Validated clinical decision rule to guide management for patients with suspected influenza
Is there an accurate clinical decision rule for guiding point-of-care testing and empiric therapy for adults with suspected influenza?
An accurate clinical decision rule based on 2 points for fever plus cough, 2 points for myalgia, 1 point for symptom duration of less than 48 hours, and 1 point for chills or sweats, can be used to guide point-of-care management of adults with suspected influenza. (LOE = 2b)
Ebell MH, Afonso AM, Gonzales R, Stein J, Genton B, Senn N. Development and validation of a clinical decision rule for the diagnosis of influenza. J Am Board Fam Med 2012(1);25:55-62. [PubMed ® abstract | Free full-text JABFM article PDF]
Study design: Decision rule (validation)
Funding Source: Self-funded or unfunded
These investigators identified 2 prospective cohort studies reporting the accuracy of clinical signs and symptoms of influenza for adults in the outpatient setting. In both studies, either the polymerase chain reaction assay or culture appropriately served as the reference standard. The dataset was randomly divided to provide a derivation group (70%; n = 326) and validation group (30%; n = 133). Stepwise logistic regression was performed using the derivation group to create 3 potential predictive models. These 3 models, and 2 additional already-published multivariate models, were evaluated using the validation subgroup. Cut points for risk-group stratification into low-, moderate- and high-risk were determined for each model. The most useful and accurate clinical rule that performed similarly in both the derivation and validation groups was the following: 2 points for fever plus cough, 2 points for myalgia, 1 point for symptom duration of less than 48 hours, and 1 point for chills or sweats. The risk for influenza using this rule was 8% for 0 to 2 points, 30% for 3 points, and 59% for 4 to 6 points. The authors speculate that during a peak influenza season clinicians should consider empiric therapy for patients at high risk; point-of-care rapid testing for those at moderate risk; and observation only for those at low risk.
David Slawson, MD
Vice Chair, Department of Family Medicine
University of Virginia
Copyright © 2012 John Wiley & Sons