Traditional flu tests not as accurate as newer tests

(HealthDay)—Digital immunoassays (DIAs) and rapid nucleic acid amplification tests (NAATs) have higher sensitivities for detecting influenza than rapid influenza diagnostic tests (RIDTs), according to a review published online Sept. 4 in the Annals of Internal Medicine.

Joanna Merckx, M.D., from McGill University in Canada, and colleagues compared the accuracy of traditional RIDTs, DIAs, and rapid NAATs in children and adults with suspected influenza. They extracted date from 162 studies (130 of RIDTs, 19 of DIAs, and 13 of NAATs).

The researchers found that the pooled sensitivities for detecting influenza A using Bayesian bivariate random-effects models were 54.4 percent for RIDTs, 80 percent for DIAs, and 91.6 percent for NAATs. For detecting influenza B, the pooled sensitivities were 53.2 percent for RIDTs, 76.8 percent for DIAs, and 95.4 percent for NAATs. Pooled specificities were consistently high (>98 percent). Based on 46 influenza A and 24 influenza B studies with pediatric-specific data and 35 influenza A and 16 influenza B studies with adult-specific data, pooled sensitivities were higher in children by 12.1 to 31.8 percentage points, with the exception of influenza A detected by rapid NAATs (2.7 percentage points). Industry-sponsored studies had higher pooled sensitivities by 6.2 to 34 percentage points.

"Novel DIAs and rapid NAATs had markedly higher sensitivities for influenza A and B in both children and adults than did traditional RIDTs, with equally high specificities," conclude the authors.

Several authors report financial ties to the diagnostics industry, including BD Diagnostic Systems, which provided funding for the study.