Predictors of Influenza Diagnosis Among Patients With Laboratory-Confirmed Influenza.
OBJECTIVE
This study was performed to determine predictors of clinical influenza diagnosis among patients with laboratory-confirmed influenza.


METHODS
Prospective, laboratory-confirmed surveillance for influenza was conducted among patients of all ages who were hospitalized or presented to the emergency department with fever and respiratory symptoms during 2009-2013. We evaluated all enrolled persons who had influenza confirmed by viral culture and/or polymerase chain reaction and received any discharge diagnosis. The primary outcome, clinical influenza diagnosis, was defined as (1) a discharge diagnosis of influenza, (2) a prescription of neuraminidase inhibitor, or (3) a rapid test positive for influenza virus. Bivariate analyses and multiple logistic regression modeling were performed.


RESULTS
Influenza was diagnosed for 29% of 504 enrolled patients with laboratory-confirmed influenza and for 56% of 236 patients with high-risk conditions. Overall, clinical influenza diagnosis was predicted by race/ethnicity, insurance status, year, being hospitalized, having high-risk conditions, and receiving no diagnosis of bacterial infection. Being diagnosed with a bacterial infection reduced the odds of receiving an influenza diagnosis by >3-fold for all patients and for patients with high-risk conditions.


CONCLUSIONS
Many influenza virus-positive patients, including those with high-risk conditions, do not receive a clinical diagnosis of influenza. The pattern of clinical diagnoses among influenza virus-positive patients suggests preferential consideration of bacterial diseases as a diagnosis.
Department of Pediatrics.
Marc R
MR
Miller
Department of Pediatrics.
Timothy R
TR
Peters
Department of Biostatistical Sciences.
Cynthia K
CK
Suerken
Department of Biostatistical Sciences.
Beverly M
BM
Snively
Department of Pediatrics Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, North Carolina.
Katherine A
KA
Poehling
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015510:Clinical Medicine / Q000379:methods*; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007251:Influenza, Human / Q000175:diagnosis* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010818:Practice Patterns, Physicians'; D011446:Prospective Studies; D055815:Young Adult
antiviral agents; clinical practice patterns; diagnosis; human; influenza