Table 3.

Sensitivity, specificity, and TPC for the clinically and data-inferred combinations of symptoms, computed on the held-out validation dataset

			Three-day analysis						Seven-day analysis
			Sensitivity (%)		Specificity (%)		TPC		Sensitivity (%)		Specificity (%)		TPC
	Symptom	Age group	UK	US	UK	US	UK	US	UK	US	UK	US	UK	US
Clinically inferred symptoms	Respiratory symptoms1	All	46.4	48.1	81.9	76.6	42	21	58.1	64.6	79.1	72.3	37	19
		[18–54]	47.1	45.2	81.6	76.8	37	20	58.5	64.3	78.5	71.6	33	18
		[55+]	44.3	51.4	82.5	76.5	60	22	56.7	64.9	80.4	73.0	51	20
	WHO defined pneumonia2	All	59.8	74.7	71.7	59.5	51	23	71.4	84.8	68.4	54.5	46	23
		[18–54]	59.9	69.0	71.0	61.3	46	22	70.7	83.3	67.4	55.5	42	21
		[55+]	59.5	81.1	73.2	57.8	68	24	73.9	86.5	70.6	53.6	59	25
	C-19-specific symptoms3	All	69.0	79.7	69.6	57.6	47	23	83.7	92.4	66.2	52.6	42	22
		[18–54]	69.5	73.8	68.8	59.5	42	22	84.4	92.9	65.1	53.8	37	20
		[55+]	67.2	86.5	71.4	55.7	64	24	81.3	91.9	68.7	51.4	57	25
	Extended symptoms4	All	92.0	96.2	25.9	21.1	85	35	96.7	98.7	22.9	17.9	81	35
		[18–54]	92.6	95.2	25.0	22.2	76	32	96.6	100.0	21.7	18.6	72	32
		[55+]	90.1	97.3	27.9	20.1	120	38	97.0	97.3	25.6	17.3	112	39
Data-inferred subsets	Combination with highest sensitivity5	All	96.3	96.2	11.9	9.8	96	40	99.2	98.7	10.4	8.2	92	39
		[18–54]	96.9	95.2	10.4	8.0	85	38	99.4	100	8.8	6.6	80	36
		[55+]	94.4	97.2	15.2	11.6	141	42	98.5	97.3	13.7	9.8	134	90
	Combination with sensitivity ~ 90%6	All	92.2	96.2	22.4	15.6	89	36	94.7	96.2	37.8	29.3	68	31
		[18–54]	92.7	95.2	21.5	19.2	78	33	93.2	100	37.1	31.3	59	27
		[55+]	91.3	97.3	23.9	17.9	131	39	97.7	97.3	26.8	18.8	115	38
	Combination with specificity ~ 50%7	All	76.4	84.8	40.9	40.0	72	30	87.3	91.1	49.2	38.9	59	29
		[18–54]	76.5	80.9	48.0	42.5	63	28	88.7	92.9	49.6	39.9	50	25
		[55+]	79.3	89.2	49.0	37.8	101	32	82.3	89.2	50.7	37.9	92	32

¹Cough, dyspnoea;

²Cough, dyspnoea, fever;

³Fever, cough, dyspnoea, and anosmia/ageusia;

⁴Fever, cough, dyspnoea, anosmia/ageusia, fatigue, and headache;

⁵Fatigue, anosmia/ageusia, persistent cough, diarrhoea, headache and sore throat;

⁶(3-day) Fatigue, anosmia/ageusia, persistent cough, dyspnoea, diarrhoea, headache, (7-day) fatigue, fever, anosmia/ageusia, persistent cough;

⁷(3-day) Fatigue, fever, anosmia/ageusia, (7-day) Anosmia/ageusia, persistent cough, dyspnoea, diarrhoea, skipped meals, myalgia

TPC = Tests per case