To determine the clinical utility and cost-effectiveness of universal vs targeted approach to obtaining blood cultures in children hospitalized with community-acquired pneumonia (CAP).

We conducted a cost-effectiveness analysis using a decision tree to compare 2 approaches to ordering blood cultures in children hospitalized with CAP: obtaining blood cultures in all children admitted with CAP (universal approach) and obtaining blood cultures in patients identified as high risk for bacteremia (targeted approach). We searched the literature to determine expected proportions of high-risk patients, positive culture rates, and predicted bacteria and susceptibility patterns. Our primary clinical outcome was projected rate of missed bacteremia with associated treatment failure in the targeted approach. Costs per 100 patients and annualized costs on the national level were calculated for each approach.

The model predicts that in the targeted approach, there will be 0.07 cases of missed bacteremia with treatment failure per 100 patients, or 133 annually. In the universal approach, 118 blood cultures would need to be drawn to identify 1 patient with bacteremia, in which the result would lead to a meaningful antibiotic change compared with 42 cultures in the targeted approach. The universal approach would cost $5178 per 100 patients or $9 214 238 annually. The targeted approach would cost $1992 per 100 patients or $3 545 460 annually. The laboratory-related cost savings attributed to the targeted approach would be projected to be $5 668 778 annually.

This decision analysis model suggests that a targeted approach to obtaining blood cultures in children hospitalized with CAP may be clinically effective, cost-saving, and reduce unnecessary testing.