Table 3.

Hazard ratios for mortality after immune checkpoint inhibitor initiation, comparing pre-existing RA cases (n=87) and matched non-RA comparators (n=203).

	Deaths	Person- months	Incidence rate (95%CI) per 1000 person-months	Unadjusted HR (95%CI)	Multivariable* HR (95%CI)
All patients (co-primary analysis for mortality)
Pre-existing RA cases	60	1,609	37.3 (27.9, 46.7)	1.22 (0.90, 1.65)	1.16 (0.86, 1.57)
Matched comparators	127	4,538	28.0 (23.1, 32.9)	1.0 (Ref)	1.0 (Ref)
RA cases on baseline DMARDs and their comparators
RA cases	33	593	55.6 (36.6, 74.6)	1.66 (1.10, 2.49)	1.43 (0.94, 2.18)
Matched comparators	58	2,175	26.7 (19.8, 33.5)	1.0 (Ref)	1.0 (Ref)
RA cases not on baseline DMARDs and their comparators
RA cases	27	1,015	26.6 (16.6, 36.6)	0.90 (0.58, 1.41)	0.92 (0.59, 1.45)
Matched comparators	69	2,363	29.2 (22.3, 36.1)	1.0 (Ref)	1.0 (Ref)

^*In addition to matching factors of age, sex, calendar year, cancer type, target of ICI, adjusted for smoking pack-years, cancer duration, previous chemotherapy or hormonal therapy, previous radiation, previous stem cell transplant/CAR-T, and continuous Charlson Comorbidity Index.

CAR-T, chimeric antigen receptor T cells; CI, confidence interval; DMARDs, disease-modifying antirheumatic drugs; HR, hazard ratio; ICI, immune checkpoint inhibitor.