LEVEL (Logical Explanations & Visualizations of Estimates in Linear mixed models): recommendations for reporting multilevel data and analyses

Institute for Social and Health Studies (ISHS

The agreement chart

Abstract Background When assessing the concordance between two methods of measurement of ordinal categorical data, summary measures such as Cohen’s (1960) kappa or Bangdiwala’s (1985) B-statistic are used. However, a picture conveys more information than a single summary measure. Methods We describe how to construct and interpret Bangdiwala’s (1985) agreement chart and illustrate its use in visually assessing concordance in several example clinical applications. Results The agreement charts provide a visual impression that no summary statistic can convey, and summary statistics reduce the information to a single characteristic of the data. However, the visual impression is personal and subjective, and not usually reproducible from one reader to another. Conclusions The agreement chart should be used to complement the summary kappa or B-statistics, not to replace them. The graphs can be very helpful to researchers as an early step to understand relationships in their data when assessing concordance

The agreement chart

Abstract Background When assessing the concordance between two methods of measurement of ordinal categorical data, summary measures such as Cohen’s (1960) kappa or Bangdiwala’s (1985) B-statistic are used. However, a picture conveys more information than a single summary measure. Methods We describe how to construct and interpret Bangdiwala’s (1985) agreement chart and illustrate its use in visually assessing concordance in several example clinical applications. Results The agreement charts provide a visual impression that no summary statistic can convey, and summary statistics reduce the information to a single characteristic of the data. However, the visual impression is personal and subjective, and not usually reproducible from one reader to another. Conclusions The agreement chart should be used to complement the summary kappa or B-statistics, not to replace them. The graphs can be very helpful to researchers as an early step to understand relationships in their data when assessing concordance

Statistical Considerations when Communicating Health Risks: Experiences from Canada, Chile, Ecuador and England Facing COVID-19

Communicating statistics in health risk communication is a fundamental part of managing public health emergencies. Effective communication requires careful planning and the anticipation of possible information demands from the population. The information should be clear, relevant, easy to understand, timely, accurate and precise, allowing the public to make informed decisions about protective behaviours. COVID-19, being a new disease, with little known about its characteristics and effects, has challenged governments and healthcare systems in all countries. This article discusses the statistical issues involved, and the experiences of risk communication in four countries – Canada, Chile, Ecuador and England. These countries have communicated risks differently, partly because of their different healthcare systems, as well as socioeconomic, cultural and political realities. During a pandemic, health authorities and governments must step up to the challenge of communicating statistical information under pressure and with urgency, when little is known about the disease, the situation is dynamic and evolving, and the general public is gripped with fear and anxiety. This is in addition to the existing challenges relating to the generation of data of different quality by diverse sources, and a public with varying levels of statistical literacy. From a statistical perspective, communiqués about risks and numbers should convey the uncertainty there is about the information, the inherent variabilities in the system, the precision and accuracy of estimates and the assumptions behind projections. Complex technical concepts, such as ‘flattening the curve’, ‘range in risk estimates’ and ‘projected trends,’ should be explained

Does the association between birth weight and blood pressure increase with age? A longitudinal study in young adults

OBJECTIVES: To assess whether the association between birth weight and blood pressure (BP) increases with age using three different statistical methods. METHODS: A representative sample of 1232 study participants born between 1974-1978 in Limache, Chile were assessed in 2000-2002, of whom 796 were reassessed in 2010-2012. An 'amplification effect' was assessed by the change in the β coefficient in the two periods, the association between birth weight and the difference of BP overtime, and the interaction between birth weight and BP in the two periods. RESULTS: Birth weight was negatively associated with SBP in 2000-2002 (β = -2.46, 95% confidence interval (CI) -3.77 to -1.16) and in 2010-2012 (β = -3.64, 95% CI -5.20 to -2.08), and with DBP in 2000-2002 (β = -1.26, 95% CI -2.23 to -0.29) , and 2010-2012 (β = -1.64, 95% CI -2.84 to -0.45) after adjustment for sex, physical activity, and BMI. There was no association between birth weight and the difference in BP between the two periods or the interaction between birth weight, BP, and time interval. CONCLUSION: Birth weight is a factor associated with BP in adults. This association increased with age, but amplification was shown only with one of the three methods

Workforce Resources for Health in Developing Countries

Abstract With increased globalization and interdependence among countries, sustained health worker migration and the complex threats of rapidly spreading infectious diseases, as well as changing lifestyles, a strong health workforce is essential. Building the human resources for health should not only include healthcare professionals like physicians and nurses, but must take into consideration community health workers, mid-level workers and strengthened primary healthcare systems to increase coverage and address the basic health needs of societies. This is especially true in low and middle-income countries where healthcare access is a critical challenge. There is a global crisis in the health workforce, expressed in acute shortages and maldistribution of health workers, geographically and professionally. This massive global shortage, though imprecise quantitatively, is estimated at more than 4 million workers. To respond to this crisis, policies and actions are needed to address the dynamics of the health labour market and the production and management of the health workforce, and to strengthen the performance of existing health systems. Schools of public health need to develop the range of capacity and leadership in addition to the traditional training of healthcare managers and researchers. Countries should first identify their health problems in order to properly address their health worker needs, retention, recruitment and training, if they are to come close to reaching the Millennium Development Goals (MDGs) for health

Coordination of international multicenter studies: Governance and administrative structure

A well-conducted multicenter study needs to assure standardization, uniformity of procedures, high data quality, and collaboration across sites. This manuscript describes the organization and dynamics of multicenter studies, focusing on governance and administrative structures among countries of diverse cultures. the organizational structure of a multicenter study is described, and a system for oversight and coordination, along with roles and responsibilities of participants in the multicenter study, are presented. the elements of a governance document are also reviewed, along with guidelines and policies for effective collaboration. the experience of an ongoing multi-country collaboration, the World Studies of Abuse in the Family Environment (World-SAFE), illustrates the implementation of these guidelines. It is essential that multicenter studies have an objective coordinating center and that the investigators jointly develop a written governance document to enable collaboration and preserve collegiality among participating investigators. the English version of this paper is available too at: http://www.insp.mx/salud/index.html.Univ N Carolina, Chapel Hill, NC USAUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilUniv Philippines, Manila, PhilippinesUniv La Frontera, Temuco, ChileUniversidade Federal de São Paulo, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

SAMURAI: Sensitivity analysis of a meta-analysis with unpublished but registered analytical investigations (software)

Abstract Background The non-availability of clinical trial results contributes to publication bias, diminishing the validity of systematic reviews and meta-analyses. Although clinical trial registries have been established to reduce non-publication, the results from over half of all trials registered in ClinicalTrials.gov remain unpublished even 30 months after completion. Our goals were i) to utilize information available in registries (specifically, the number and sample sizes of registered unpublished studies) to gauge the sensitivity of a meta-analysis estimate of the effect size and its confidence interval to the non-publication of studies and ii) to develop user-friendly open-source software to perform this quantitative sensitivity analysis. Methods The open-source software, the R package SAMURAI, was developed using R functions available in the R package metafor. The utility of SAMURAI is illustrated with two worked examples. Results Our open-source software SAMURAI, can handle meta-analytic datasets of clinical trials with two independent treatment arms. Both binary and continuous outcomes are supported. For each unpublished study, the dataset requires only the sample sizes of each treatment arm and the user predicted ‘outlook’ for the studies. The user can specify five outlooks ranging from ‘very positive’ (i.e., very favorable towards intervention) to ‘very negative’ (i.e., very favorable towards control). SAMURAI assumes that control arms of unpublished studies have effects similar to the effect across control arms of published studies. For each experimental arm of an unpublished study, utilizing the user-provided outlook, SAMURAI randomly generates an effect estimate using a probability distribution, which may be based on a summary effect across published trials. SAMURAI then calculates the estimated summary treatment effect with a random effects model (DerSimonian & Laird method), and outputs the result as a forest plot. Conclusions To our knowledge, SAMURAI is currently the only tool that allows systematic reviewers to incorporate information about sample sizes of treatment groups in registered but unpublished clinical trials in their assessment of the potential impact of publication bias on meta-analyses. SAMURAI produces forest plots for visualizing how inclusion of registered unpublished studies might change the results of a meta-analysis. We hope systematic reviewers will find SAMURAI to be a useful addition to their toolkit

Worldwide Prevalence and Burden of Functional Gastrointestinal Disorders, Results of Rome Foundation Global Study

DGBI; IBS; EpidemiologyDGBI; IBS; EpidemiologiaDGBI; IBS; EpidemiologíaBackground & Aims Although functional gastrointestinal disorders (FGIDs), now called disorders of gut-brain interaction, have major economic effects on health care systems and adversely affect quality of life, little is known about their global prevalence and distribution. We investigated the prevalence of and factors associated with 22 FGIDs, in 33 countries on 6 continents. Methods Data were collected via the Internet in 24 countries, personal interviews in 7 countries, and both in 2 countries, using the Rome IV diagnostic questionnaire, Rome III irritable bowel syndrome questions, and 80 items to identify variables associated with FGIDs. Data collection methods differed for Internet and household groups, so data analyses were conducted and reported separately. Results Among the 73,076 adult respondents (49.5% women), diagnostic criteria were met for at least 1 FGID by 40.3% persons who completed the Internet surveys (95% confidence interval [CI], 39.9–40.7) and 20.7% of persons who completed the household surveys (95% CI, 20.2–21.3). FGIDs were more prevalent among women than men, based on responses to the Internet survey (odds ratio, 1.7; 95% CI, 1.6–1.7) and household survey (odds ratio, 1.3; 95% CI, 1.3–1.4). FGIDs were associated with lower quality of life and more frequent doctor visits. Proportions of subjects with irritable bowel syndrome were lower when the Rome IV criteria were used, compared with the Rome III criteria, in the Internet survey (4.1% vs 10.1%) and household survey (1.5% vs 3.5%). Conclusions In a large-scale multinational study, we found that more than 40% of persons worldwide have FGIDs, which affect quality of life and health care use. Although the absolute prevalence was higher among Internet respondents, similar trends and relative distributions were found in people who completed Internet vs personal interviews.The study was funded, in part, by research grants from Ironwood, Shire, Allergan, and Takeda. The study in Malaysia was funded by the Fundamental Research Grant Scheme (FRGS) of the Ministry of Education of Malaysia (Reference: 203.PPSP.6171192). The study in Israel was funded by Takeda-Israel. The study in Romania was funded by the Romanian Society of Neurogastroenterology. None of the funders was involved in the planning, design, implementation, statistical analyses or any other aspect of the study including preparation of the paper or knowledge of its contents