Table 1

- Subgroup analysis of ethnicity, saliva collection method, and participants’ symptoms.

Subgroup	Study (n)	DOR	Sensitivity	Specificity	AUC	NPV	PPV
95% CIs
I²
Self-collected saliva (total)	41	196.2022	0.8476	0.9817	0.955	0.9467	0.9404
		[117.8833-326.5546]	[0.8045-0.8826]	[0.9707-0.9887]		[0.9130-0.9678]	[0.9122-0.9599]
		82%	87.3%	89%		96.4%	83.2%
Regions
North America	20	250.4321	0.8798	0.9807		0.9635	0.9275
		[120.4677-520.6066]	[0.8182-0.9224]	[0.9646-0.9896]		[0.9265-0.9822]	[0.8801-0.9571]
		81.1%	84.5%	87.2%		94.1%	81.1%
Asia	12	92.3075	0.7938	0.9766		0.9283	0.9175
		[35.8172-237.8934]	[0.6970-0.8656]	[0.9297-0.9924]		[0.8056-0.9759]	[0.8410-0.9589]
		85.6%	87.1%	94.7%		0.9283 [0.8056-0.9759]	0.9175 [0.8410-0.9589]
Europe	6	212.1821	0.8080	0.9852		0.9143	0.9676
		[117.6169-382.7785]	[0.6984-0.8844]	[0.9751-0.9912]		[0.7872-0.9685]	[0.9369-0.9836]
		0%	82.4%	0%		95%	30.9%
South America	2	748.1044	0.8814	0.9924		0.9189	0.9839
		[171.1188-3270.5945]	[0.7180-0.9559]	[0.9321-0.9992]		[0.8642-0.9527]	[0.9378-0.9960]
		0%	71.2%	35.1%		5.2%	0%
Oceania	1	269.5000	0.8462	0.9800		0.8909	0.9706
		[31.0018-2342.7756]	[0.6974-0.9292]	[0.8712-0.9972]		[0.7777-0.9502]	[0.8186-0.9959]
		NA	NA	NA		NA	NA
P-value		0.1979	0.389	0.8652		0.2833	0.079
Collection method
Only oral cavity saliva	26	215.1566	0.8365	0.9827		0.9496	0.9367
		[110.2014-420.0706]	[0.7793-0.8812]	[0.9713-0.9896]		[0.9111-0.9719]	[0.9007-0.9602]
		84%	87.4%	84.4%		96.1%	80.9%
Only oral cavity saliva (not defined)	8	237.4246	0.8919	0.9820		0.9731	0.9173
		[61.4927-916.7010]	[0.8432-0.9268]	[0.9035-0.9969]		[0.9269-0.9904]	[0.7993-0.9686]
		85.2%	28.7%	96.3%		89.7%	86.0%
Enhanced saliva	7	127.2254	0.8353	0.9779		0.8823	0.9654
		[41.0992-393.8348]	[0.6844-0.9222]	[0.9338-0.9928]		[0.6404-0.9693]	[0.9075-0.9875]
		67.0%	91.7%	75.7%		2.0842	70.9%
P-value		0.7001	0.2282	0.928		0.2176	0.4355
Patient symptom
Symptomatic	22	245.6222	0.8851	0.9791		0.9522	0.9495
		[111.2860-542.1192]	[0.8497-0.9130]	[0.9580-0.9898]		[0.9124-0.9744]	[0.9103-0.9721]
		80.6%	71.0%	87.3%		92.2%	80.3%
Mixed	15	159.4638	0.8208	0.9783		0.9164	0.9435
		[72.7019-349.7664]	[0.7399-0.8806]	[0.9588-0.9886]		[0.8313-0.9606]	[0.9003-0.9687]
		83.4%	90.7%	85.6%		97.0%	82.4%
Asymptomatic	4	184.8991	0.7049	0.9933		0.9772	0.8483
		[44.5856-766.7872]	[0.4705-0.8653]	[0.9673-0.9987]		[0.8563-0.9968]	[0.6869-0.9345]
		80.3%	82.3%	92.3%		97.0%	71.2%
P-value		0.7469	0.03	0.3924		0.329	0.0879

DOR: diagnostic odds ratio, CI: confidence interval, AUC: area under the curve, NPV: negative predictive value, PPV: positive predictive value