Individual maternal and child exposure to antibiotics in hospital : a national population-based validation study

Aim: Exposure to antibiotics in early life may affect future health. Most antibiotics are prescribed in outpatient care, but inpatient exposure is also important. We estimated how specific diagnoses in hospitals corresponded to individual antibiotic exposure. Methods: All pregnant women and children from birth to five-years-of-age with infectious diseases and common inpatient diagnoses between July 2005 and November 2011were identified from the Swedish National Patient Register. Random samples of individuals from pre-defined groups were drawn and medical records received from the clinics were manually reviewed for antibiotics. Results: Medical records for 4,319 hospital visits were requested and 3,797 (88%) were received. A quarter (25%) of children diagnosed as premature had received antibiotics and in children from one to five-years-of-age, diagnoses associated with bacterial infections were more commonly treated with antibiotics (62.4-90.6%) than those associated with viruses (6.3-22.2%). Pregnant women who had undergone a Caesarean section were more likely to be treated with antibiotics than those who had had a vaginal delivery (40.1% versus 11.1%). Conclusions: This study defines the proportion of new mothers and young children who received individual antibiotic treatment for specific inpatient diagnoses in Sweden and provides a useful basis for future studies focusing on antibiotic use.Swedish Research Council, 2011-3060Swedish Initiative for Research on Microdata in the Social And Medical Sciences (SIMSAM), 80748301 and 340-2013- 5867Stockholm County Council (ALF)Swedish Heart Lung FoundationStrategic Research Program in Epidemiology at Karolinska InstitutetManuscrip

Study population and medical record request for pregnant women.

<p>Medical records were randomly selected from a register-based cohort of patients treated in Swedish hospitals between July 2005 and November 2011. Abbreviations: NPR = National Patient Register, MBR = Medical Birth Register, SPDR = Swedish Prescribed Drug Register, ICD-10 = International Classification of Disease 10^th revision.</p

Study population and medical record request for infants 0–12 months.

<p>Medical records were randomly selected from a register-based cohort of patients treated in Swedish hospitals between July 2005 and November 2011. Abbreviations: NPR = National Patient Register, SPDR = Swedish Prescribed Drug Register, ICD-10 = International Classification of Disease 10^th revision.</p

Boxplot with mean (◆) for length of stay for women by delivery mode.

<p>For elective CS, the median is equal to the lower quartile. Abbreviations: CS = Caesarean section</p

Risk ratios (RR) and 95% confidence intervals (CI) for antibiotic treatment by prematurity, sex and age in infants 0–12 months of age.

<p>Risk ratios (RR) and 95% confidence intervals (CI) for antibiotic treatment by prematurity, sex and age in infants 0–12 months of age.</p

Risk ratios (RR) and 95% confidence intervals (CI) for antibiotic treatment in relation to delivery mode and maternal age at delivery (N = 203).

<p>Risk ratios (RR) and 95% confidence intervals (CI) for antibiotic treatment in relation to delivery mode and maternal age at delivery (N = 203).</p

Antibiotic Treatment and Length of Hospital Stay in Relation to Delivery Mode and Prematurity.

To investigate how 1) maternal delivery mode and 2) prematurity in infants are associated to antibiotic treatment and length of hospital stay.Women having given birth and infants 0-12 months discharged from hospital between July 2005 and November 2011 were identified from the Swedish National Patient Register. Medical records were reviewed for 203 women and 527 infants. The risk ratio (RR) between antibiotic treatment and 1) delivery mode in women; 2) prematurity in infants was calculated. Length of stay and days of antibiotic therapy were compared by Wilcoxon rank-sum test.Women: There was an association between emergency caesarean section (CS) and antibiotic treatment (RR 5.0 95% confidence interval (CI) 2.2-11.5), but not for elective CS. Length of stay was longer for CS (emergency and elective) compared to vaginal delivery (p<0.01). Infants: RR for antibiotic treatment in preterm compared to term infants was 1.4 (95% CI 1.0-1.9). Length of stay (p<0.01), but not days of therapy (p = 0.17), was higher in preterm compared to term infants.We found that emergency CS increased the probability of maternal antibiotic treatment during hospitalisation, but no difference was found between term and preterm infants. The results are well aligned with current guidelines and may be considered in future studies on the effects of antibiotics