Skip directly to search Skip directly to A to Z list Skip directly to page options Skip directly to site content

Volume 16, Number 5—May 2010

Dispatch

Rapid Influenza Antigen Test for Diagnosis of Pandemic (H1N1) 2009

Janice K. LouieComments to Author , Hugo Guevara, Erica Boston, Melissa Dahlke, Maria Nevarez, Tong Kong, Robert Schechter, Carol A. Glaser, and David P. Schnurr
Author affiliations: California Department of Public Health, Richmond, California, USA

Main Article

Table

Performance of rapid antigen test compared with PCR in the diagnosis of pandemic (H1N1) 2009*

Parameter All specimens Patient age <18 y† Patient age >18 y†
No. rapid test positive, PCR positive 266 131 130
No. rapid test positive, PCR negative 49 19 28
No. rapid test negative, PCR positive 138 62 74
No. rapid test negative, PCR negative 250 78 166
Total no. tested
703
290
398
Prevalence of PCR positives in sample 0.57 0.67 0.51
Sensitivity 0.66 0.68 0.64
Specificity 0.84 0.80 0.86
Positive predictive value 0.84 0.87 0.82
Negative predictive value
0.64
0.56
0.69
Positive likelihood ratio (95% CI) 4.0 (3.1–5.2) 3.5 (2.3–5.3) 4.4 (3.1–6.3)
Posterior probability of positive test result (95% CI) 0.84 (0.81–0.88) 0.87 (0.82–0.91) 0.82 (0.76–0.87)
Negative likelihood ratio (95% CI) 0.41 (0.35–0.47) 0.40 (0.32–0.50) 0.42 (0.35–0.51)
Posterior probability of negative test result (95% CI) 0.36 (0.32–0.39) 0.44 (0.39–0.50) 0.31 (0.27–0.35)

*CI, confidence interval.
†Does not include results for 15 case-patients where age was not recorded.

Main Article

TOP