Relationship Between Medical Questionnaire and Influenza Rapid Test Positivity: Subjective Pretest Probability, “I Think I Have Influenza,” Contributes to the Positivity Rate

Abstract

IntroductionRapid influenza diagnostic tests (RIDTs) are considered essential for determining when to start influenza treatment using anti-influenza drugs, but their accuracy is about 70%. Under the COVID-19 pandemic, we hope to refrain from performing unnecessary RIDTs considering droplet infection of COVID-19 and influenza. We re-examined the medical questionnaire's importance and its relationship to the positivity of RIDTs. Then we built a positivity prediction model for RIDTs using automated artificial intelligence (AI). MethodsWe retrospectively investigated 96 patients who underwent RIDTs at the outpatient department from December 2019 to March 2020. We used a questionnaire sheet with 24 items before conducting RIDTs. The factors associated with the positivity of RIDTs were statistically analyzed. We then used an automated AI framework to produce the positivity prediction model using the 24 items, sex, and age, with five-fold crossvalidation. ResultsOf the 47 women and 49 men (median age was 39 years), 56 patients were RIDT positive with influenza A. The AI-based model using 26 variables had an area under the curve (AUC) of 0.980. The stronger variables are subjective pretest probability, which is a numerically described score ranging from 0% to 100% of "I think I have influenza," cough, past hours after the onset, muscle pain, and maximum body temperature in order. ConclusionWe easily built the RIDT positivity prediction model using automated AI. Its AUC was satisfactory, and it suggested the importance of a detailed medical interview. Both the univariate analysis and AI-based model suggested that subjective pretest probability, "I think I have influenza," might be useful.

Importance of History Taking and Physical Examination Before Rapid Laboratory Test for Seasonal Influenza Virus: A Single-Center Multiple Logistic Analysis

“…The current study found that combining interviews and physical examination was important for predicting influenza test results [12]. While similar studies have been available to date, they have focused solely on symptoms, with only a few studies having analyzed a combination of interviews and physical examination [12,13].…”

“…In particular, interviews and physical examinations may preclude the need for invasive RIDTs among infants and reduce medical expenses [12]. Our study revealed that careful interviews and examination can predict RIDT results, highlighting their importance in clinical practice.…”

“…Second, facilities that perform drive-through tests sometimes only emerge after the flu becomes more prevalent [14]. Considering that Japan has a universal health insurance system, every citizen has easy access to medical examinations [10,12,15,16]. As such, clinics become saturated during the flu season [12].…”

“…Considering that Japan has a universal health insurance system, every citizen has easy access to medical examinations [10,12,15,16]. As such, clinics become saturated during the flu season [12]. There is a need to determine methods for predicting those who would test positive for the flu before RIDTs [10,12].…”

“…As such, clinics become saturated during the flu season [12]. There is a need to determine methods for predicting those who would test positive for the flu before RIDTs [10,12]. Of the patients enrolled in this study, 65.2% had undergone RIDTs within half a day of fever and 86.2% within one day.…”