The Research Question Performance of a Rapid Influenza Detection Test (RIDT) in Ambulatory Primary Care Wisconsin: 2009-2013 Temte JL, Barlow S, Greene P, Haupt T, Reisdorf E, Wedig M, Shult P, Giorgi A, Fowlkes A. University of Wisconsin What patient, illness and pathogen characteristics affect performance of rapid influenza detection tests? Why this is important? RIDTs are designed to provide point-of-care diagnosis of influenza to inform treatment and guidance decisions in a meaningful timeframe RIDTs have been limited by some performance measures – primarily sensitivity Package inserts suggest that age can affect sensitivity BP34 Adherence to Antibiotic Prescribing for LRTI and Association With Recovery (Oral Presentation On Completed Research) Nick Francis, MD, PhD, Cardiff University; David Gillespie; Jacqueline Nuttall; Paul Little; Theo Verheij; Samuel Coenen; Jochen Cals; Kerenza Hood; Herman Goossens; Christopher Butler

What the Researchers Did Population/Subjects Primary care patients with acute respiratory infections N = 1,219 (age 0 to 88.1 years) November 2009 to April 2013 Four family medicine clinics in Wisconsin Design: Prospective respiratory virus surveillance Pragmatic (multiple sites, 90 clinicians, diverse ARIs) Basic Method/Intervention Comparison of sensitivity of RIDT to gold standard PCR RIDT: Quidel QuickVue Influenza A+B CDC influenza RT-PCR primers and Qiagen Resplex II Multiplex PCR Uniform demographic, epidemiologic and symptom data on all patients aged ≥18 years, consulting with an illness where an acute or worsened cough was the main or dominant symptom, or had a clinical presentation that suggested a lower respiratory tract infection that had been present for ≥28 days.

What the Researchers Found Factors associated with Sensitivity univariate analysis (Chi Square) Sex of Patient N.S Male > Female Age of patient P=0.001 younger > older (7 age groups) ILI vs. ARI N.S. ILI > ARI Days from onset P=0.001 earlier > later (5 time groups Vaccinated N.S. Unvaccinated > vaccinated Influenza strain N.S. B > AH3 > AH1 mulitvariate analysis (Binary Logistic Regression) Age of patient Sensitivity drops by 20% for each decade of life Odds ratio = 0.80 P = 0.004 Days from Onset Sensitivity drops by 26% for each passing day after onset Odds ratio = 0.74 P = 0.01

What This Means for Clinical Practice Rapid Influenza Diagnostic Test performance is complex and requires appropriate patient selection Patient Age and Time from Illness Onset are key parameters Sensitivity drops by 20% for each decade of life Sensitivity drops by 26% for each passing day after illness onset The messiness and chaos allowed by a Primary Care Surveillance Platform offers an excellent means to evaluate the effectiveness of diagnostic technology