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Thelaziosis is an emerging zoonotic disease caused by nematodes of the genus Thelazia (Spirurida, Thelazioidea). In the United States, 3 zoonotic species have been identified: Thelazia gulosa (1), T. californiensis [...]

A common problem in the analysis of multiple data sources, including individual participant data meta-analysis (IPD-MA), is the misclassification of binary variables. Misclassification may lead to biased estimators of model parameters, even when the misclassification is entirely random. We aimed to develop statistical methods that facilitate unbiased estimation of adjusted and unadjusted exposure-outcome associations and between-study heterogeneity in IPD-MA, where the extent and nature of exposure misclassification may vary across studies. We present Bayesian methods that allow misclassification of binary exposure variables to depend on study- and participant-level characteristics. In an example of the differential diagnosis of dengue using two variables, where the gold standard measurement for the exposure variable was unavailable for some studies which only measured a surrogate prone to misclassification, our methods yielded more accurate estimates than analyses naive with regard to misclassification or based on gold standard measurements alone. In a simulation study, the evaluated misclassification model yielded valid estimates of the exposure-outcome association, and was more accurate than analyses restricted to gold standard measurements. Our proposed framework can appropriately account for the presence of binary exposure misclassification in IPD-MA. It requires that some studies supply IPD for the surrogate and gold standard exposure, and allows misclassification to follow a random effects distribution across studies conditional on observed covariates (and outcome). The proposed methods are most beneficial when few large studies that measured the gold standard are available, and when misclassification is frequent.

Ideally, a meta-analysis will summarize data from several unbiased studies. Here we look into the less than ideal situation in which contributing studies may be compromised by non-differential measurement error in the exposure variable. Specifically, we consider a meta-analysis for the association between a continuous outcome variable and one or more continuous exposure variables, where the associations may be quantified as regression coefficients of a linear regression model. A flexible Bayesian framework is developed which allows one to obtain appropriate point and interval estimates with varying degrees of prior knowledge about the magnitude of the measurement error. We also demonstrate how, if individual-participant data (IPD) are available, the Bayesian meta-analysis model can adjust for multiple participant-level covariates, these being measured with or without measurement error.

A systematic review of longitudinal studies suggests that intimate partner violence (IPV) is associated with reduced contraceptive use, but most included studies were limited to two time points. We used seven waves of data from the Rakai Community Cohort Study in Rakai, Uganda to estimate the effect of prior year IPV at one visit on women's current contraceptive use at the following visit. We used inverse probability of treatment-weighted marginal structural models (MSMs) to estimate the relative risk of current contraceptive use comparing women who were exposed to emotional, physical, and/or sexual IPV during the year prior to interview to those who were not. We accounted for time-fixed and time-varying confounders and prior IPV and adjusted standard errors for repeated measures within individuals. The analysis included 7923 women interviewed between 2001 and 2013. In the weighted MSMs, women who experienced any form of prior year IPV were 20% less likely to use condoms at last sex than women who had not (95% CI: 0.12, 0.26). We did not find evidence that IPV affects current use of modern contraception (RR: 0.99; 95% CI: 0.95, 1.03); however, current use of a partner-dependent method was 27% lower among women who reported any form of prior-year IPV compared to women who had not (95% CI: 0.20, 0.33). Women who experienced prior-year IPV were less likely to use condoms and other forms of contraception that required negotiation with their male partners and more likely to use contraception that they could hide from their male partners. Longitudinal studies in Rakai and elsewhere have found that women who experience IPV have a higher rate of HIV than women who do not. Our finding that women who experience IPV are less likely to use condoms may help explain the relation between IPV and HIV.

IntroductionInadequately spaced pregnancies, defined as pregnancies fewer than 18 months apart, are linked to maternal, infant, and child morbidity and mortality, and adverse social, educational and economic outcomes in later life for women and children. Quantifying the relation between intimate partner violence (IPV) and women's ability to space and time their pregnancies is an important part of understanding the burden of disease related to IPV.MethodsWe applied Cox proportional hazards models to monthly data from the Demographic and Health Surveys' Reproductive Health Calendar to compare interpregnancy intervals for women who experienced physical, sexual and/or emotional IPV in 29 countries. We conducted a one-stage meta-analysis to identify the periods when women who experienced IPV were at the highest risk of unintended and incident pregnancy, and a two-stage meta-analysis to explore cross-country variations in the magnitude of the relation between women's experience of IPV and pregnancy spacing.ResultsFor the one-stage analysis, considering 52 959 incident pregnancies from 90 446 women, which represented 232 394 person-years at risk, women's experience of IPV was associated with a 51% increase in the risk of pregnancy (95% CI 1.38 to 1.66), although this association decreased over time. When limiting our inference to unintended pregnancies that resulted in live births, women's experience of IPV was associated with a 30% increase in the risk of unintended pregnancy (95% CI 1.25 to 1.34; n=13 541 pregnancies, 92 848 women, 310 319 person-years at risk). In the two-stage meta-analyses, women's experience of IPV was associated with a 13% increase in the probability of incident pregnancy (95% CI 1.07 to 1.20) and a 28% increase in the likelihood of unintended pregnancy (95% CI 1.19 to 1.38).ConclusionsAcross countries, women's experience of IPV is associated with a reduction in time between pregnancies and an increase in the risk of unintended pregnancy; the magnitude of this effect varied by country and over time.

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Individual participant data meta‐analyses (IPD‐MAs) have several benefits over standard aggregate data meta‐analyses, including the consideration of additional participants, follow‐up time, and the joint consideration of study‐ and participant‐level heterogeneity for improved diagnostic and prognostic model development and evaluation. However, IPD‐MAs are resource‐intensive and require careful budgeting of time from data contributing groups, a dedicated management team, diversity of expertise, clearly documented data sharing and authorship agreements, and consistent and clear communication. We present a toolkit to facilitate the implementation and management of IPD‐MAs, from study recruitment to retrospective harmonization. The toolkit was developed and refined over our work on multiple multinational IPD‐MA projects over the last 13 years. The toolkit's budget and email templates, agreements, project management spreadsheets, and standard operating procedures are meant to facilitate routine IPD‐MA tasks to expedite implementing and managing future IPD‐MA projects. [ABSTRACT FROM AUTHOR]

Background: Children who do not produce single words by the expected age have been described as "late talkers" or as demonstrating "late language emergence" (LLE). Although their short-term growth in vocabulary is often strong, longer-term consequences of LLE remain in dispute. It has been argued that the majority of school-age children who had LLE move into the average range for narrative production, though studies have not examined narrative comprehension. It has also been argued that school-age children with LLE score in the average range on standardized tests of syntax, though studies have not examined performance in conversational contexts. Aims: This article compared school-age children with and without histories of LLE for performance on standardized narrative comprehension and production tasks, as well as the use of complex sentences and relative clauses in narration and conversation. Both complex syntax and relative clause use are reduced in children with specific language impairment (SLI), so these structures may be useful as indicators of linguistic weakness. Methods & Procedures: The participants were twenty-two 8-year-old children, divided into two groups. Eleven children who had been diagnosed with LLE at 30 months were compared with a control group of 11 children with typical development (TD). All participants completed a standardized test of narrative comprehension and production and a 10-min conversational sample. Both narrative and conversational samples were analysed for the number of complex sentences and relative clauses. Outcomes & Results: Overall results indicated that children with a history of LLE did not have comprehension or production scores that were significantly different from the TD group on the standardized narrative test; nor did groups differ for production of complex sentences or relative clauses in narrative samples. However, a significant difference was found for the production of complex sentences in conversational samples, with the children diagnosed with LLE producing fewer complex sentences than the TD group. There was no difference between groups for relative clause use in conversation or in narratives. Conclusions & Implications: These data suggest that children with a history of LLE may exhibit age-appropriate performance on a standardized narrative test, but still lack the syntactic complexity of their TD peers in conversation. Assessments for school-age children with a history of language delay should include analysis of syntactic complexity in conversation to identify continuing weakness. Future research should examine use of other specific types of complex structures (e.g. infinitival and clausal complements) in this population, as well the feasibility of increasing complex sentence production through intervention. In addition, future studies should examine whether this decreased production of complex syntax in conversation is noted by naive listeners. (Contains 1 table.)