Antibiotic prescription for outpatients with influenza and subsequent hospitalisation: A cohort study using insurance data.

Background: Whether prophylactic administration of antibiotics to patients with influenza reduces the hospitalisation risk is unknown. We aimed to examine the association between antibiotic prescription in outpatients with influenza infection and subsequent hospitalisation. Methods: We conducted a cohort study using health insurance records of Japanese clinic and hospital visits between 2012 and 2016. Participants were outpatients (age, 0-74 years) with confirmed influenza infection who were prescribed anti-influenza medicine. The primary outcomes were the hospitalisation risk from all causes and pneumonia and the duration of hospitalisation due to pneumonia. Results: We analysed 903,104 outpatient records with 2469 hospitalisations. The risk of hospitalisation was greater in outpatients prescribed anti-influenza medicine plus antibiotics (0.31% for all causes and 0.18% for pneumonia) than in those prescribed anti-influenza medicine only (0.27% and 0.17%, respectively). However, the risk of hospitalisation was significantly lower in patients prescribed peramivir and antibiotics than in those prescribed peramivir only. Patients who received add-on antibiotics had a significantly longer hospital stay (4.12 days) than those who received anti-influenza medicine only (3.77 days). In all age groups, the hospitalisation risk from pneumonia tended to be greater in those who received antibiotics than in those prescribed anti-influenza medicine only. However, among older patients (65-74 years), those provided add-on antibiotics had an average 5.24-day shorter hospitalisation due to pneumonia than those provided anti-influenza medicine only (not significant). Conclusions: In outpatient cases of influenza, patients who are prescribed antibiotics added to antiviral medicines have a higher risk of hospitalisation and longer duration of hospitalisation due to pneumonia.

Individual and Regional Characteristics Associated with Maternal Smoking During Pregnancy in Japan: Healthy Parents and Children 21.

Smoking during pregnancy causes various maternal and fetal health problems. Although there are considerable differences in maternal smoking proportions between localities, only a few studies have investigated the effects of regional characteristics on maternal smoking behavior. This study aimed to clarify the association between maternal smoking during pregnancy and individual and regional characteristics. We used data from a large nationwide birth cohort study in Japan that consisted of information on 20,267 women with children aged 3-4 months. The multilevel regression model was used to examine the association between smoking behavior during pregnancy and individual and regional characteristics. On multilevel analysis, late birth order, young age of the mother at birth, low birth weight, low economic status, husband's smoking during pregnancy, maternal alcohol consumption during pregnancy, absence of a pregnancy counselor, and lack of participation in local events for childrearing were significantly associated with maternal smoking behavior during pregnancy at the individual level. Meanwhile, a high unemployment rate and a high number of nurseries were significantly associated with maternal smoking behavior during pregnancy at the regional level. In conclusion, we showed the relation between maternal smoking during pregnancy and the individual- and regional-level characteristics.

[Association between time-appropriate vaccinations in early childhood and individual and community-level factors in Japan].

Objective　Recently, in Japan, the compulsory vaccinations administered during early childhood have been becoming increasingly varied. As a result, the vaccination schedule has become complicated. In this study, we aimed to identify the association of time-appropriate vaccination during early childhood (dependent variable) with individual-level factors including socioeconomic status and having a family doctor. We also studied the association of time-appropriate vaccination with community-level factors including the number of pediatricians in a community.Methods　Multilevel logistic regression models were used for analysis. Time-appropriate BCG, DPT, and measles vaccinations were the dependent variables. Individual-level data were obtained through a survey of parents of 18-month-old children as part of the final evaluation of "Healthy Parents and Children 21"; community-level data were obtained through a survey of municipalities as part of the aforementioned final evaluation as well as through a national survey. There were 23,583 parents in 430 municipalities who were eligible for analysis.Results　Time-appropriate vaccination of infants was carried out by 88.3% of parents. The results of the multilevel logistic regression showed that time-appropriate vaccination was significantly lower for those who did not have a family doctor (adjusted odds ratio [AOR], 0.45; 95% confidence interval [CI], 0.36-0.55), the fourth or later birth order (0.23; 0.19-0.28), mothers aged less than 19 years at childbirth (0.17; 0.13-0.24), full-time working mothers (0.52; 0.47-0.58), and those under very difficult economic conditions (0.66; 0.57-0.77). Among community-level factors, only use of vaccination data by a municipality had a significantly negative association with the dependent variable.Conclusion　Not having a family doctor, the mother's young age, late birth order, poor economic status, and full-time working mothers were risk factors associated with delayed vaccinations. It is necessary to improve environments that promote infants having a family doctor as well as to promote special approaches toward families at risk for delayed vaccinations.