Factors influencing sensitivity of a rapid influenza diagnostic test in
a community-based population of kindergarten through 12th grade
students: Wisconsin 2015-2020
Abstract
Rapid influenza diagnostic tests (RIDTs) have variable sensitivity. In a
community-based population of kindergarten through 12th grade (K-12)
students, we assessed factors that may influence RIDT performance using
2,368 paired results from Sofia® Influenza A + B fluorescent immunoassay
and reverse transcription polymerase chain reaction (RT-PCR). RIDT
sensitivity and specificity were 76.1% (95% CI: 72.8—79.1) and
97.2% (96.2—97.9), respectively. Factors associated with sensitivity
included runny nose (OR=3.0, p<0.001), nasal congestion (1.59,
p=0.045), days from symptom onset (per day; 0.75; p<0.001),
myalgia (0.61; p=0.014), age (per 5 years; 0.55; p=0.001), and detection
of another virus (0.50; p=0.043). Understanding these factors can aid in
interpreting negative results.