Table 3.
Diagnostic performance indicators for individual COVID-19 symptoms, existing case definitions, and derived compound symptom combinations by age group for 122 adults and 63 children with household exposure to COVID-19 in Utah and Wisconsin, United States, March–May 2020
| Adults | Children | Differencee | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Specificitya | Sensitivityb | Youden’s indexc | F-1 scored | Specificity | Sensitivity | Youden’s index | F-1 score | Specificity | Sensitivity | |||||||||||
| Value | (95% CI) | Value | (95% CI) | Value | (95% CI) | Value | (95% CI) | Value | (95% CI) | Value | (95% CI) | Value | (95% CI) | Value | (95% CI) | Value | (95% CI)f | Value | (95% CI)f | |
| Individual symptoms | ||||||||||||||||||||
| Upper respiratory | ||||||||||||||||||||
| Nasal congestion or rhinorrhea | 40 | (30, 51) | 91 | (78, 97) | 32 | (17, 44) | 54 | (40, 66) | 63 | (44, 77) | 86 | (58, 100) | 49 | (25, 67) | 55 | (32, 71) | −23 | (− 44, 2) | 6 | (−13, 31) |
| Sore throat | 61 | (50, 72) | 51 | (33, 68) | 12 | (−9, 31) | 41 | (26, 56) | 88 | (74, 96) | 64 | (29, 88) | 52 | (21, 78) | 62 | (35, 82) | −27 | (−43, − 9) | −13 | (− 47, 28) |
| Lower respiratory | ||||||||||||||||||||
| Cough | 68 | (56, 78) | 86 | (71, 94) | 54 | (37, 68) | 65 | (51, 76) | 90 | (77, 96) | 43 | (13, 77) | 33 | (3, 68) | 48 | (18, 75) | −22 | (−39, −5) | 43 | (2, 78) |
| Chest pain | 84 | (74, 91) | 34 | (18, 52) | 18 | (0, 38) | 39 | (22, 57) | 100 | NAr | 14 | (0, 29) | 14 | (0, 29) | 25 | (11, 40) | −16 | (−27, −8) | 20 | (−6, 45) |
| Shortness of breath | 89 | (80, 94) | 29 | (16, 44) | 17 | (2, 34) | 36 | (21, 52) | 98 | (87, 100) | 21 | (0, 56) | 19 | (−2, 56) | 33 | (11, 63) | −9 | (−20, 0) | 7 | (−33, 38) |
| Discomfort while breathing | 95 | (90, 99) | 29 | (13, 48) | 24 | (8, 43) | 41 | (21, 61) | 100 | NA | 14 | (0, 29) | 14 | (0, 29) | 25 | (11, 40) | −5 | (−10, −1) | 14 | (−10, 40) |
| Wheezing | 97 | (91, 99) | 11 | (3, 25) | 8 | (−1, 21) | 19 | (6, 37) | 100 | (100, 100) | 7 | (0, 33) | 7 | (0, 33) | 13 | (6, 18) | −3 | (−9, 0) | 4 | (−18, 18) |
| Neurological | ||||||||||||||||||||
| Headache | 54 | (43, 65) | 86 | (71, 94) | 40 | (24, 53) | 57 | (44, 68) | 80 | (63, 90) | 86 | (63, 100) | 65 | (47, 81) | 67 | (44, 81) | −26 | (−44, −4) | 0 | (−21, 24) |
| Taste and/or smell dysfunction | 95 | (89, 99) | 71 | (51, 85) | 67 | (47, 82) | 78 | (63, 88) | 96 | (84, 100) | 43 | (18, 67) | 39 | (13, 65) | 55 | (29, 76) | −1 | (−8, 10) | 29 | (−3, 58) |
| Constitutional | ||||||||||||||||||||
| Fever or chills | 82 | (72, 89) | 63 | (46, 78) | 45 | (27, 61) | 60 | (46, 73) | 86 | (68, 95) | 64 | (33, 90) | 50 | (14, 78) | 60 | (30, 82) | −4 | (−20, 16) | −1 | (−36, 37) |
| Fatigue | 59 | (47, 70) | 63 | (43, 78) | 22 | (1, 40) | 47 | (32, 61) | 88 | (71, 96) | 50 | (9, 80) | 38 | (1, 72) | 52 | (19, 79) | −29 | (−48, −8) | 13 | (−32, 60) |
| Myalgia | 79 | (69, 87) | 63 | (45, 77) | 42 | (24, 58) | 59 | (44, 71) | 96 | (85, 100) | 43 | (11, 69) | 39 | (10, 64) | 55 | (23, 75) | −17 | (−29, −4) | 20 | (−19, 62) |
| Gastrointestinal | ||||||||||||||||||||
| Diarrhea | 82 | (71, 90) | 40 | (19, 60) | 22 | (0, 43) | 43 | (23, 62) | 76 | (55, 89) | 29 | (8, 60) | 4 | (−24, 37) | 27 | (10, 47) | 6 | (−13, 30) | 11 | (−27, 46) |
| Abdominal pain | 89 | (80, 94) | 37 | (21, 54) | 26 | (8, 44) | 45 | (27, 61) | 88 | (73, 97) | 14 | (0, 57) | 2 | (−17, 39) | 18 | (7, 45) | 1 | (−13, 17) | 23 | (−20, 49) |
| Nausea | 92 | (85, 96) | 17 | (6, 32) | 9 | (−3, 25) | 25 | (10, 43) | 90 | (77, 96) | 21 | (4, 62) | 11 | (−11, 50) | 27 | (9, 57) | 2 | (−8, 15) | −4 | (−48, 23) |
| Existing case definitions | ||||||||||||||||||||
| COVID-19 and respiratory illness surveillance case definitions | ||||||||||||||||||||
| CDC symptom listg | 21 | (13, 32) | 100 | NA | 21 | (13, 32) | 50 | (38, 63) | 45 | (22, 65) | 100 | NA | 45 | (22, 65) | 51 | (29, 68) | −24 | (−50, 6) | NA | NA |
| ARIh | 29 | (19, 41) | 100 | NA | 29 | (19, 41) | 53 | (40, 65) | 55 | (34, 72) | 86 | (58, 100) | 41 | (17, 60) | 50 | (29, 68) | −26 | (−50, 0) | 14 | (0, 38) |
| CSTE combination 1i | 46 | (34, 58) | 97 | (81, 100) | 43 | (30, 55) | 59 | (45, 70) | 80 | (63, 91) | 86 | (43, 100) | 65 | (33, 83) | 67 | (38, 84) | −34 | (− 53, −12) | 11 | (−7, 45) |
| CSTE combination 2j | 36 | (26, 46) | 97 | (84, 100) | 33 | (20, 44) | 54 | (44, 65) | 57 | (43, 70) | 100 | NA | 57 | (43, 70) | 57 | (39, 72) | −22 | (−43, 0) | −3 | (−14, 0) |
| CLIk | 61 | (48, 73) | 91 | (78, 98) | 52 | (36, 66) | 63 | (49, 76) | 82 | (64, 92) | 71 | (20, 95) | 53 | (8, 80) | 61 | (26, 83) | −21 | (−41, 2) | 20 | (−10, 71) |
| ILIl | 86 | (76, 93) | 54 | (37, 70) | 41 | (23, 59) | 58 | (42, 71) | 96 | (85, 100) | 43 | (11, 80) | 39 | (7, 78) | 55 | (20, 85) | −10 | (− 22, 2) | 11 | (−36, 53) |
| Derived compound symptom combinationsm | ||||||||||||||||||||
| Combination 1n | 94 | (88, 98) | 83 | (64, 94) | 77 | (58, 89) | 84 | (70, 92) | 96 | (84, 100) | 57 | (22, 83) | 53 | (17, 81) | 67 | (29, 86) | −2 | (−10, 9) | 26 | (− 10, 64) |
| Combination 2o | 90 | (81, 96) | 86 | (67, 96) | 75 | (56, 87) | 81 | (67, 90) | 96 | (84, 100) | 64 | (38, 85) | 60 | (31, 83) | 72 | (43, 89) | −6 | (−17, 5) | 21 | (−10, 51) |
| Combination 3p | 91 | (82, 96) | 83 | (64, 94) | 74 | (55, 86) | 81 | (66, 90) | 96 | (84, 100) | 64 | (38, 85) | 60 | (31, 83) | 72 | (43, 89) | −5 | (−15, 5) | 19 | (−14, 49) |
| Combination 4q | 94 | (88, 98) | 83 | (64, 94) | 77 | (58, 89) | 84 | (70, 92) | 96 | (84, 100) | 50 | (17, 67) | 46 | (16, 69) | 61 | (30, 80) | −2 | (−10, 9) | 33 | (3, 66) |
aSpecificity is the probability of testing negative when disease is absent
bSensitivity is the probability of testing positive when disease is present
cYouden’s index is defined as sensitivity plus specificity minus 100 (perfect score = 100)
dF-1 score is defined as the harmonic mean of sensitivity and positive predictive value (perfect score = 100)
eDifference in specificity and sensitivity between adults and children
fConfidence intervals are jointly 95%, or 97.5% with a Bonferroni correction
gU.S. Centers for Disease Control and Prevention (CDC) list of symptoms that may indicate COVID-19 infection (https://www.cdc.gov/coronavirus/2019-ncov/symptoms-testing/symptoms.html). This symptom list was last updated on 13 May 2020
hWorld Health Organization (WHO) acute respiratory infection (ARI) definition for community-based respiratory syncytial virus (RSV) surveillance (https://www.who.int/influenza/rsv/rsv_case_definition/en/). Last updated 04 February 2020
iU.S. Council of State and Territorial Epidemiologists (CSTE) original clinical criteria for COVID-19 reporting (https://cdn.ymaws.com/www.cste.org/resource/resmgr/2020ps/interim-20-id-01_covid-19.pdf). This interim position statement (Interim-20-ID-01) was approved on 05 April 2020 and was replaced by Interim-20-ID-02 on 07 August 2020
jU.S. Council of State and Territorial Epidemiologists (CSTE) revised clinical criteria for COVID-19 reporting (https://cdn.ymaws.com/www.cste.org/resource/resmgr/ps/positionstatement2020/interim-20-id-02_COVID-19.pdf). This interim position statement (Interim-20-ID-02) was approved on 07 August 2020 and replaced Interim-20-ID-01
kU.S. Centers for Disease Control and Prevention (CDC) COVID-19-like illness (CLI) definition was used to guide early diagnostic testing strategies from 17 January 2020–08 March 2020 (https://emergency.cdc.gov/han/han00426.asp)
lInfluenza-like illness (ILI) outpatient visit information collected through the U.S. Outpatient Influenza-like Illness Surveillance Network (ILINet) (https://www.cdc.gov/flu/weekly/overview.htm#anchor_1539281266932). This collaborative effort between CDC, state and local health departments, and healthcare providers has been tracking patients with ILI since the 1997–1998 influenza season
mCompound symptom combinations were derived from all symptoms recorded at any time prior to enrollment (and after the index case’s symptom onset date) through the end of the two-week observation period
nCombination 1: Taste and/or smell dysfunction, OR one of the following: shortness of breath, myalgia, or fever or chills
oCombination 2: Taste and/or smell dysfunction or discomfort breathing, OR at least two of the following: shortness of breath, wheezing, or fever/chills
pCombination 3: Taste and/or smell dysfunction, OR at least two of the following: shortness of breath, wheezing, discomfort breathing, or fever/chills
qCombination 4: Taste and/or smell dysfunction, OR shortness of breath and fever/chills
rNA = not applicable