Smoking remains associated with education after controlling for social background and genetic factors in a study of 18 twin cohorts.

We tested the causality between education and smoking using the natural experiment of discordant twin pairs allowing to optimally control for background genetic and childhood social factors. Data from 18 cohorts including 10,527 monozygotic (MZ) and same-sex dizygotic (DZ) twin pairs discordant for education and smoking were analyzed by linear fixed effects regression models. Within twin pairs, education levels were lower among the currently smoking than among the never smoking co-twins and this education difference was larger within DZ than MZ pairs. Similarly, education levels were higher among former smoking than among currently smoking co-twins, and this difference was larger within DZ pairs. Our results support the hypothesis of a causal effect of education on both current smoking status and smoking cessation. However, the even greater intra-pair differences within DZ pairs, who share only 50% of their segregating genes, provide evidence that shared genetic factors also contribute to these associations.

[Covid-19 and clinical-epidemiological research in Italy: proposal of a research agenda on priority topics by the Italian association of epidemiology]. / Covid-19 e ricerca clinico-epidemiologica in Italia: proposta di un'agenda di ricerca su temi prioritari da parte dell'Associazione italiana di epidemiologia.

BACKGROUND: the Covid-19 pandemic has provoked a huge of clinical and epidemiological research initiatives, especially in the most involved countries. However, this very large effort was characterized by several methodological weaknesses, both in the field of discovering effective treatments (with too many small and uncontrolled trials) and in the field of identifying preventable risks and prognostic factors (with too few large, representative and well-designed cohorts or case-control studies). OBJECTIVES: in response to the fragmented and uncoordinated research production on Covid-19, the   italian Association of Epidemiology (AIE) stimulated the formation of a working group (WG) with the aims of identifying the most important gaps in knowledge and to propose a structured research agenda of clinical and epidemiological studies considered at high priority on Covid-19, including recommendations on the preferable methodology. METHODS: the WG was composed by 25 subjects, mainly epidemiologists, statisticians, and other experts in specific fields, who have voluntarily agreed to the proposal. The agreement on a list of main research questions and on the structure of the specific documents to be produced were defined through few meetings and cycles of document exchanges. RESULTS: twelve main research questions on Covid-19 were identified, covering aetiology, prognosis, interventions, follow-up and impact on general and specific populations (children, pregnant women). For each of them, a two-page form was developed, structured in: background, main topics, methods (with recommendations on preferred study design and warnings for bias prevention) and an essential bibliography. CONCLUSIONS: this research agenda represents an initial contribution to direct clinical and epidemiological research efforts on high priority topics with a focus on methodological aspects. Further development and refinements of this agenda by Public Health Authorities are encouraged.

Piccolipiù, a multicenter birth cohort in Italy: protocol of the study.

BACKGROUND: The fetal and infant life are periods of rapid development, characterized by high susceptibility to exposures. Birth cohorts provide unique opportunities to study early-life exposures in association with child development and health, as well as, with longer follow-up, the early life origin of adult diseases. Piccolipiù is an Italian birth cohort recently set up to investigate the effects of environmental exposures, parental conditions and social factors acting during pre-natal and early post-natal life on infant and child health and development. We describe here its main characteristics. METHODS/DESIGN: Piccolipiù is a prospective cohort of expected 3000 newborns, who will be recruiting in six maternity units of five Italian cities (Florence, Rome, Trieste, Turin and Viareggio) since October 2011. Mothers are contacted during pregnancy or at delivery and are offered to participate in the study. Upon acceptance, their newborns are recruited at birth and followed up until at least 18 years of age. At recruitment, the mothers donate a blood sample and complete a baseline questionnaire. Umbilical cord blood, pieces of umbilical cord and heel blood spots are also collected. Postnatal follow-up currently occurs at 6, 12, and 24 months of age using on-line or postal self administered questionnaire; further questionnaires and medical examinations are envisaged. Questionnaires collect information on several factors, including mother's and/or child's environmental exposures, anthropometric measures, reproductive factors, diet, supplements, medical history, cognitive development, mental health and socioeconomic factors. Health promotion materials are also offered to parents. DISCUSSION: Piccolipiù will broaden our understanding of the contribution of early-life factors to infant and child health and development. Several hypotheses on the developmental origins of health can be tested or piloted using the data collected from the Piccolipiù cohort. By pooling these data with those collected by other existing birth cohorts it will be possible to validate previous findings and to study rare exposures and outcomes.