Smoking during pregnancy: changes and associated risk factors in Spain, 1980-2016.

BACKGROUND: Trends for maternal smoking rates have varied substantially across industrialized countries. The objective was to describe how the prevalence of maternal smoking evolved in Spain during 1980-2016. METHODS: Data came from the Spanish Collaborative Study of Congenital Malformations. Our sample consisted of 40 934 mothers of newborns with no congenital defects from hospitals all across Spain. We estimated change points in trend and the mean annual change in smoking prevalence using 'joinpoint' regression. Relevant potential factors (age, country of birth, education, parity, planned pregnancy and alcohol consumption) were examined using multivariate logistic regression. RESULTS: Maternal smoking prevalence in 1980 and 2016 were 14.3% (95% confidence interval [CI]: 11.9-17.0) and 20.4% (95% CI: 15.9-25.8). We identified four periods with distinct trends: a sharp increase during the 80s, a plateau during the 90s, a decrease starting in 2000 and a slowdown of such decrease from 2009 on. Smoking was significantly higher among young women, Spain-born, with low education, unplanned pregnancy, and alcohol consumption. CONCLUSIONS: Currently in Spain maternal smoking remains very high. Tobacco consumption trend showed an increase during the 80s, a plateau during the 90s, and a reduction in the 2000s. Several sociodemographic and behavioural factors were associated to greater likelihood of smoking.

The Effectiveness and Sero-Immunity of Hepatitis B Vaccination in People Who Use Drugs: A Systematic Review and Meta-Analysis.

Hepatitis B virus (HBV) vaccination has been available for over four decades. However, a synthesis of the evidence regarding the effectiveness of this strategy on preventing hepatitis B infection in people who use drugs (PWUD) is lacking. A systematic search of the MEDLINE (via PubMed), SCOPUS, Web of Science, and Cochrane Library databases was conducted up to June 2024. Eight studies reported on the effectiveness of HBV vaccination, defined as a positive result for HBsAg or anti-Hbc in vaccinated versus non-vaccinated PWUD, with a pooled effect size of 52% (95% CI: 28.2-67.9) for HBsAg and 31.89% (95% CI: 14.8-45.5) for anti-Hbc. For sero-immunity, defined as the proportion of vaccinated PWUD with levels of anti-HBs ≥ 10 mIU/mL, we found that 66.2% (95% CI: 0.61-0.71; I2 = 94%) had protective levels of anti-HBs. The results of this meta-analysis indicate that the incidence of HBV infection is lower in vaccinated PWUD than in those who did not receive the vaccine. However, the effectiveness is lower than that observed in the general population. This highlights the need for a thorough review of the factors influencing the prevention of HBV infection in PWUD.