Table 1.
Characteristics of MIS-C Cases, by Survival Status (n = 2818)—United States, February 2020–March 2021
| Characteristic | No. (%) | Odds Ratio (95% CI) | P Valuec | |||
|---|---|---|---|---|---|---|
| Overall | Survivors | Decedents | Crudea | Adjustedb | ||
| (n = 2818) | (n = 2783) | (n = 35) | ||||
| Sex (n = 2808) | ||||||
| Male | 1664 (59.0) | 1643 (59.0) | 21 (60.0) | 1.0 (0.5–2.0) | 1.0d (0.5–1.9) | .89 |
| Female | 1144 (40.6) | 1130 (40.6) | 14 (40.0) | Ref | Ref | — |
| Age (n = 2811) | ||||||
| <1 y | 98 (3.5) | 97 (3.5) | 1 (2.9) | 1.6 (0.0–12.9) | NA | .98 |
| 1–5 y | 755 (26.8) | 749 (26.9) | 6 (17.1) | 1.3 (0.4–3.8) | 1.3e (0.4–3.8) | .67 |
| 6–11 y | 1112 (39.5) | 1105 (39.7) | 7 (20.0) | Ref | Ref | — |
| 12–15 y | 538 (19.1) | 532 (19.1) | 6 (17.1) | 1.8 (0.6–5.3) | 1.8e (0.6–5.5) | .29 |
| 16–20 y | 308 (10.9) | 293 (10.5) | 15 (42.9) | 8.1 (3.2–20.0) | 6.8f (2.7–17.1) | <.0001 |
| Race/ethnicity (n = 2459) | ||||||
| White, single-race; NH | 681 (27.7) | 676 (27.8) | 5 (16.7) | Ref | Ref | — |
| Black, single-race; NH | 709 (28.8) | 701 (28.9) | 8 (26.7) | 1.5 (0.5–4.7) | 1.2 (0.4–3.9) | .72 |
| Hispanic/Latinog | 909 (37.0) | 897 (36.9) | 12 (40.0) | 1.8 (0.6–5.2) | 1.4 (0.5–4.1) | .54 |
| Asian, single-race; NH | 57 (2.3) | 57 (2.3) | — | NA | NA | .96 |
| AI/AN; Hispanic, NH, or unknown ethnicity | 28 (1.1) | 26 (1.1) | 2 (6.7) | 10.3 (0.9–66.7) | NA | .06 |
| NH/PI; Hispanic, NH, or unknown ethnicity | 29 (1.2) | 27 (1.1) | 2 (6.7) | 9.9 (0.9–64.1) | NA | .06 |
| Multiple races (Black, White, Asian, “other”); NH | 46 (1.9) | 45 (1.9) | 1 (3.3) | 3.0 (0.1–27.6) | NA | .65 |
| Preexisting medical conditions | ||||||
| Any underlying medical conditionh | 1085 (38.5) | 1061 (38.1) | 24 (68.6) | 3.5 (1.7–7.3) | 2.8i (1.4–5.9) | <.01 |
| Obesity | 799 (28.4) | 783 (28.1) | 16 (45.7) | 2.2 (1.1–4.2) | 1.6j (0.8–3.2) | .17 |
| Chronic lung or airway disease | 260 (9.2) | 254 (9.1) | 6 (17.1) | 2.1 (0.9–5.0) | 1.6 (0.6–3.9) | .35 |
| Congenital heart disease | 66 (2.3) | 63 (2.3) | 3 (8.6) | 4.0 (0.8–13.5) | NA | .09 |
| Diabetes mellitus (type 1 or 2) | 26 (0.9) | 24 (0.9) | 2 (5.7) | 7.0 (0.8–30.0) | NA | .08 |
| Immunosuppression/malignancy/autoimmune disorder | 33 (1.2) | 30 (1.1) | 3 (8.6) | 8.6 (1.6–29.9) | NA | .01 |
| Neurologic disorder | 79 (2.8) | 74 (2.7) | 5 (14.3) | 6.1 (2.3–16.2) | 5.1 (1.9–14.1) | <.01 |
| Noncardiac congenital abnormality | 93 (3.3) | 86 (3.1) | 7 (20.0) | 7.8 (3.3–18.5) | 6.5 (2.6–16.0) | <.0001 |
| MIS-C illness | ||||||
| Date of onset (n = 2818) | ||||||
| Before Jun 29, 2020 | 538 (19.1) | 525 (18.9) | 13 (37.1) | 3.8 (1.7–8.7) | 4.2k (1.8–9.6) | <.001 |
| Jun 29–Nov 6, 2020 | 744 (26.4) | 732 (26.3) | 12 (34.3) | 2.5 (1.1–5.8) | 2.5k (1.1–5.8) | .04 |
| Nov 7, 2020–Mar 17, 2021 | 1535 (54.5) | 1525 (54.8) | 10 (28.6) | Ref | Ref | — |
| Days between MIS-C onset and hospital admission, median (IQR) | 4 (2–5) | 4 (2–5) | 3 (0–4) | NA | NA | <.01 |
| Length of hospital stay, median (IQR), d | 6 (4–8) | 6 (4–8) | 6 (2–22) | NA | NA | .82 |
| Maximum temperature, median (IQR), °C | 39.7 (39.3–40.2) | 39.7 (39.3–40.2) | 39.4 (38.9–40.2) | NA | NA | .21 |
| Duration of fever, median (IQR), d | 5 (4–7) | 5 (4–7) | 5 (4–6) | NA | NA | .53 |
| Cardiovascular system involvement | ||||||
| Arrhythmia | 596 (21.1) | 583 (20.9) | 13 (37.1) | 2.2 (1.1–4.5) | 2.2 (1.1–4.3) | .03 |
| Coronary artery dilation or aneurysm (n = 2666) | 421 (15.8) | 420 (15.9) | 1 (3.3) | 0.4 (0.1–1.0) | NA | .05 |
| Myocarditis | 422 (15.0) | 413 (14.8) | 9 (25.7) | 2.0 (0.9–4.3) | 1.5l (0.7–3.3) | .32 |
| Reduced cardiac function | 795 (28.2) | 779 (28.0) | 16 (45.7) | 2.2 (1.1–4.2) | 1.7l (0.9–3.5) | .12 |
| Elevated troponin | 1484 (52.7) | 1466 (52.7) | 18 (51.4) | 1.0 (0.5–1.9) | 0.9l (0.4–7.7) | .66 |
| B-type or NT pro-B-type natriuretic peptide ≥1000 pg/mL | 992 (35.2) | 985 (35.4) | 7 (20.0) | 0.5 (0.2–1.1) | 0.5 (0.2–1.2) | .11 |
| Shock | 1268 (45.0) | 1238 (44.5) | 30 (85.7) | 7.5 (2.9–19.4) | 5.9 (2.3–15.2) | <.001 |
| Severe cardiovascular involvementm | 2301 (81.7) | 2266 (81.4) | 35 (100.0) | 11.4 (2.5–∞) | NA | <.01 |
| Respiratory system involvement | ||||||
| Cough | 816 (29.0) | 796 (28.6) | 20 (57.1) | 3.3 (1.7–6.5) | 2.3l (1.1–4.6) | .02 |
| Pneumonia | 747 (26.5) | 722 (25.9) | 25 (71.4) | 7.1 (3.4–14.9) | 4.8l (2.2–10.2) | <.0001 |
| Acute respiratory distress syndrome | 162 (5.7) | 146 (5.2) | 16 (45.7) | 15.2 (7.7–30.2) | 9.5l (4.6–19.5) | <.0001 |
| Severe respiratory involvementn | 1289 (45.7) | 1255 (45.1) | 34 (97.1) | 41.4 (5.7–302.8) | 27.9l (3.8–205.3) | <.01 |
| Mucocutaneous involvement | ||||||
| Rash | 1571 (55.7) | 1558 (56.0) | 13 (37.1) | 0.5 (0.2–0.9) | 0.7l (0.3–1.4) | .30 |
| Mucocutaneous lesions | 646 (22.9) | 644 (23.1) | 2 (5.7) | 0.2 (0.0–0.8) | NA | .02 |
| Conjunctivitis | 1573 (55.8) | 1570 (56.4) | 3 (8.6) | 0.1 (0.0–0.3) | NA | <.0001 |
| Any mucocutaneous involvemento | 2110 (74.9) | 2095 (75.3) | 15 (42.9) | 0.3 (0.1–0.5) | 0.4 (0.2–0.8) | <.01 |
| Neurologic involvement | ||||||
| Encephalopathy | 76 (2.7) | 71 (2.6) | 5 (14.3) | 6.4 (2.4–16.9) | 5.4 (2.0–14.7) | <.01 |
| Meningitis | 105 (3.7) | 100 (3.6) | 5 (14.3) | 4.5 (1.7–11.8) | 4.7 (1.7–12.8) | <.01 |
| Stroke | 22 (0.8) | 15 (0.5) | 7 (20.0) | 46.1 (17.5–121.9) | 38.1 (13.0–111.1) | <.0001 |
| Severe neurologic involvementp | 179 (6.4) | 167 (6.0) | 12 (34.3) | 8.2 (4.0–16.7) | 7.7 (3.7–16.0) | <.0001 |
| Renal involvement | ||||||
| Acute kidney injury | 535 (19.0) | 518 (18.6) | 17 (48.6) | 4.1 (2.1–8.1) | 2.9 (1.4–6.0) | <.01 |
| Renal failure | 82 (2.9) | 71 (2.6) | 11 (31.4) | 17.5 (8.3–37.1) | 11.7l (5.3–26.0) | <.0001 |
| Severe renal involvementq | 567 (20.1) | 545 (19.6) | 22 (62.9) | 7.0 (3.5–13.9) | 4.8 (2.4–9.8) | <.000 |
| Hematologic involvement | ||||||
| Lymphopenia (age-based)r | 1104 (39.2) | 1092 (39.2) | 12 (34.3) | 0.8 (0.4–1.6) | 0.8 (0.4–1.6) | .46 |
| Platelets <150 000/µL | 1195 (42.4) | 1177 (42.3) | 18 (51.4) | 1.4 (0.7–2.8) | 1.6 (0.8–3.1) | .18 |
| Deep venous thrombosis or pulmonary embolism | 21 (0.7) | 19 (0.7) | 2 (5.7) | 8.8 (1.0–39.0) | NA | .05 |
| Severe hematologic involvements | 1751 (62.1) | 1727 (62.1) | 24 (68.6) | 1.3 (0.7–2.7) | 1.3 (0.6–2.8) | .44 |
| Gastrointestinal involvement | ||||||
| Vomiting or diarrhea | 2245 (79.7) | 2222 (79.8) | 23 (65.7) | 0.5 (0.2–1.0) | 0.5l (0.3–1.1) | .08 |
| Mesenteric adenitis | 330 (11.7) | 327 (11.7) | 3 (8.6) | 0.7 (0.1–2.3) | NA | .8 |
| Free fluid in abdomen or pelvis | 297 (10.5) | 294 (10.6) | 3 (8.6) | 0.8 (0.2–2.6) | NA | .98 |
| Liver failure | 28 (1.0) | 23 (0.8) | 5 (14.3) | 20.0 (7.1–56.1) | 11.2 (3.7–34.1) | <.0001 |
| Severe gastrointestinal involvementt | 721 (25.6) | 711 (25.5) | 10 (28.6) | 1.2 (0.6–2.4) | 1.1 (0.5–2.4) | .74 |
Abbreviations: AI, American Indian; AN, Alaska Native; ECMO, extracorporeal membrane oxygenation; ICU, intensive care unit; IQR, interquartile range; IVIG, intravenous immune globulin; MIS-C, multisystem inflammatory syndrome in children; NA, not applicable; NH, Non-Hispanic; NH/PI, Native Hawaiian/Pacific Islander.
aIf cell size was <5, we calculated unadjusted, exact parameter estimates.
bAdjusted for age (continuous, years), obesity (dichotomous), and MIS-C onset date (continuous, days).
cFor categorical variables, we report chi-square or, if cell size <5, exact P values; for continuous variables we report Kruskal-Wallis P values.
dAdjusted for race/ethnicity (categorical), age (continuous, years), obesity (dichotomous), and MIS-C onset date (continuous, days).
eAdjusted for race/ethnicity (categorical), obesity (dichotomous), and MIS-C onset date (continuous, days).
fAdjusted for race/ethnicity (categorical), obesity (dichotomous), any underlying medical condition other than obesity (dichotomous), and MIS-C onset date (continuous, days).
gOf any race other than AI, AN, NH, PI, or unknown race.
hUnderlying medical conditions included obesity, chronic lung or airway disease, congenital heart disease, type 1 or type 2 diabetes mellitus, immunosuppressive or autoimmune disorders, malignancy, neurologic disorders, noncardiac congenital abnormalities, or sickle cell disease.
iAdjusted for race/ethnicity (categorical), age (continuous, years), and MIS-C onset date (continuous, days).
jAdjusted for race/ethnicity (categorical), age (continuous, years), any underlying medical condition other than obesity (dichotomous), and MIS-C onset date (continuous, days).
kAdjusted for age (continuous, years) and obesity (dichotomous).
lAdjusted for age (continuous, years), obesity (dichotomous), any underlying medical condition other than obesity (dichotomous), and MIS-C onset date (continuous, days).
mSevere cardiovascular system involvement included at least 1 of the following: arrhythmia, cardiac dysfunction (echocardiographic evidence of left or right ventricle dysfunction), congestive heart failure, coronary artery aneurysm or dilation, support using extracorporeal membrane oxygenation, myocarditis, brain or N-terminal pro-brain natriuretic peptide level ≥1000 pg/mL, pericardial effusion, pleural effusion, elevated troponin (above upper limit of normal for the associated laboratory), receipt of vasopressor medications.
nSevere respiratory system involvement included at least 1 of the following: acute respiratory distress syndrome; pleural effusion; pneumonia; ventilatory support using high-flow nasal cannula, noninvasive ventilation, or intubation and mechanical ventilation.
oAny mucocutaneous involvement included at least 1 of the following: conjunctival injection, mucocutaneous lesions, rash.
pSevere neurologic involvement included at least 1 of the following: encephalopathy, meningitis, stroke.
qSevere renal involvement included at least 1 of the following: acute kidney injury, receipt of dialysis, renal failure.
rLymphopenia was defined as lymphocyte level <4500 cells/µL if age <8 months or <1500 cells/µL if age >8 months.
sSevere hematologic involvement included at least 1 of the following: deep vein thrombosis, pulmonary embolism, lymphopenia (lymphocyte level <4500 cells/µL if age <8 months or <1500 cells/µL if age ≥8 months); neutropenia (absolute neutrophil count <500 cells/µL), thrombocytopenia (platelets <150/µL).
tSevere gastrointestinal involvement included at least 1 of the following: appendicitis, radiographically diagnosed enteritis/ileitis/colitis, free fluid in abdomen or pelvis, gallbladder hydrops, hepatomegaly, liver failure, mesenteric adenitis.