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sp Infect. 2017 May 27. pii: S0195-6701(17)30287-6. doi: 10.1016/j.jhin.2017.05.017. [Epub ahead of print] Clinical performance and economic evaluations of the Alere? i Influenza A&B near patient test using throat swabs: a cohort diagnostic accuracy study and cost analysis.
Davis S1, Allen J2, O'Leary R3, Power M3, Price D4, Simpson J2, Tunbridge A5, Vale L6, Whiteside M7, Evans C8, Raza M8.
Author information
Abstract
BACKGROUND:
Clinical diagnostic sensitivity alone is inadequate in the diagnosis of influenza. PCR testing is sensitive however the inherent delays in result availability potentially prolong time to isolation and treatment. Until recently no near patient test (NPT) has demonstrated adequate sensitivity for routine clinical use.
AIM:
To evaluate diagnostic accuracy; time to result availability; clinical impact and cost consequences of Alere? i Influenza A&B NPT (Alere Inc., Waltham, MA, USA) using off-label throat swabs.
METHODS:
Prospective, multi-centre (4 UK NHS hospitals), diagnostic accuracy cohort study with cost modelling. Throat swab samples from suspected influenza patients were tested for influenza using the reference standard of PCR; a second throat swab was tested using NPT.
FINDINGS:
827 participants recruited; 589 suitable for analysis: Sensitivity 75.8% (95% CI 67.0-84.6%); specificity 96.8% (95% CI 95.2-98.3%). Sensitivity varied between Sheffield (NGH 82.1%; RHH 83.3%) and other sites (DRI 71.4%; RVI 50.0%) while specificity was high (92% - 100%). PPV was 81.2% (95% CI 72.9- 89.5%) with NPV 95.6% (95% CI 93.9-97.4%) with observed prevalence of 15.4%. Median time to result for PCR was 1.1 days (on-site laboratories) and 5.2 days (remote laboratories). Isolation findings: 75% influenza positive not isolated; 69% isolated participants did not have influenza. For a cohort of 1000 participants, annual estimated non-diagnostic cost savings with NPT are ?215, 040.
CONCLUSIONS:
This first prospective study of the Alere? i NPT using throat swabs demonstrates high specificity, high PPV during seasonal epidemics, and rapid result availability which could lead to substantial cost savings.
Copyright ? 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
KEYWORDS:
Alere-i; Influenza; adults; cost analysis; infection control; point-of-care testing; respiratory viruses
PMID: 28558954 DOI: 10.1016/j.jhin.2017.05.017
Davis S1, Allen J2, O'Leary R3, Power M3, Price D4, Simpson J2, Tunbridge A5, Vale L6, Whiteside M7, Evans C8, Raza M8.
Author information
Abstract
BACKGROUND:
Clinical diagnostic sensitivity alone is inadequate in the diagnosis of influenza. PCR testing is sensitive however the inherent delays in result availability potentially prolong time to isolation and treatment. Until recently no near patient test (NPT) has demonstrated adequate sensitivity for routine clinical use.
AIM:
To evaluate diagnostic accuracy; time to result availability; clinical impact and cost consequences of Alere? i Influenza A&B NPT (Alere Inc., Waltham, MA, USA) using off-label throat swabs.
METHODS:
Prospective, multi-centre (4 UK NHS hospitals), diagnostic accuracy cohort study with cost modelling. Throat swab samples from suspected influenza patients were tested for influenza using the reference standard of PCR; a second throat swab was tested using NPT.
FINDINGS:
827 participants recruited; 589 suitable for analysis: Sensitivity 75.8% (95% CI 67.0-84.6%); specificity 96.8% (95% CI 95.2-98.3%). Sensitivity varied between Sheffield (NGH 82.1%; RHH 83.3%) and other sites (DRI 71.4%; RVI 50.0%) while specificity was high (92% - 100%). PPV was 81.2% (95% CI 72.9- 89.5%) with NPV 95.6% (95% CI 93.9-97.4%) with observed prevalence of 15.4%. Median time to result for PCR was 1.1 days (on-site laboratories) and 5.2 days (remote laboratories). Isolation findings: 75% influenza positive not isolated; 69% isolated participants did not have influenza. For a cohort of 1000 participants, annual estimated non-diagnostic cost savings with NPT are ?215, 040.
CONCLUSIONS:
This first prospective study of the Alere? i NPT using throat swabs demonstrates high specificity, high PPV during seasonal epidemics, and rapid result availability which could lead to substantial cost savings.
Copyright ? 2017 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
KEYWORDS:
Alere-i; Influenza; adults; cost analysis; infection control; point-of-care testing; respiratory viruses
PMID: 28558954 DOI: 10.1016/j.jhin.2017.05.017