[Cost-effectiveness of diagnostic strategies of severe bacterial infection in infants with fever without a source].

INTRODUCTION: Serious bacterial infections in infants under 2-years-of-age with fever without a source remains, despite advances in vaccination, a matter of concern for both physicians and parents. Having cost-effectiveness information is relevant to guide decision making in clinical practice in this scenario. Objective: To determine the cost-effectiveness of four different strategies of screening in Argentina for serious bacterial infection in children presenting with fever without a source. Materials and methods: We designed a decision tree to model a hypothetical cohort of 10,000 children with fever without a source. We compared the incremental cost-effectiveness of four strategies to detect serious bacterial infection: Rochester criteria + C reactive protein test, Rochester criteria + procalcitonin test, Rochester criteria, and expectant observation. Results: Rochester criteria + C reactive protein test was the most cost-effective strategy with USD$ 784 for each correctly diagnosed case versus USD$ 839 of Rochester criteria + procalcitonin test, USD$ 1,116 of expectant observation or USD$ 1,193 of Rochester criteria. When the probability of serious bacterial infections was equal or less than 14%, the strategy of choice was expectant observation. Conclusions: The Rochester criteria + C reactive protein test was the most cost-effective strategy to detect serious bacterial infection in one to three months old children with fever without a source. However, in low risk settings for such infection, the strategy of choice is expectant observation.