Laura Jones

Parental and household smoking and the increased risk of bronchitis, bronchiolitis and other lower respiratory infections in infancy: systematic review and meta-analysis.

BackgroundPassive smoke exposure increases the risk of lower respiratory infection (LRI) in infants, but the extensive literature on this association has not been systematically reviewed for nearly ten years. The aim of this paper is to provide an updated systematic review and meta-analysis of studies of the association between passive smoking and LRI, and with diagnostic subcategories including bronchiolitis, in infants aged two years and under.MethodsWe searched MEDLINE and EMBASE (to November 2010), reference lists from publications and abstracts from major conference proceedings to identify all relevant publications. Random effect pooled odds ratios (OR) with 95% confidence intervals (CI) were estimated.ResultsWe identified 60 studies suitable for inclusion in the meta-analysis. Smoking by either parent or other household members significantly increased the risk of LRI; odds ratios (OR) were 1.22 (95% CI 1.10 to 1.35) for paternal smoking, 1.62 (95% CI 1.38 to 1.89) if both parents smoked, and 1.54 (95% CI 1.40 to 1.69) for any household member smoking. Pre-natal maternal smoking (OR 1.24, 95% CI 1.11 to 1.38) had a weaker effect than post-natal smoking (OR 1.58, 95% CI 1.45 to 1.73). The strongest effect was on bronchiolitis, where the risk of any household smoking was increased by an OR of 2.51 (95% CI 1.96 to 3.21).ConclusionsPassive smoking in the family home is a major influence on the risk of LRI in infants, and especially on bronchiolitis. Risk is particularly strong in relation to post-natal maternal smoking. Strategies to prevent passive smoke exposure in young children are an urgent public and child health priority.

Parental Smoking and the Risk of Middle Ear Disease in Children A Systematic Review and Meta-analysis

OBJECTIVE A systematic review and meta-analysis of studies of the association between secondhand tobacco smoke (SHTS) and middle ear disease (MED) in children. DATA SOURCES MEDLINE, EMBASE, and CAB abstracts (through December 2010) and reference lists. STUDY SELECTION Sixty-one epidemiological studies of children assessing the effect of SHTS on outcomes of MED. Articles were reviewed, and the data were extracted and synthesized by 2 researchers. MAIN OUTCOME EXPOSURES: Childrens SHTS exposure. MAIN OUTCOME MEASURES Middle ear disease in children. RESULTS Living with a smoker was associated with an increased risk of MED in children by an odds ratio (OR) of 1.62 (95% CI, 1.33-1.97) for maternal postnatal smoking and by 1.37 (95% CI, 1.25-1.50) for any household member smoking. Prenatal maternal smoking (OR, 1.11; 95% CI, 0.93-1.31) and paternal smoking (OR, 1.24; 95% CI, 0.98-1.57) were associated with a nonsignificant increase in the risk of MED. The strongest effect was on the risk of surgery for MED, where maternal postnatal smoking increased the risk by an OR of 1.86 (95% CI, 1.31-2.63) and paternal smoking by 1.83 (95% CI, 1.61-2.07). CONCLUSIONS Exposure to SHTS, particularly to smoking by the mother, significantly increases the risk of MED in childhood; this risk is particularly strong for MED requiring surgery. We have shown that per year 130 200 of child MED episodes in the United Kingdom and 292 950 of child frequent ear infections in the United States are directly attributable to SHTS exposure in the home.

Age at menarche and the evidence for a positive secular trend in urban South Africa.

Menarcheal age was estimated for 287 (188 Black; 99 White) urban South African girls born in Soweto‐Johannesburg in 1990. The median menarcheal age for Blacks was 12.4 years (95% confidence interval (CI) 12.2, 12.6) and 12.5 years (95% CI 11.7, 13.3) for Whites. Data from six studies of menarcheal age, including the current study, were analyzed to examine the evidence for a secular trend between 1956 and 2004 in urban South African girls. There was evidence of a statistically significant secular trend for Blacks, but not Whites. Average menarcheal age for Blacks decreased from 14.9 years (95% CI 14.8, 15.0) in 1956 to 12.4 years (95% CI 12.2, 12.6) in the current study, an average decline of 0.50 years per decade. Fewer data were available for Whites, but average menarcheal age decreased from 13.1 years (95% CI 13.0, 13.2) in 1977 to 12.5 years (95% CI 11.7, 13.3) in the current study, an average decline of 0.22 years per decade. The diminishing age at menarche and the current lack of difference between Blacks and Whites is probably reflective of the continuing nutritional and socio‐economic transition occurring within South Africa. Am. J. Hum. Biol., 2009.

The Motivators and Barriers to a Smoke-Free Home Among Disadvantaged Caregivers: Identifying the Positive Levers for Change

INTRODUCTION The aims of this study were to explore home smoking behaviors and the motivators and barriers to smoke-free homes among a group of disadvantaged caregivers for young children and to identify the positive levers that health care professionals can utilize when supporting smoking behavior change. METHODS In-depth qualitative interviews were conducted between July and September 2009, with 22 disadvantaged smoking caregivers, accessing Childrens Centre Services in Nottingham, UK. Interviews were audiorecorded and transcribed verbatim. Data were coded and analyzed thematically to identify emergent main and subthemes. RESULTS Caregivers had some general understanding of the dangers of secondhand smoke (SHS), but their knowledge appeared incomplete and confused. All interviewees described rules around smoking in the home; however, these tended to be transient and fluid and unlikely to be effective. Caregivers were often living in difficult and complex circumstances and experienced significant barriers to creating a smoke-free home. The motivators for change were more strongly linked to house decor and smell than childrens health, suggesting that visible evidence of the harm done by SHS to children might help promote smoke-free homes. CONCLUSIONS Findings suggest that further tailored information on the effect of SHS is required, but to instigate caregiver behavior change, providing demonstrable evidence of the impact that their smoking is having on their childrens health is more likely to be effective.

Predictors of Children's Secondhand Smoke Exposure at Home: A Systematic Review and Narrative Synthesis of the Evidence

Background Childrens exposure to secondhand smoke (SHS) has been causally linked to a number of childhood morbidities and mortalities. Over 50% of UK children whose parents are smokers are regularly exposed to SHS at home. No previous review has identified the factors associated with childrens SHS exposure in the home. Aim To identify by systematic review, the factors which are associated with childrens SHS exposure in the home, determined by parent or child reports and/or biochemically validated measures including cotinine, carbon monoxide or home air particulate matter. Methods Electronic searches of MEDLINE, EMBASE, PsychINFO, CINAHL and Web of Knowledge to July 2014, and hand searches of reference lists from publications included in the review were conducted. Findings Forty one studies were included in the review. Parental smoking, low socioeconomic status and being less educated were all frequently and consistently found to be independently associated with childrens SHS exposure in the home. Children whose parents held more negative attitudes towards SHS were less likely to be exposed. Associations were strongest for parental cigarette smoking status; compared to children of non-smokers, those whose mothers or both parents smoked were between two and 13 times more likely to be exposed to SHS. Conclusion Multiple factors are associated with child SHS exposure in the home; the best way to reduce child SHS exposure in the home is for smoking parents to quit. If parents are unable or unwilling to stop smoking, they should instigate smoke-free homes. Interventions targeted towards the socially disadvantaged parents aiming to change attitudes to smoking in the presence of children and providing practical support to help parents smoke outside the home may be beneficial.

Polygenic interactions with environmental adversity in the aetiology of major depressive disorder

Background Major depressive disorder (MDD) is a common and disabling condition with well-established heritability and environmental risk factors. Gene–environment interaction studies in MDD have typically investigated candidate genes, though the disorder is known to be highly polygenic. This study aims to test for interaction between polygenic risk and stressful life events (SLEs) or childhood trauma (CT) in the aetiology of MDD. Method The RADIANT UK sample consists of 1605 MDD cases and 1064 controls with SLE data, and a subset of 240 cases and 272 controls with CT data. Polygenic risk scores (PRS) were constructed using results from a mega-analysis on MDD by the Psychiatric Genomics Consortium. PRS and environmental factors were tested for association with case/control status and for interaction between them. Results PRS significantly predicted depression, explaining 1.1% of variance in phenotype (p = 1.9 × 10−6). SLEs and CT were also associated with MDD status (p = 2.19 × 10−4 and p = 5.12 × 10−20, respectively). No interactions were found between PRS and SLEs. Significant PRSxCT interactions were found (p = 0.002), but showed an inverse association with MDD status, as cases who experienced more severe CT tended to have a lower PRS than other cases or controls. This relationship between PRS and CT was not observed in independent replication samples. Conclusions CT is a strong risk factor for MDD but may have greater effect in individuals with lower genetic liability for the disorder. Including environmental risk along with genetics is important in studying the aetiology of MDD and PRS provide a useful approach to investigating gene–environment interactions in complex traits.

Restriction of HIV-1 Genotypes in Breast Milk Does Not Account for the Population Transmission Genetic Bottleneck That Occurs following Transmission

Background Breast milk transmission of HIV-1 remains a major route of pediatric infection. Defining the characteristics of viral variants to which breastfeeding infants are exposed is important for understanding the genetic bottleneck that occurs in the majority of mother-to-child transmissions. The blood-milk epithelial barrier markedly restricts the quantity of HIV-1 in breast milk, even in the absence of antiretroviral drugs. The basis of this restriction and the genetic relationship between breast milk and blood variants are not well established. Methodology/Principal Findings We compared 356 HIV-1 subtype C gp160 envelope (env) gene sequences from the plasma and breast milk of 13 breastfeeding women. A trend towards lower viral population diversity and divergence in breast milk was observed, potentially indicative of clonal expansion within the breast. No differences in potential N-linked glycosylation site numbers or in gp160 variable loop amino acid lengths were identified. Genetic compartmentalization was evident in only one out of six subjects in whom contemporaneously obtained samples were studied. However, in samples that were collected 10 or more days apart, six of seven subjects were classified as having compartmentalized viral populations, highlighting the necessity of contemporaneous sampling for genetic compartmentalization studies. We found evidence of CXCR4 co-receptor using viruses in breast milk and blood in nine out of the thirteen subjects, but no evidence of preferential localization of these variants in either tissue. Conclusions/Significance Despite marked restriction of HIV-1 quantities in milk, our data indicate intermixing of virus between blood and breast milk. Thus, we found no evidence that a restriction in viral genotype diversity in breast milk accounts for the genetic bottleneck observed following transmission. In addition, our results highlight the rapidity of HIV-1 env evolution and the importance of sample timing in analyses of gene flow.

Is puberty starting earlier in urban South Africa

Age at the initation of pubertal development was estimated for 401 Black (212 boys) and 206 White (100 boys) urban South African adolescents born in Soweto‐Johannesburg in 1990. Average age at the initation of puberty, assessed by age at the transition from Tanner Stage 1 to Tanner Stage 2 for breast/genitalia or pubic hair development ranged between 9.8 and 10.5 years. There were no statistically significant differences in age at initiation between genders or ethnic groups. Age at the initation of pubertal development has remained stable over the last 10 to 15 years, with the exception of pubic hair in boys which has declined on average 1.3 years over a decade. There is evidence to suggest that the tempo of pubertal maturation is increasing in girls born in the Soweto‐Johannesburg area, however, the evidence is less clear for boys. Am. J. Hum. Biol., 2009.

The use of qualitative methods to inform Delphi surveys in core outcome set development

BackgroundCore outcome sets (COS) help to minimise bias in trials and facilitate evidence synthesis. Delphi surveys are increasingly being used as part of a wider process to reach consensus about what outcomes should be included in a COS. Qualitative research can be used to inform the development of Delphi surveys. This is an advance in the field of COS development and one which is potentially valuable; however, little guidance exists for COS developers on how best to use qualitative methods and what the challenges are. This paper aims to provide early guidance on the potential role and contribution of qualitative research in this area. We hope the ideas we present will be challenged, critiqued and built upon by others exploring the role of qualitative research in COS development.This paper draws upon the experiences of using qualitative methods in the pre-Delphi stage of the development of three different COS. Using these studies as examples, we identify some of the ways that qualitative research might contribute to COS development, the challenges in using such methods and areas where future research is required.ResultsQualitative research can help to identify what outcomes are important to stakeholders; facilitate understanding of why some outcomes may be more important than others, determine the scope of outcomes; identify appropriate language for use in the Delphi survey and inform comparisons between stakeholder data and other sources, such as systematic reviews. Developers need to consider a number of methodological points when using qualitative research: specifically, which stakeholders to involve, how to sample participants, which data collection methods are most appropriate, how to consider outcomes with stakeholders and how to analyse these data. A number of areas for future research are identified.ConclusionsQualitative research has the potential to increase the research community’s confidence in COS, although this will be dependent upon using rigorous and appropriate methodology. We have begun to identify some issues for COS developers to consider in using qualitative methods to inform the development of Delphi surveys in this article.

How well do waist circumference and body mass index reflect body composition in pre-pubertal children?

Objective:To investigate the quantitative relationship between waist circumference (WC) and height (Ht), and subsequently the association between waist circumference index (WCI), body mass index (BMI) and body composition in pre-pubertal children.Design:Cross-sectional sample (n=227; boys=127) of pre-pubertal black children (age range 8.8–11.0 years) from the Bone Health sub-study of the Bt20 birth cohort study set in Soweto-Johannesburg, South Africa. Measures of height, weight and WC by anthropometry, total and truncal fat and lean mass by dual-energy X-ray absorptiometry were used in the analysis. Pearsons correlation coefficients were used to examine the associations between BMI, WC and body composition outcomes.Results:WC was independent of height when height was raised to a power of ∼0.8. BMI and WCI (WC/Ht) were significantly associated with total and truncal fat and lean mass in both sexes (all P<0.001). BMI showed consistently and significantly higher correlations with body composition than WCI and this association was significantly greater for fat mass than lean mass.Conclusion:BMI, rather than WCI, would be a better screening tool for total and truncal fat mass in both sexes before puberty.