BACKGROUND: The factors and patterns associated with antibiotic consumption in infants are unclear. Our aim was to assess the cumulative incidence of antibiotic consumption from birth to 16 months and identify factors associated with antibiotic consumption among infants aged 4-16 months.
METHODS: We conducted a cross-sectional study in 2016 in a sample of 18 882 women from Galicia, Spain, who had given birth to a live child between September 1, 2015 and August 31, 2016. We calculated the cumulative incidence of antibiotic consumption based on maternal reports regarding the infant\'s consumption from birth to 14 months obtained through interviews; we did not estimate consumption at ages 15 and 16 months due to the small sample size. To assess which factors were associated with antibiotic consumption, we carried out a nested case-control study matching cases and controls for birth month on a 1:1 ratio.
RESULTS: The cumulative incidence of antibiotic consumption among infants aged 0-14 months increased from 7.5% to 66.0%. The case-control study included data for 1852 cases and 1852 controls. Daycare attendance (OR: 3.8 [95% CI: 3.2-4.6]), having older siblings (OR: 1.8 [95% CI: 1.6-2.1]), health care visits to private clinics (OR: 1.6 [95% CI: 1.4-2.0]), and passive smoking (OR: 1.3 [95% CI: 1.1-1.6]) were associated with an increased probability of antibiotic consumption. Maternal age between 30-39 years or 40 years and over at the time of birth was associated with a decreased probability of antibiotic consumption (OR: 0.8 [95% CI, 0.7-1.0] and OR: 0.6 [95% CI: 0.5-0.8], respectively).
CONCLUSIONS: Some of the factors associated with antibiotic consumption in infants are modifiable and should be considered in the development of public health measures aimed at reducing antibiotic consumption.

BACKGROUND: Antimicrobial defined daily dose (DDD), has limitations for antimicrobial consumption measurement in paediatrics. An alternative DDD design applicable for children is proposed.
METHODS: Children (<16 years-old) from 10 Spanish hospitals during a 12-months period were included. Weight for age (50th percentile) was calculated for the median age of the cohort using standardized World Health Organization tables. DDD (g) for each antimicrobial was calculated by multiplying the obtained weight times the recommended dose (mg/kg) of the antimicrobial for the most common infectious indication.
RESULTS: A total of 40,575 children were included. Median age was 4.17 (IQR: 1.36-8.98) and 4.81 (IQR: 1.42-9.60) years for boys and girls, respectively. Mean weight for this age was 17.08kg. Standardized DDD for representative antimicrobials were calculated.
CONCLUSIONS: A useful method for antimicrobial DDD measurement in paediatrics has been proposed and should be validated in future studies for its use in paediatric antimicrobial stewardship programmes.

BACKGROUND: Information about paediatric in-hospital antimicrobial usage and prescribing patterns to guide improvement strategies is scant. We aim to use an evaluation of the prevalence and appropriateness of antimicrobial prescription to identify antimicrobial stewardship priorities in children.
METHODS: A cross-sectional point study was performed on hospitalised paediatric patients in a Spanish tertiary hospital, assessing the prevalence of antimicrobial prescription (PAP) and appropriateness of antimicrobial prescription (AAP). AAP was defined as a correct indication plus an appropriate prescribing pattern (dose, spectrum and interval). Evaluation was performed using established antimicrobial guidelines. Other factors that may have a bearing on antimicrobial prescription were also analysed.
RESULTS: A total of 171 patients were included. PAP was 49.7% (85/171) and AAP was 60.9% (91/161). The most common indications for antimicrobial use were antimicrobial prophylaxis (28.3%, 32/113) and pneumonia (8.2%, 8/113). Overall, 161 antimicrobials were prescribed (1.9 antimicrobials per patient): 55.3% (89/161) were empiric, 16.1% (26/161) were targeted and 28.6% (46/161) were prophylactic. Amoxicillin/clavulanate (8.2%, 14/171) and sulfamethoxazole/trimethoprim (8.2%, 14/171) were the most prescribed antimicrobials. The prescription of antifungals (11.7%, 20/171) and antivirals (1.8%, 3/171) was analysed. Major causes of inappropriate antibiotic use were prolonged prescriptions (21.7%, 35/161) and use of agents with an excessively broad coverage spectrum (21.1%, 34/161). PAP and AAP varied between wards and antimicrobials.
CONCLUSIONS: Measurement of PAP and AAP offers valuable information for detecting priorities in hospital settings and monitoring antimicrobial usage prior to the development of antimicrobial stewardship programmes. In our setting, the main areas for improvement are duration of therapy and proper use of broad-spectrum antimicrobials.

Evaluating the impact of antibiotic stewardship programs is challenging. There is evidence that they are effective in terms of reducing the consumption and cost of antibiotics, although establishing their impact on antimicrobial resistance (beyond restrictive policies in outbreaks caused by specific antimicrobial resistant organisms) and clinical outcomes is more difficult. Proper definitions of exposure and outcome variables, the use of advanced and appropriate statistical analyses and well-designed quasi-experimental studies would more accurately support the conclusions. Cluster randomized trials should be used whenever possible and appropriate, although the limitations of this approach should also be acknowledged. These issues are reviewed in this paper. We conclude that there are good research opportunities in the field of antibiotic stewardship.

In Spain, the inclusion of new antibiotics in hospital formularies is performed by the Infection Policy Committee or the Pharmacy and Therapeutic Committee, although now the decision is moving to a regional level. Criteria for the evaluation of new drugs include efficacy, safety and cost. For antimicrobial drugs evaluation it is necessary to consider local sensibility and impact in bacterial resistance to determinate the therapeutic positioning. There is compelling evidence that the use of antibiotics is associated with increasing bacterial resistance, and a great number of antibiotics are used incorrectly. In order to decrease the inappropriate use of antibiotics, several approaches have been proposed. Limiting the use of antimicrobials through formulary restrictions, often aimed at drugs with a specific resistance profile, shows benefits in improving antimicrobial susceptibilities and decreasing colonization by drug-resistant organisms. However, the restriction of one agent may result in the increased utilization of other agents. By using antibiotic cycling, the amount of antibiotics is maintained below the threshold where bacterial resistance develops, thus preserving highly efficient antibiotics. Unfortunately, cumulative evidence to date suggests that antibiotic cycling has limited efficacy in preventing antibiotic resistance. Finally, although there is still little clinical evidence available on antibiotic heterogeneity, the use of most of the existing antimicrobial classes could limit the emergence of resistance. This review summarizes information regarding antibiotic evaluation and available restrictive strategies to limit the use of antibiotics at hospitals with the aim of curtailing increasing antibiotic resistance.