This population-based study of 8-month-old children in the city of Malmö, Sweden, showed that the use of antibiotics up to this young age was increased among children whose parents were born outside of Sweden, had a low educational level, experienced economic stress, or had low emotional support. Although exposure to environmental smoking was associated with an increased antibiotic use in the crude model, this association was attenuated and turned non-significant after adjustment for potential confounders. Breastfeeding seemed to have a protective role against antibiotic treatment. Furthermore, the odds of antibiotic use were significantly increased by being a boy, having a low birth weight, having siblings, and having an allergy.
In our study, antibiotic consumption was significantly higher among children whose parents were less well educated. Similar results have been shown in other studies [8, 10]. The reasons for this result might include an increased exposure to infectious agents due to crowding, poor nutrition, smoking, and stress . However, there are also studies that have shown a lower use of antibiotics in families where the parents had a low educational level . Use of antibiotics was also higher in families where both parents were born outside of Sweden, a finding supported by another study performed in the USA . This could be partly due to different cultural traditions in relation to having a disease. Earlier studies, including a study from Malmö, Sweden, among 4-year old children, have shown an association between exposure to environmental smoking and increased antibiotic use [6, 11]. We found a similar pattern of association in the crude model of our study, but the association turned non-significant after adjustment for potential confounders. Earlier studies have shown a higher antibiotic consumption among the children of families experiencing stress and parents in need of support from outside the family [10, 12]. Our study showed similar results, with higher antibiotic use among parents with low emotional support as well as among parents experiencing economic stress. As in other studies [10, 12], boys were prescribed antibiotics more frequently. Furthermore, children who were not breastfed at all had increased odds of using antibiotics. This finding of a protective role from breastfeeding is supported by other studies [11, 15].
Certain methodological issues need to be addressed. All parents with 8-month-old children were invited to participate in the study by answering the questionnaire. The total number of children whose parents answered the questionnaire during the four-year study period was 7266, or about two thirds of all those who received the questionnaire. We have no information about the country of birth in the non-participating families, but according to Rosvall et al. , the non-participants had a somewhat higher proportion of parents born outside of Sweden. This might have resulted in an underestimation of the total prevalence of antibiotic consumption, since our results indicate that there was a higher antibiotic consumption among children with both parents born outside of Sweden. There were no educational differences between the participants and non-participants . One strength of this study was the fact that the questionnaire had been validated and tested for reliability and translated into five different languages . According to the Malmö city website, these languages are among the most common languages represented in Malmö . However, there may still have been some bias, as despite the multiple translations some parents may have had difficulties in understanding the questions. Another problem with the questionnaire was that some questions may be more sensitive than others (smoking, economy, and emotional support), and some parents may not have been willing to answer them. We chose to adjust for the following confounding factors: male gender, parents' country of birth, parental educational level, and recurrent infections. Since there were differences in antibiotic consumption during the different years of the study, we also adjusted for the year. However, there might have been other confounding factors not included in our models.