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Peer reviewedOpen accessSARSCOVID-19

Diagnostic performance of different sampling approaches for SARS-CoV-2 RT-PCR testing: a systematic review and meta-analysis

The Lancet Infectious Diseases·

Nicole Ngai Yung Tsang, Hau Chi So, Ka Yan Ng, Benjamin J Cowling, Gabriel M Leung, Dennis Kai Ming Ip

DOI
10.1016/s1473-3099(21)00146-8
PMID
33857405
PMCID
PMC8041361
OpenAlex
W3153427680
Study type
Systematic review
Publisher
Elsevier BV
Article type
journal-article
Integrity
current

Why this research matters now

The findings suggest pooled nasal and throat swabs, and to a slightly lesser extent saliva and nasal swabs, are clinically acceptable alternatives to nasopharyngeal swabs for SARS-CoV-2 RT-PCR testing in ambulatory settings, while throat swabs alone appear insufficient.

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Structured evidence summary

Research question

This review examined how different respiratory specimen collection methods compare with nasopharyngeal swabs for diagnosing SARS-CoV-2 infection by RT-PCR in ambulatory care populations with suspected infection.

Study design

A systematic review and meta-analysis searching eight databases from January 2000 through November 16, 2020, using random-effects models with double arcsine transformation to estimate diagnostic performance metrics.

Population and setting

Ambulatory care individuals with suspected SARS-CoV-2 infection; the pooled analysis included 23 studies, 7,973 participants, and 16,762 respiratory samples.

Main findings

Using nasopharyngeal swabs as the reference, pooled nasal and throat swabs showed the highest sensitivity at 97% (95% CI 93–100). Saliva and nasal swabs had somewhat lower sensitivities (85% and 86%, respectively), while throat swabs performed substantially worse at 68%. Positive predictive values were highest for pooled nasal and throat swabs (97%) and nasal swabs (96%), with throat swabs lowest at 75%. Specificities and negative predictive values were similarly high across specimens. Self-collection performed comparably to health-care-worker collection for pooled nasal and throat swabs and nasal swabs.

Public-health relevance

The findings suggest pooled nasal and throat swabs, and to a slightly lesser extent saliva and nasal swabs, are clinically acceptable alternatives to nasopharyngeal swabs for SARS-CoV-2 RT-PCR testing in ambulatory settings, while throat swabs alone appear insufficient.

Important limitations

The review reported no significant heterogeneity for pooled nasal and throat swabs and throat swabs, but moderate to substantial heterogeneity (I² ≥30%) for saliva and nasal swabs, and included only studies with paired-sample data from ambulatory populations. This summary is limited to the supplied single-article abstract/metadata and requires the original paper for decision-grade interpretation.

GIDS interpretation

This article is discoverable through diagnostic and outbreak-investigation classifiers and is relevant to surveillance contexts evaluating SARS-CoV-2 specimen collection; the abstract alone does not confirm any live surveillance signal.

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Related GIDS surveillance

Literature context does not validate, explain, or change a surveillance signal. Exact and contextual relationships are shown separately.

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Evidence relationships

This article has 9 auditable classifier relationships to diseases, places, topics, and study design.

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