Use of simple heuristics to target macrolide prescription in children with community-acquired pneumonia.
BACKGROUND
Macrolides are the first-line antibiotic treatment of community-acquired pneumonia (CAP). Owing to alarming resistance rates among invasive Streptococcus pneumoniae isolates, particularly in young children, macrolide use should be restricted to patients infected with susceptible pathogens, eg, Mycoplasma pneumoniae.


OBJECTIVE
To develop a simple clinical prediction rule for identifying M pneumoniae as the cause of CAP in children.


METHODS
Prospective cohort study in 253 children with radiologically confirmed CAP in a walk-in clinic of a tertiary care hospital.


METHODS
Mycoplasma infection, proven by results of antibody testing of paired serum samples (gold standard). We compared the area under the receiver operating characteristic curve (c statistic) of the following 2 prediction models: a scoring system derived from logistic regression analysis and a fast-and-frugal decision tree.


RESULTS
Mycoplasma pneumoniae infection was confirmed in 32 (13%) of 253 children. A scoring system based on duration of fever and patient age yielded a c statistic of 0.84 (95% confidence interval [CI], 0.77-0.91), compared with that of the decision tree (c = 0.76 [95% CI, 0.70-0.83]). The scoring system identified 75% of all cases as being at high or very high risk for M pneumoniae infection; the decision tree, 72% at high risk. The scoring system would curtail macrolide prescriptions by 75%; the decision tree, by 68%.


CONCLUSIONS
In children with CAP, simple clinical decision rules identify patients at risk for M pneumoniae infection. At present US macrolide resistance rates among invasive S pneumoniae isolates, both rules increase the chance of prescribing effective first-line antibiotics compared with general macrolide administration.
D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D002648:Child; D017714:Community-Acquired Infections / Q000188:drug therapy* / Q000382:microbiology*; D003661:Decision Support Techniques; D003663:Decision Trees; D006801:Humans; D016015:Logistic Models; D018942:Macrolides; D011014:Pneumonia / Q000188:drug therapy* / Q000382:microbiology*; D011019:Pneumonia, Mycoplasma / Q000175:diagnosis / Q000188:drug therapy; D011446:Prospective Studies; D012372:ROC Curve
D000900:Anti-Bacterial Agents; D018942:Macrolides