TABLE 1.

Characteristics of studies included in the meta-analysis.

References	Sample size	Design	Overall age mean ± SD	Outcome	Type of JAK—inhibitor	Regimen of JAK—inhibitor	Regimen of standard of care	Patient category	JAK—inhibitor vs. control n (%)
Kalil et al. (19)	1,033	Double-blind randomized clinical trial	55.4 ± 15.7	(1) Mortality (2) Safety	Baricitinib	4 mg/day for 2 weeks	Placebo	Moderate to severe	515 (49.8%) vs. 518 (50.2%)
Marconi et al. (20)	1,525	Double-blind Randomized clinical trial	57.6 ± 14.1	(1) Mortality (2) Safety	Baricitinib	4 mg/day for 2 weeks	Placebo + standard of care	Moderate to severe	764 (50.1%) vs. 761 (49.9%)
Ely et al. (45)	101	Double-blind randomized clinical trial	58.598 ± 13.788	(1) Mortality (2) Safety	Baricitinib	4 mg/day for up to 14 days or until hospital discharge	Placebo + standard of care	Severe	51 (50.5%) vs. 50 (49.5%)
Wolfe et al. (43)	1,010	Double-blind randomized clinical trial	58.3 ± 14.0	(1) Mortality (2) Safety	Baricitinib + remdesivir	4 mg/day for up to 14 days or until hospital discharge	Dexamethasone + remdesivir + placebo	Moderate to severe	516 (51.1%) vs. 494 (48.9%)
Incyte Corporation (NCT04377620) et al. (40)	211	Double-blind Randomized clinical trial	63.4 ± 12.69	(1) Mortality (2) Safety	Ruxolitinib	5 mg or 1 mg twice daily	placebo + standard of care	Moderate to severe	164(77.7%) vs. 47 (22.3%)
Cao et al. (21)	41	Single-blind Randomized clinical trial	63 ± 7.4	(1) Mortality (2) Safety	Ruxolitinib	5 mg, twice daily for 2 weeks	Placebo (Vitamin C) + standard of care	Severe	20 (48.8%) vs. 21 (51.2%)
Han et al. (44)	432	Double-blind randomized clinical trial	56.5 ± 13.3	(1) Mortality (2) Safety	Ruxolitinib	5 mg twice daily	Placebo tablets 5 mg twice per day for 14 days	Moderate to severe	287 (66.4%) vs. 145 (33.6%)
Guimar aes et al. (22)	289	Double-blind randomized clinical trial	56 ± 14	(1) Mortality (2) Safety	Tofacitinib	10-mg twice daily for 14 days or until hospital discharge	Placebo 10 mg twice daily for up to 14 days + standard of care	Moderate to severe	144 (49.8%) vs. 145 (50.2%)
Singh et al. (46)	25	Double-blind randomized clinical trial	57.32 ± 12.86	(1) Mortality	Nezulcitini	1, 3 10 mg daily for up to 7 days	Placebo inhalation	Moderate to severe	19 (76%) vs. 6 (23%)
D’Alessio et al. (27)	75	Non-randomized clinical trial	67.6 ± 5.1	(1) Mortality	Ruxolitinib	5 mg, twice daily for 7 days, then tapered to 5 mg/day for a total of 10 days	Hydroxychloroquine + lopinavir/ritonavir	Severe	32 (42.6%) vs. 43 (57.4%)
Iastrebner et al. (28)	102	Clinical trial	57.26 ± 11.41	(1) Mortality (2) Safety	Ruxolitinib	5 mg twice daily	Standard of care	Severe	51 (50.0%) vs. 51 (50.0%)
Rodriguez-Garcia et al. (23)	387	Prospective cohort	62.3 ± 14.8	(1) Mortality (2) Safety	Baricitinib	4 mg/day for 5–10 days	Standard of care + corticosteroids	Moderate to severe	117 (30.2%) vs. 270 (69.8%)
Bronte et al. (24)	76	Prospective cohort	73.5 ± 13.8	(1) Mortality	Baricitinib	4 mg, twice daily for 2 days, followed by 4 mg/day for the remaining 7 days	Hydroxychloroquine + lopinavir/ritonavir + supportive care	Severe	20 (26.3%) vs. 56 (73.7%)
Masia et al. (25)	190	Prospective cohort	60.11 ± 3.41	(1) Mortality (2) Safety	Baricitinib	Not available	Standard of care (tocilizumab + corticosteroids)	Severe	95 (50%) vs. 95 (50%)
Abizanda et al. (26)	156	Prospective cohort	68.5 ± 12.4	(1) Mortality	Baricitinib	Not available	Standard of care	Moderate to severe	78 (50%) vs. 78 (50%)
Stanevich et al. (29)	292	Prospective cohort	58.1 ± 13.3	(1) Mortality (2) Safety	Ruxolitinib	5–10 mg/day until oxygen support withdrawal	Dexamethasone for 5– 10 days	Severe	146 (50%) vs. 146 (50%)
Giudice et al. (30)	17	Prospective cohort	63.5 ± 12.5	(1) Mortality (2) Safety	Ruxolitinib	10 mg, twice daily for 14 days	Hydroxychloroquine + supportive care	Severe	7 (41.1%) vs. 10 (58.9%)
Pérez-Alba et al. (32)	197	Retrospective cohort	59.9 ± 14.9	(1) Mortality (2) Safety	Baricitinib	4 mg/day for 2 weeks	Dexamethasone 6 mg/day for 10 days	Moderate to severe	123 (62.4%) vs. 74 (37.6%)
Cantini et al. (34)	191	Retrospective cohort	67 ± 14	(1) Mortality (2) Safety	Baricitinib	4 mg/day for 2 weeks	Hydroxychloroquine + lopinavir/ritonavir	Mild to moderate	113 (59.1%) vs. 78 (40.9%)
Rosas et al. (33)	29	Retrospective cohort	67.8 ± 13.6	(1) Mortality	Baricitinib	4 mg/day for 2 weeks	Standard of care	Moderate to severe	12 (41.3%) vs. 17 (58.7%)
Stebbing et al. (35)	179	Prospective cohort	66 ± 26.6	(1) Mortality (2) Safety	Baricitinib	4 mg/day for 2 weeks	Standard of care	Moderate to severe	37 (20.6%) vs. 142 (79.4%)
Falcone et al. (37)	278	Retrospective cohort	69.92 ± 3.99	(1) Mortality	Baricitinib	Not available	Standard of care	Moderate to severe	40 (14.4%) vs. 238 (85.6%)
Tziolos et al. (36)	369	Retrospective cohort	65.2 ± 13.6	(1) Mortality	Baricitinib	4 mg once a day for up to 14 days or until hospital discharge	Standard of care	severe	193 (52.3%) vs. 176 (47.7%)
Maslennikov et al. (31)	62	Retrospective cohort	64.3 ± 12.5	(1) Mortality (2) Safety	Tofacitinib	10 mg, twice daily on the first day, then 5 mg, twice daily for 4 days	Standard of care	Moderate to severe	32 (51.6%) vs. 30 (48.4%)
Hayek et al. (38)	269	Retrospective cohort	63.92 ± 14.23	(1) Mortality (2) Safety	Tofacitinib	10-mg twice daily for 5 days	Dexamethasone	severe	138 (51.3%) vs. 131 (48.7%)
Singh et al. (39)	50	Retrospective cohort	46.12 ± 13.49	(1) Mortality	Tofacitinib	10 mg, twice daily	Standard of care	severe	25 (50.0%) vs. 25 (50.0%)
Melikhov et al. (41)	522	Prospective cohort	58.62 ± 12.59	(1) Mortality (2) Safety	Tofacitinib	10 mg for 7–14 days	Baricitinib 4 mg for 7–14 days	Mild to severe	320 (61.3%) vs. 202 (38.7%)
Kojima et al. (42)	98	Retrospective cohort	60.68 ± 3.27	(1) Mortality (2) Safety	Tofacitinib	Not available	Baricitinib	Mild to severe	64 (65.3%) vs. 34 (34.7%)

JAK, inhibitor; Janus kinase inhibitor; SD; standard deviation.