505)	< 0.0001	1.767 (1.358–2.298)	< 0.0001
Extraarticular manifestations^*	1.464 (1.147–1.868)	0.0022	1.444 (1.132–1.841)	0.0031
Comorbid conditions^†	2.388 (1.662–3.430)	< 0.0001	2.395 (1.671–3.434)	< 0.0001
Oral corticosteroid dose
< 5 mg/day	1.599 (1.082–2.362)	0.0184	1.680 (1.142–2.471)	0.0084
5–10 mg/day	1.688 (1.277–2.232)	0.0002	1.655 (1.252–2.188)	0.0004
≥ 10 mg/day	2.835 (2.146–3.746)	< 0.0001	2.702 (2.047–3.565)	< 0.0001
Nonbiologic DMARD^††	1.071 (0.810–1.417)	0.6301	1.095 (0.828–1.448)	0.5258
Nonbiologic DMARD^#	0.912 (0.716–1.162)	0.4545	0.947 (0.744–1.205)	0.6589
Biologic DMARD	1.125 (0.897–1.411)	0.3070	1.080 (0.861–1.354)	0.5057
Previous hospitalization due to infection	2.284 (1.661–3.138)	< 0.0001	2.044 (1.486–2.811)	< 0.0001

↵* Classified as associated with RA.
↵† Classified as not associated with RA.
↵†† Classified as posing a significant infection risk.
↵# Classified as not posing a significant infection risk. CDAI: Clinical Disease Activity Index; COPD: chronic obstructive pulmonary disease; DMARD: disease-modifying antirheumatic drug; HAQ-DI: Health Assessment Questionnaire-Disability Index; NA: not applicable; RA: rheumatoid arthritis; SIE: serious infection event.