TABLE 1.

Subgroup analysis of COVID‐19 related mortality in controlled and uncontrolled studies

		Studies with control				Uncontrolled studies
Variables	Subgroup	N	Pooled OR	95% CI	I 2 (%)	N	Pooled prevalence	95% CI	I 2 (%)
Setting	Hospitalized	9	1.91	1.5–2.3	18	44	0.34	0.29–0.39	91
	Mix	5	2.32	1.7–3.0	48	21	0.24	0.20–0.28	89
	Outpatients	‐	‐	‐	‐	2	0.18	0.03–0.32	0
Study design a	Cohort retrospective	8	1.80	1.7–1.9	0	38	0.33	0.26–0.39	97
	Cohort prospective	‐	‐	‐	‐	2	0.36	0.28–0.44	0
	Case‐control	6	2.58	1.9–3.4	32	6	0.29	0.16–0.42	78
Hematological malignancy a	Hematopoietic cell transplantation	‐	‐	‐	‐	7	0.21	0.07–0.36	79
	Mix	13	2.14	1.8–2.6	51	31	0.36	0.31–0.41	88
	Leukemia	1	0.50	0.1–3.8	0	4	0.23	0.12–0.34	82
	Myeloma	‐	‐	‐	‐	5	0.26	0.01–0.51	98
	Myeloproliferative neoplasm	‐	‐	‐	‐	2	0.48	0.37–0.58	0
	Lymphoma	‐	‐	‐	‐	5	0.30	0.25–0.34	8

^a Only studies reporting hospitalized patients were included in this analysis.