Complex Study Designs Research Articles

Who is in this study, anyway? Guidelines for a useful Table 1

ObjectiveEpidemiologic and clinical research papers often describe the study sample in the first table. If well-executed, this “Table 1” can illuminate potential threats to internal and external validity. However, little guidance exists on best practices for designing a Table 1, especially for complex study designs and analyses. We aimed to summarize and extend the literature related to reporting descriptive statistics. Study Design and SettingIn consultation with existing guidelines, we synthesized and developed reporting recommendations driven by study design and focused on transparency related to potential threats to internal and external validity. ResultsWe describe a basic structure for Table 1 and discuss simple modifications in terms of columns, rows, and cells to enhance a reader's ability to judge both internal and external validity. We further highlight several analytic complexities common in epidemiologic research (missing data, sample weights, clustered data, and interaction) and describe possible variations to Table 1 to maintain and add clarity about study validity in light of these issues. We discuss considerations and tradeoffs in Table 1 related to breadth and comprehensiveness vs. parsimony and reader-friendliness. ConclusionWe anticipate that our work will guide authors considering layouts for Table 1, with attention to the reader's perspective.

Abstract P372: Association of Cardiovascular Disease Family History With Major Cardiovascular Risk Factors in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Introduction: Family history (FH) is a well-known risk factor for cardiovascular disease (CVD); however, the association of FH with CVD in Hispanic/Latino populations has not been well investigated. We examined the cross-sectional association of FH of CVD or CVD risk factors with individual CVD risk factors (hypertension, hypercholesterolemia, obesity, diabetes mellitus, and smoking), CVD risk profile, and prevalence of CHD or stroke in the HCHS/SOL. Methods: Baseline data on FH and CVD risk factors from 15,104 HCHS/SOL participants were analyzed. Self-reported first-degree FH of high blood pressure (BP), high cholesterol, diabetes, angina, heart attack, heart failure, rheumatic heart disease, angioplasty/bypass, stroke, aortic aneurysm, and peripheral artery disease was ascertained and categorized as any first-degree FH vs. no FH of each condition. Hypertension, high cholesterol, obesity and diabetes mellitus were ascertained by objective measures and/or medication use; smoking was self-reported. The CVD risk profile was calculated by assigning a score of 0 to 5 based on the number of adverse CVD risk factors. Analysis of CVD risk factors was dichotomized as low (0 and 1 risk factor) vs. high (2+ risk factors). Odds ratios and 95% confidence intervals were derived from logistic regression models, accounting for the complex study design and controlling for multiple covariates. Results: Prevalence of CVD risk factors and risk profile were associated with self-reported FH (see Table). Furthermore, prevalence of CHD was associated with FH of high BP, high cholesterol, diabetes, angina, heart attack, heart failure, and rheumatic heart disease. Personal history of stroke was associated with FH of high BP, angina, and aortic aneurysm. Conclusions: First-degree FH of CVD factors and diseases was associated with hypertension, high cholesterol, obesity, diabetes, CHD and stroke among Hispanics/Latinos in HCHS/SOL. Ascertainment of FH should be an integral part of CVD risk assessment in Hispanics/Latinos in the US.

Rapid Assessment of Olfactory Sensitivity Using the \u201cSniffin\u2019 Sticks\u201d

IntroductionAssessment of olfactory performance is of high clinical interest in the contexts of smell loss as well as neurological diseases, and recently gained attention in obesity research. Available olfactory tests, especially for assessing olfactory sensitivity, are time-consuming and require high cognitive capacity. Therefore, we aimed to establish a short procedure for reliably testing olfactory sensitivity using a subtest of the “Sniffin’ Sticks” battery. Evaluation criteria are test duration, validity, and test-retest reliability.MethodsIn a preliminary study using a within-subject repeated-measures design, we measured olfactory sensitivity for n-butanol in 20 young and healthy participants. We compared sensitivity obtained with three different measures during two sessions in a pseudo-randomized order: a standard single-staircase three-alternative forced-choice procedure with seven reversals (SSP_7); an abbreviated version with five reversals (SSP_5); and an ascending presentation of 16 dilution steps from lowest to highest odor concentration (brief ascending procedure, BAP).ResultsCompared to the SSP_7, the BAP was 51%, and the SSP_5 26% shorter in duration. Both the BAP and SSP_5 scores were highly correlated with the SSP_7. The test-retest reliability in all three tests was similar to that typically reported in olfactory research.ConclusionThe abbreviated tests are valid measures of olfactory sensitivity. Especially, the BAP is as reliable as the standard method, but remarkably faster and easier to perform.ImplicationsThus, the short procedures bear potential for both research and clinical practice, especially for complex study designs with time constraints on olfactory testing and for patient populations with attention deficits.

Development of an Electronic Data Collection System to Support a Large-Scale HIV Behavioral Intervention Trial: Protocol for an Electronic Data Collection System.

BackgroundAdvancing technology has increased functionality and permitted more complex study designs for behavioral interventions. Investigators need to keep pace with these technological advances for electronic data capture (EDC) systems to be appropriately executed and utilized at full capacity in research settings. Mobile technology allows EDC systems to collect near real-time data from study participants, deliver intervention directly to participants’ mobile devices, monitor staff activity, and facilitate near real-time decision making during study implementation.ObjectiveThis paper presents the infrastructure of an EDC system designed to support a multisite HIV biobehavioral intervention trial in Los Angeles and New Orleans: the Adolescent Medicine Trials Network “Comprehensive Adolescent Research & Engagement Studies” (ATN CARES). We provide an overview of how multiple EDC functions can be integrated into a single EDC system to support large-scale intervention trials.MethodsThe CARES EDC system is designed to monitor and document multiple study functions, including, screening, recruitment, retention, intervention delivery, and outcome assessment. Text messaging (short message service, SMS) and nearly all data collection are supported by the EDC system. The system functions on mobile phones, tablets, and Web browsers.ResultsATN CARES is enrolling study participants and collecting baseline and follow-up data through the EDC system. Besides data collection, the EDC system is being used to generate multiple reports that inform recruitment planning, budgeting, intervention quality, and field staff supervision. The system is supporting both incoming and outgoing text messages (SMS) and offers high-level data security. Intervention design details are also influenced by EDC system platform capabilities and constraints. Challenges of using EDC systems are addressed through programming updates and training on how to improve data quality.ConclusionsThere are three key considerations in the development of an EDC system for an intervention trial. First, it needs to be decided whether the flexibility provided by the development of a study-specific, in-house EDC system is needed relative to the utilization of an existing commercial platform that requires less in-house programming expertise. Second, a single EDC system may not provide all functionality. ATN CARES is using a main EDC system for data collection, text messaging (SMS) interventions, and case management and a separate Web-based platform to support an online peer support intervention. Decisions need to be made regarding the functionality that is crucial for the EDC system to handle and what functionality can be handled by other systems. Third, data security is a priority but needs to be balanced with the need for flexible intervention delivery. For example, ATN CARES is delivering text messages (SMS) to study participants’ mobile phones. EDC data security protocols should be developed under guidance from security experts and with formative consulting with the target study population as to their perceptions and needs.International Registered Report Identifier (IRRID)DERR1-10.2196/10777

Factors associated with under-five mortality in Bhutan: an analysis of the Bhutan National Health Survey 2012

BackgroundAs an important marker for health equity and access, under-five mortality (UFM) is a primary measure for socioeconomic development. The importance of reducing UFM has been further emphasized in an ambitious target under Sustainable Development Goals. The factors influencing UFM are not adequately understood in Bhutan.MethodsThe most recent dataset of the Bhutan National Health Survey (BNHS) 2012 was used in this study. Multiple logistic regression analysis using a backwards elimination approach was performed to identify significant factors influencing UFM. All statistical analyses were adjusted for the complex study design due to the multistage stratified cluster sampling used in BNHS.ResultsBhutan’s UFM rate was 37 per 1000 live births. The weighted mean age of the children was 7.3 years (SD: 1.53; range: 3–12). Mother’s age, household size, access to electricity and sanitation, residential region, and parity were the key factors associated with UFM. The UFM risk was significantly lower in children born to mothers aged 36–40 years, 41–45 years, and > 45 years when compared to that in children born to mothers aged < 26 years. The likelihood of mortality was 66% lower (95% CI: 0.21–0.55) among children born in households with > 5 members. Children born in households without electricity and safe sanitation had a significantly higher risk of death, by 81 and 49% respectively. Relative to those born in the west, children born in the central and eastern regions were 1.72 (95% CI: 1.07–2.77) and 2.09 (95% CI: 1.46–2.99) times more likely to die, respectively. Children born to mothers who gave birth to > 2 children were significantly more likely to die than their counterparts.ConclusionThese findings suggest that younger mother’s age, the higher number of births and being born in the central and eastern regions are associated with a higher UFM risk, whereas a larger household size and access to electricity and safe sanitation are key factors associated with lower UFM risk in Bhutan. Women empowerment, health education and strategies promoting maternal and child health in rural areas need to be scaled-up. Additionally, socioeconomic development programs should seek to reduce regional disparities.

On the Differential and Shared Effects of Leadership for Learning on Teachers’ Organizational Commitment and Job Satisfaction: A Multilevel Perspective

Purpose: Over the past years “leadership for learning” (LFL) has become popular among educational scholars. LFL refers to the idea that effective leaders demonstrate a contextually contingent mix of instructional, transformational, and shared leadership practices that may have differential effects at various organizational levels. These assumptions have rarely been investigated within a coherent empirical design. We examine the shared and differential effects of LFL on teachers’ job satisfaction and organizational commitment, which are relevant antecedents for learning, improvement, and change on all levels of a school. Method: Drawing on survey data ( nteachers = 3,746, nschools = 126) from Germany and on well-established instruments like the Multifactor Leadership Questionnaire or Teaching and Learning International Survey, multilevel associations of LFL and teachers’ job satisfaction and organizational commitment were explored. This was done by applying doubly latent structural equation models. Findings: Our results indicate that (1) it is statistically necessary to model perceived leadership practices as a multilevel construct, (2) shared leadership is a strong predictor of individual and shared job satisfaction and organizational commitment of teachers whereas (3) individual consideration only shows significant associations on the individual level (4) that LFL is contextually sensitive. Implications for Research and Practice: Findings make a strong case for studying LFL within a multilevel framework and also for applying complex study and analytical designs, which should take the complexity of the theoretical assumptions into consideration all the way along from questionnaire design, through the process of data collection up to the point of data analysis.

Physical activity and weight maintenance: the utility of wearable devices and mobile health technology in research and clinical settings.

The integration of wearable devices and mobile health (mHealth) technology to facilitate behavior change has the potential to transform the efficacy of interventions and implementation programs for weight maintenance. The purpose of this review was to provide a comprehensive analysis of the overall utility of wearable devices for assessing and promoting weight maintenance in research and clinical settings. Recent intervention trials using wearable devices have been successful in increasing physical activity and decreasing or maintaining body weight, but complex study designs involving multiple behavioral strategies make it difficult to assess whether wearable devices can independently influence weight status. The daily feedback that wearable devices and mHealth technology provide may assist in motivating higher levels of physical activity achievement. However, the integration of wearable devices into the healthcare setting and implementation of mHealth programs still need to be tested. Recent studies add concrete implications for providers and researchers to better assess and promote physical activity in healthcare settings by identifying how wearable devices can be advantageous for physical activity and health promotion.

Sind autonome Kliniken die besseren Forschungsstandorte? Einfluss von Eigenständigkeit auf Publikationsleistung und Studientypen in der akademischen Plastischen Chirurgie

Despite its increasing acceptance as an autonomous specialty the field of plastic surgery remains underrepresented in terms of independent departments with a dedicated research infrastructure. The objective of this study was to analyze the current quantitative and qualitative publication performance of academic plastic surgery in Germany in order to compare independent departments and subordinate organizational structures regarding their scientific efficiency. Via a pubmed analysis the publication performance between 2014 and 2015 was analyzed. In a publication content analysis potential differences in the publications' quality were assessed. The majority of publications (81 %) and of the cumulative impact factor (87 %) were created within the independent departments. Top-publications with an impact factor > 5 were published in departments only. The qualitative content analysis displayed a varying research-focus in the different organizational structures. Whereas in departments 50 % of publications were experimental, clinical-experimental or clinical, in subordinate organizational structures a major focus lay on retrospective-statistical work with 24 % in contrast to 10 % in independent departments. This study demonstrates that the type of organizational structure could be a major influencing factor on the publication performance in German academic plastic surgery. An increased autonomy of an academic plastic surgery unit will most likely improve the publication performance and quality and could lead to a more complex study design.

PBMC fixation and processing for Chromium single-cell RNA sequencing

BackgroundInterest in single-cell transcriptomic analysis is growing rapidly, especially for profiling rare or heterogeneous populations of cells. In almost all reported works investigators have used live cells, which introduces cell stress during preparation and hinders complex study designs. Recent studies have indicated that cells fixed by denaturing fixative can be used in single-cell sequencing, however they did not usually work with most types of primary cells including immune cells.MethodsThe methanol-fixation and new processing method was introduced to preserve human peripheral blood mononuclear cells (PBMCs) for single-cell RNA sequencing (scRNA-Seq) analysis on 10× Chromium platform.ResultsWhen methanol fixation protocol was broken up into three steps: fixation, storage and rehydration, we found that PBMC RNA was degraded during rehydration with PBS, not at cell fixation and up to 3-month storage steps. Resuspension but not rehydration in 3× saline sodium citrate (SSC) buffer instead of PBS preserved PBMC RNA integrity and prevented RNA leakage. Diluted SSC buffer did not interfere with full-length cDNA synthesis. The methanol-fixed PBMCs resuspended in 3× SSC were successfully implemented into 10× Chromium standard scRNA-seq workflows with no elevated low quality cells and cell doublets. The fixation process did not alter the single-cell transcriptional profiles and gene expression levels. Major subpopulations classified by marker genes could be identified in fixed PBMCs at a similar proportion as in live PBMCs. This new fixation processing protocol also worked in several other fixed primary cell types and cell lines as in live ones.ConclusionsWe expect that the methanol-based cell fixation procedure presented here will allow better and more effective batching schemes for a complex single cell experimental design with primary cells or tissues.

Extracellular vesicles: a promising tool for assessment of embryonic competence.

Extracellular vesicles have recently emerged as a promising field of research due to their pivotal roles in intercellular communication and potential to serve as biomarkers. This review focuses on extracellular vesicles secreted by the human preimplantation embryo. The most recent findings on embryo-derived extracellular vesicles are described and discussed, as well as current technical challenges to study them. So far, only a few studies have addressed extracellular vesicles of embryonic origin and explored their potential as biomarkers for embryo selection. Two main hypotheses have driven interest in studying extracellular vesicles in IVF embryo-conditioned culture media. On the one hand, the potential roles of extracellular vesicles in mediating the embryo-endometrial crosstalk for proper implantation. On the other hand, the profile of secreted extracellular vesicles as an indicator of embryonic fitness irrespective of any involvement or communication with the endometrium. Embryo-derived extracellular vesicles have already been investigated to design diagnostic tests for embryo viability, however with small sample sizes or without extensive technology validation. Extracellular vesicles offer indeed a novel means to assess embryonic fitness. Further validation studies, technology development and more complex study designs are certainly required to implement the profiling of embryonic extracellular vesicles as a diagnostic test for embryo selection.

On the Use of Diversity Measures in Longitudinal Sequencing Studies of Microbial Communities.

Identification of the majority of organisms present in human-associated microbial communities is feasible with the advent of high throughput sequencing technology. As substantial variability in microbiota communities is seen across subjects, the use of longitudinal study designs is important to better understand variation of the microbiome within individual subjects. Complex study designs with longitudinal sample collection require analytic approaches to account for this additional source of variability. A common approach to assessing community changes is to evaluate the change in alpha diversity (the variety and abundance of organisms in a community) over time. However, there are several commonly used alpha diversity measures and the use of different measures can result in different estimates of magnitude of change and different inferences. It has recently been proposed that diversity profile curves are useful for clarifying these differences, and may provide a more complete picture of the community structure. However, it is unclear how to utilize these curves when interest is in evaluating changes in community structure over time. We propose the use of a bi-exponential function in a longitudinal model that accounts for repeated measures on each subject to compare diversity profiles over time. Furthermore, it is possible that no change in alpha diversity (single community/sample) may be observed despite the presence of a highly divergent community composition. Thus, it is also important to use a beta diversity measure (similarity between multiple communities/samples) that captures changes in community composition. Ecological methods developed to evaluate temporal turnover have currently only been applied to investigate changes of a single community over time. We illustrate the extension of this approach to multiple communities of interest (i.e., subjects) by modeling the beta diversity measure over time. With this approach, a rate of change in community composition is estimated. There is a need for the extension and development of analytic methods for longitudinal microbiota studies. In this paper, we discuss different approaches to model alpha and beta diversity indices in longitudinal microbiota studies and provide both a review of current approaches and a proposal for new methods.

An update on the clinical evidence that supports biosimilar approvals in Europe.

AimSponsors and regulators have more than 10 years of experience with the development of biosimilars in Europe. However, the regulatory pathway is still evolving. The present article provides an update on biosimilar development in practice by reviewing the clinical development programmes of recently approved biosimilars in Europe.MethodsWe used the European public assessment reports (EPARs) which are published by the European Medicines Agency (EMA) for a comparison of the clinical development programmes of the 37 approved biosimilars in Europe. Here, we present novel strategies in the development of biosimilars by focusing specifically on the 17 biosimilars that have gained approval in the last year, but we also compare additional key characteristics for all approved biosimilars.ResultsThe high variability of the clinical development strategies that we found previously was confirmed in the present analysis. Compared with earlier biosimilar applications, more nonstandard development strategies have been used recently. This includes, for example, applications without any studies in patients, and more complex study designs. During this study, we found that the EPARs for biosimilars seem to be improving; however, we identified important details which were still often missing. We provide a proposal for a checklist of the minimum information that should be included in biosimilar EPARs for giving the general public insights into the rationale for the approval of biosimilars.ConclusionsEuropean regulators still seem to be open to consider approaches that differ from the guidelines or previous applications, as long as justification is provided.

An Environmental influences on Child Health Outcomes viewpoint of data analysis centers for collaborative study designs.

A highly complex collaborative study design that pools and extends existing studies, such as the Environmental influences on Child Health Outcomes (ECHO) Program, requires a Data Analysis Center (DAC) with resources and expertise to create a secure environment for housing and analyzing the shared data, harmonize and structure the shared data for different purposes, and apply appropriate and innovative designs and analytic methods. The DAC, in partnership with cohort investigators, must ensure that results from ECHO-wide cohort analyses are appropriately interpreted and reproducible. Understanding the cohorts contributing to ECHO is critical for developing a collaborative environment and the methods to best analyze the data without bias. We further describe the development of the ECHO-wide cohort Metadata Catalog, the architecture of the ECHO-wide cohort data platform, and analytical approaches to facilitate early productivity. The ECHO DAC has established a secure environment for the transfer and storage of ECHO cohort data and information, and initiated processes to promote productive collaborations. Understanding the ECHO DAC responsibilities and assets will help to overcome communication and trust challenges encountered in the initiation of this complex ECHO-wide cohort collaborative research study.

Abstract P328: Cardiovascular Disease and Risk Factors Are Associated With Poor Health-Related Quality of Life Among Hispanic/Latino Adults With Arthritis Symptoms: Findings From the Hispanic Community Health Study/ Study of Latinos

Introduction: Despite greater longevity, Hispanics/Latinos have shorter functional limitations-free life and greater prevalence of arthritis-attributable functional limitations compared to non-Hispanic Whites. We assessed the hypothesis that CVD and CVD risk factors (RFs) are independently associated with poor health-related quality of life (HRQOL) among Hispanics/Latinos with arthritis. Methods: HCHS/SOL is a multi-center prospective population-based study of 16,415 diverse Hispanic/Latino adults ages 18-74 years at baseline (2008-11). Data from 2,083 men and women with self-reported arthritis-related symptoms were analyzed. Self-reported HRQOL was assessed using the 12-item Short-Form (SF-12) survey: self-reported health status (fair/poor vs. excellent/very good/good); and physical and mental health component summary scores (PCS and MCS; standardized z scores ranging from 0-100; higher scores indicate better HRQOL). Prevalent CVD (yes/ no) was defined using Framingham CVD Composite Criterion. CVD RFs were diabetes, obesity, hypercholesterolemia, hypertension, smoking, and physical activity. Logistic and linear regression models were used to examine cross-sectional associations of CVD and CVD RFs with HRQOL, after adjustment for relevant covariates and other CVD or CVD RFs. All analyses accounted for the complex study design. Results: In multivariable-adjusted models, CVD, diabetes, and current smoking were associated with 1.73, 2.04, and 1.48 times higher odds of fair/poor general health, compared to absence of CVD, normal glycemic status, and never-smoking, respectively. CVD, diabetes, obesity, physical inactivity, and low activity were associated with lower PCS scores. CVD, obesity, overweight, and current and former smoking were associated with lower MCS scores ( Table ). Conclusions: CVD and CVD RFs are independently associated with poorer HRQOL among Hispanic/Latino adults with arthritis, suggesting presence of unmet health and lifestyle management needs in this group.

Abstract P264: Six-Year Incidence of Overweight and Obesity Among Diverse Hispanic/Latino Adults in the US: The Hispanic Community Health Study/ Study of Latinos

Baseline HCHS/SOL data recently showed that prevalence of obesity varied markedly by sex and Hispanic/Latino background. Despite increasing prevalence of obesity in the US, little data exist on incidence of overweight and obesity in diverse US Hispanic/Latino adults. This study examined ~6-year incidence rate of overweight and obesity in this population by demographic factors. Methods: HCHS/SOL is a multi-center prospective community-based study of 16,415 diverse Hispanic/Latino adults in the US, ages 18-74 at Visit 1 (2008-11). Visit 2 (2014-17) is ongoing, with 10,914 persons reexamined by August 2017. Analyses included 10,427 persons with complete data on body mass index (BMI) at both visits and on other variables of interest; underweight persons were excluded. Age-adjusted incidence rate of overweight (BMI 25.0-29.9 kg/m 2 ; among those normal-weight at baseline), and obesity (BMI &gt; 30 kg/m 2 ; in those non-obese at baseline) was computed by sex and Hispanic/Latino background, accounting for the complex study design. Results: In ~6 years, 572 and 765 new cases of overweight and obesity were seen among baseline normal-weight (n=1924) and non-obese (n=5912) participants, respectively. Among men and women, age-adjusted incidence of overweight was 5.45 and 5.33 per 100 person years (PY); age-adjusted obesity incidence was 2.00 and 2.56 /100 PY. Incidence rates varied by background. Among men, overweight incidence was highest in those of Mexican background (6.95 /100 PY), and among women, in those of Puerto Rican background (6.94/ 100 PY). Incidence of obesity was highest in Dominican-background men (2.35/ 100 PY) and Cuban-background women (3.85/ 100 PY) ( Table ). Incidence rates varied slightly by age group, from 4.06 to 5.98/100 PY in those ages 18-44 and 65+ years. Conclusion: Of every 100 US Hispanic/Latino adults about 5 and 2 became overweight and obese each year, augmenting the existing high prevalence. Greater efforts are needed to prevent onset of overweight and obesity in this population from young adulthood onwards.

Compliance of systematic reviews in ophthalmology with the PRISMA statement

BackgroundSystematic reviews and meta-analyses are becoming increasingly important methods to summarize published research. Studies of ophthalmology may present additional challenges because of their potentially complex study designs. The aim of this study was to evaluate the reporting quality of systematic reviews and meta-analyses on topics in ophthalmology to determine compliance with the PRISMA guidelines. We assessed articles published between 2010 and 2015 in the five major relevant journals with the highest impact factors.MethodsThe MEDLINE and EMBASE databases were searched to identify systematic reviews published between January 2010 and December 2015 in the following 5 major ophthalmology journals: Progress in Retinal and Eye Research, Ophthalmology, Archives of Ophthalmology, American Journal of Ophthalmology, and Survey of Ophthalmology. The screening, identification, and scoring of articles were independently performed by two teams, and the results were submitted to statistical analysis to determine medians, ranges, and 95% CIs.ResultsA total of 115 articles were included. The median compliance was 15 out of 27 items (56%), the range was 5–26 (26–96%), and the inter-quartile range was 10 (37%). Compliance was highest in items related to the ‘description of rationale’ (item 3, 100%) and sequentially lower in ‘the general interpretation of results’ (item 26, 96%) and ‘the inclusion of a structured summary in the abstract’ (item 2, 90%). Compliance was poorest in the items ‘indication of review protocol and registration’ (item 5, 9%), ‘specification of risk of biases that may affect the cumulative evidence’ (item 15, 24%), and ‘description of clear objectives in the introduction’ (item 4, 26%).ConclusionThe reporting quality of systematic reviews and meta-analyses in ophthalmology should be significantly improved. While we recommend the use of the PRISMA criteria as a guideline before journal submission, additional research aimed at identifying potential barriers to compliance may be required to improve compliance with PRISMA guidelines.

Who visits an ophthalmologist and how often? Results of the German nationwide adult health survey (DEGS1)

The prevalence of eye diseases increases in the second half of life, especially cataract, glaucoma and age-related macular degeneration. In this study we examined the influencing factors for visiting an ophthalmologist in the last 12months. Visits to an ophthalmologist's practice in the last 12months and the frequency were surveyed in the German nationwide adult health survey wave 1 (DEGS1) study (baseline examination from 2008 to 2011, N= 7987, 52.6% women, age 18-79 years). Data on utilization were processed by taking the complex study design into consideration. Multivariable logistic regression analysis was used to determine associated factors including age, sex, socioeconomic status, place of residence, type of health insurance (e.g. statutory or private) and diabetes. Between the ages of 18 and 79 years, 29.3% of survey participants in Germany visited an ophthalmologist in the last year, while after the age of 60 years this was only 50.4%. Multivariable logistic regression analysis showed an association with female sex (odds ratio OR= 1.51, p< 0.001), older age, type of health insurance (private vs. statutory: OR= 0.77, p= 0.006) and diabetes (OR= 3.84, p< 0.001), but no association with socioeconomic status (p= 0.29) or place of residence (p= 0.06). Approximately one third of the German population visit an ophthalmologist at least once ayear. Especially diabetics showed ahigh utilization of ophthalmological consultations, which could be based on the interdisciplinary guidelines for early detection of diabetic eye complications.

Autogenic drainage for airway clearance in cystic fibrosis.

Autogenic drainage is an airway clearance technique that was developed by Jean Chevaillier in 1967. The technique is characterised by breathing control using expiratory airflow to mobilise secretions from smaller to larger airways. Secretions are cleared independently by adjusting the depth and speed of respiration in a sequence of controlled breathing techniques during exhalation. The technique requires training, concentration and effort from the individual. It is important to systematically review the evidence demonstrating that autogenic drainage is an effective intervention for people with cystic fibrosis. To compare the clinical effectiveness of autogenic drainage in people with cystic fibrosis with other physiotherapy airway clearance techniques. We searched the Cochrane Cystic Fibrosis Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books. We also searched the reference lists of relevant articles and reviews, as well as two trials registers (31 August 2017).Dtae of most recent search of the Cochrane Cystic Fibrosis Trials Register: 25 September 2017. We identified randomised and quasi-randomised controlled studies comparing autogenic drainage to another airway clearance technique or no therapy in people with cystic fibrosis for at least two treatment sessions. Data extraction and assessments of risk of bias were independently performed by two authors. The authors assessed the quality of the evidence using the GRADE system. The authors contacted two investigators for further information pertinent to their published studies. Searches retrieved 35 references to 21 individual studies, of which seven (n = 208) were eligible for inclusion. One study was of parallel design with the remaining six being cross-over in design; participant numbers ranged from 17 to 75. The total study duration varied between four days and two years. The age of participants ranged between seven and 63 years with a wide range of disease severity reported. Six studies enrolled participants who were clinically stable, whilst participants in one study had been hospitalised with an infective exacerbation. All studies compared autogenic drainage to one (or more) other recognised airway clearance technique. Exercise is commonly used as an alternative therapy by people with cystic fibrosis; however, there were no studies identified comparing exercise with autogenic drainage.The quality of the evidence was generally low or very low. The main reasons for downgrading the level of evidence were the frequent use of a cross-over design, outcome reporting bias and the inability to blind participants.The review's primary outcome, forced expiratory volume in one second, was the most common outcome measured and was reported by all seven studies; only three studies reported on quality of life (also a primary outcome of the review). One study reported on adverse events and described a decrease in oxygen saturation levels whilst performing active cycle of breathing techniques, but not with autogenic drainage. Six of the seven included studies measured forced vital capacity and three of the studies used mid peak expiratory flow (per cent predicted) as an outcome. Six studies reported sputum weight. Less commonly used outcomes included oxygen saturation levels, personal preference, hospital admissions or intravenous antibiotics. There were no statistically significant differences found between any of the techniques used with respect to the outcomes measured except when autogenic drainage was described as being the preferred technique of the participants in one study over postural drainage and percussion. Autogenic drainage is a challenging technique that requires commitment from the individual. As such, this intervention merits systematic review to ensure its effectiveness for people with cystic fibrosis. From the studies assessed, autogenic drainage was not found to be superior to any other form of airway clearance technique. Larger studies are required to better evaluate autogenic drainage in comparison to other airway clearance techniques in view of the relatively small number of participants in this review and the complex study designs. The studies recruited a range of participants and were not powered to assess non-inferiority. The varied length and design of the studies made the analysis of pooled data challenging.

Examining unanswered questions about the home environment and childhood obesity disparities using an incremental, mixed-methods, longitudinal study design: The Family Matters study

There are disparities in the prevalence of childhood obesity for children from low-income and minority households. Mixed-methods studies that examine home environments in an in-depth manner are needed to identify potential mechanisms driving childhood obesity disparities that have not been examined in prior research. The Family Matters study aims to identify risk and protective factors for childhood obesity in low-income and minority households through a two-phased incremental, mixed-methods, and longitudinal approach. Individual, dyadic (i.e., parent/child; siblings), and familial factors that are associated with, or moderate associations with childhood obesity will be examined. Phase I includes in-home observations of diverse families (n=150; 25 each of African American, American Indian, Hispanic/Latino, Hmong, Somali, and White families). In-home observations include: (1) an interactive observational family task; (2) ecological momentary assessment of parent stress, mood, and parenting practices; (3) child and parent accelerometry; (4) three 24-hour child dietary recalls; (5) home food inventory; (6) built environment audit; (7) anthropometry on all family members; (8) an online survey; and (9) a parent interview. Phase I data will be used for analyses and to inform development of a culturally appropriate survey for Phase II. The survey will be administered at two time points to diverse parents (n=1200) of children ages 5–9. The main aim of the current paper is to describe the Family Matters complex study design and protocol and to report Phase I feasibility data for participant recruitment and study completion. Results from this comprehensive study will inform the development of culturally-tailored interventions to reduce childhood obesity disparities.

An integrated study of human and animal infectious disease in the Lake Victoria crescent small-holder crop-livestock production system, Kenya

BackgroundThe neglected zoonotic diseases (NZD) are an understudied group that are a major cause of illness throughout the developing world. In general, little is known about the prevalence and burden of NZDs in affected communities, particularly in relation to other infectious diseases with which they are often co-endemic. We describe the design and descriptive epidemiological outputs from an integrated study of human and animal zoonotic and non-zoonotic disease in a rural farming community in western Kenya.MethodsThis cross-sectional survey involved 2113 people, their cattle (n = 983) and pigs (n = 91). People and animals were tested for infection or exposure to a wide range of zoonotic and non-zoonotic pathogens. Prevalence estimates, with adjustment for the complex study design, were derived. Evidence for spatial clustering in exposure or infection was identified using the spatial scan statistic.ResultsThere was a high prevalence of human parasitism in the community, particularly with hookworm (Ancylostoma duodenale or Necator americanus) (36.3% (95% CI 32.8–39.9)), Entamoeba histolytica/dispar (30.1% (95% CI 27.5–32.8)), and Plasmodium falciparum (29.4% (95% CI 26.8–32.0)). Human infection with Taenia spp. was also prevalent (19.7% (95% CI 16.7–22.7)), while exposure to other zoonotic pathogens was comparatively rarer (Brucella spp., 0.6% (95% CI 0.2–0.9); Coxiella burnetii, 2.2% (95% CI 1.5–2.9); Rift Valley fever, 0.5% (95% CI 0.2–0.8)). A low prevalence of exposure to Brucella spp. was observed in cattle (0.26% (95% CI 0–0.56). This was higher for Rift Valley fever virus (1.4% (95% CI 0.5–2.22)) and C. burnetii (10.0% (95% CI 7.7–12.2)). The prevalence of Taenia spp. cysticercosis was 53.5% (95% CI 48.7–58.3) in cattle and 17.2% (95% CI 9.1–25.3) in pigs. Mycobacterium bovis infection was found in 2.2% of cattle (95% CI 1.3–3.2), while the prevalence of infection with Mycobacterium spp. was 8.2% (95% CI 6.8–9.6) in people.ConclusionZoonotic infections in people and animals occur in the context of a wide range of co-endemic pathogens in a rural community in western Kenya. The wide diversity of pathogens under study provides a unique opportunity to explore the distribution and determinants of infection in a multi-pathogen, multi-host system.